Advertisement

Food Waste in the National School Lunch Program 1978-2015: A Systematic Review

Open AccessPublished:August 12, 2017DOI:https://doi.org/10.1016/j.jand.2017.06.008

      Abstract

      Background

      Food waste studies have been used for more than 40 years to assess nutrient intake, dietary quality, menu performance, food acceptability, cost, and effectiveness of nutrition education in the National School Lunch Program (NSLP).

      Objective

      Describe methods used to measure food waste and respective results in the NSLP across time.

      Methods

      A systematic review using PubMed, Science Direct, Informaworld, and Institute of Scientific Information Web of Knowledge was conducted using the following search terms: waste, school lunch, plate waste, food waste, kitchen, half method, quarter method, weight, and photography. Studies published through June 2015 were included. The systematic review followed preferred reporting items for systematic reviews and meta-analyses recommendations.

      Results

      The final review included 53 articles. Food waste methodologies included in-person visual estimation (n=11), digital photography (n=11), direct weighing (n=23), and a combination of in-person visual estimation, digital photography, and/or direct weighing (n=8). A majority of studies used a pre–post intervention or cross-sectional design. Fruits and vegetables were the most researched dietary component on the lunch tray and yielded the greatest amount of waste across studies.

      Conclusions

      Food waste is commonly assessed in the NSLP, but the methods are diverse and reporting metrics are variable. Future research should focus on establishing more uniform metrics to measure and report on food waste in the NSLP. Consistent food waste measurement methods will allow for better comparisons between studies. Such measures may facilitate better decision making about NSLP practices, programs, and policies that influence student consumption patterns across settings and interventions.

      Keywords

      The National School Lunch Program (NSLP) serves more than 31 million children in more than 100,000 schools each school day.

      US Department of Agriculture, Food and Nutrition Service. Child nutrition programs. http://www.fns.usda.gov/school-meals/child-nutrition-programs. Published February 2016. Accessed March 2016.

      US Department of Agriculture, Food and Nutrition Service. National School Lunch Program fact sheet. http://www.fns.usda.gov/cnd/lunch/AboutLunch/NSLPFactSheet.pdf. Published September 2013. Accessed March 2016.

      The NSLP aims to offer balanced meals to schoolchildren, provided at free or reduced costs for low-income populations and subsidized by the federal government.

      US Department of Agriculture, Food and Nutrition Service. National School Lunch Program fact sheet. http://www.fns.usda.gov/cnd/lunch/AboutLunch/NSLPFactSheet.pdf. Published September 2013. Accessed March 2016.

      The Healthy Hunger Free Kids Act of 2010 required updated nutrition standards for schools based on the most recent Dietary Guidelines for Americans and Institute of Medicine recommendations.

      US Government Publishing Office. Nutrition standards in the national school lunch and school breakfast programs: Final rule. http://www.gpo.gov/fdsys/pkg/FR-2012-01-26/html/2012-1010.htm. Published January 26, 2012. 77. Accessed March 2016.

      The requirements consist of five meal components: fruits, vegetables, whole grains, low-fat dairy, protein, and sodium content in a specified range. The serving size and caloric limits for each meal for children enrolled in grades kindergarten through 12 are based on age group. A lunch provided to a student must consist of three out of the five components offered to be considered a reimbursable meal, with one of the components being a fruit or vegetable.

      US Government Publishing Office. Nutrition standards in the national school lunch and school breakfast programs: Final rule. http://www.gpo.gov/fdsys/pkg/FR-2012-01-26/html/2012-1010.htm. Published January 26, 2012. 77. Accessed March 2016.

      The NSLP setting provides an important opportunity for researchers and practitioners to study how much and what types of nutrients children consume and waste. The lunchroom is experimental in nature because menus are designed (and can be changed) by local school food authorities per national nutrition standards, food portions are standardized, and many students dine in the cafeteria every school day. Study results with high external validity have far reaching implications for the NSLP nationwide.
      Since the 1970s,
      US Department of Agriculture, Food and Nutrition Service
      General Guidelines for Determining Food Acceptability: Procedures for Plate Waste Studies.
      researchers have used plate and food waste studies to observe nutrient intake, dietary quality, menu performance, food acceptability, cost, and effectiveness of nutrition education in the NSLP. Plate and food waste are used synonymously throughout most of the school foods research literature and will herein be referred to as food waste. Food waste studies measure the uneaten edible portion of food served to an individual.
      • Byker C.J.
      • Farris A.R.
      • Marcenelle M.
      • Davis G.C.
      • Serrano E.L.
      Food waste in a school nutrition program after implementation of new lunch program guidelines.
      Food waste methodology can measure several important food and nutrition outcomes,

      Buzby JC, Guthrie JF. Plate Waste in School Nutrition Programs: Final Report to Congress. March 2002. Publication no. EFAN-02-009. https://www.ers.usda.gov/webdocs/publications/43131/31216_efan02009.pdf?v=41423. Accessed June 2, 2017.

      including the amount of a specific nutrient available, consumed, and wasted, the types of food groups most likely being eaten or thrown away, compliance with nutrition practices and policies, the effect of nutrition education on food choice and consumption, acceptability of menu items, and the influence of waste on an institution’s budget and on natural resources. The resulting data can be used to drive important changes in practices, programs, and policies in a school lunch program. In addition, in recent years, global and national food waste campaigns have further amplified the importance of reducing food waste.
      • Gustavsson J.
      • Cederberg C.
      • Sonesson U.
      • van Otterdijk R.
      • Meybeck A.
      Global Food Losses and Food Waste—Extent, Causes and Prevention.
      • Buzby J.C.
      • Wells H.F.
      • Hyman J.
      The Estimated Amount, Value, and Calories of Postharvest Food Losses at the Retail and Consumer Levels in the United States.
      The purpose of this systematic review was to provide a summary of the literature describing the measurement and results of food waste studies in the NSLP across time.

      Methods

      Search Strategy

      Articles included in this systematic literature review were extracted from PubMed, Science Direct, Informaworld, and ISI Web of Knowledge using the preferred reporting items for systematic reviews and meta-analyses (PRISMA) format published through June 2015.
      • Moher D.
      • Liberati A.
      • Tetzlaff J.
      • Altman D.G.
      The PRISMA group
      Preferred reporting items for systematic reviews and meta-analyses: The PRISMA statement.
      When testing key words, these databases yielded relevant articles. The authors tested potential key words related to NSLP and food waste through mock searches to ensure that the final list of terms captured relevant articles that met inclusion and exclusion criteria. Keywords entered with Boolean operators included waste, school lunch, plate waste, food waste, kitchen, half method, quarter method, weight, and photography. The following are two search strategies used in Science Direct: waste OR “food waste” OR “plate waste” OR “kitchen waste” AND school AND lunch; waste OR “food waste” OR “plate waste” AND school AND lunch AND “quarter method” OR “half method” OR weight OR photography. No limits or filters were used in the search. The search strategy was modified for individual databases.

      Study Selection

      The main criterion for inclusion was the explicit use and description of a method to measure food waste in the NSLP. Articles included were peer-reviewed, written in the English language, and based on studies conducted in the United States covering the NSLP. Journal articles that collected primary data were considered. Articles were excluded in cases where they did not focus on the NSLP, were conducted outside of the United States, did not measure food waste, or presented a review of literature. Meeting abstracts were excluded due to limited information about methodology conducted. Cross-sectional, intervention, quasiexperimental, randomized controlled trial, and mixed-methods study designs and methods were considered.

      Data Extraction

      Two reviewers first evaluated articles by titles, abstracts, and key words. In cases where food waste and kindergarten through 12th-grade schools were discussed in the title of an article, abstract, or key words, the full article was reviewed to determine relevance. Titles and abstracts that met the inclusion criteria were recorded for full text review. The references in each article included were reviewed to determine whether any other additional studies were relevant, although no additional articles were found that were not already captured in the search. The authors reviewed each article independently and met to determine inclusion or exclusion; disagreements were resolved via discussion.
      For each article included in the review, one coder collected and entered data into an extraction template. Information recorded included: first author and year published, purpose, study design and specific data collection method, school type, number of schools involved, location of school, number of students, free and reduced NSLP eligibility, race/ethnicity, grade level or age, dietary component measures, duration and frequency of the data collected, food waste results, other relevant findings to food waste, and whether conducted before or after implementation of the NSLP standards updated by the Healthy Hunger Free Kids Act of 2010. The categories for data extraction were determined based on factors that may inform a researcher’s decision to select a particular food waste measurement method. For example, it may be useful for researchers to understand the various ways results are reported when using a particular method (ie, waste of nutrients, specific foods, or food groups). The data collected, along with the publication, were reviewed by at least two additional coders to ensure accuracy; all disagreements were resolved by discussing inclusion and exclusion criteria to reach consensus.

      Quality Appraisal of Individual Studies

      Study quality was assessed using the Effective Public Health Policy Project (EPHPP) Quality Assessment Tool.

      Effective Public Health Practice Project Quality Assessment Tool. http://www.ephpp.ca/tools.html. Accessed May 1, 2017.

      The EPHPP Quality Assessment Tool provides researchers with criteria to evaluate studies on the basis of selection bias, study design, confounders, blinding, data collection methods, withdraws and dropouts, intervention integrity, and analysis. Each criteria is scored numerically according to provided guidelines by the EPHPP Quality Assessment Tool as strong (score=1), moderate (score=2), or weak (score=3). Subsequently, the entire article is rated as strong (no weak ratings), moderate (one weak rating), or weak (two or more weak ratings).
      This study was exempt from institutional review board review because there was no interaction with human subjects.

      Results

      A total of 10,892 articles were retrieved using the database search. After eliminating duplicates and articles that did not meet inclusion criteria based on title and abstract screening, 66 articles remained for content review. After reviewing the full articles, 13 studies were excluded due to the following reasons: four were conducted outside of the United States; four did not involve the NSLP; three were in preschools; and two were conference abstracts, not full articles (see the Figure).
      Figure thumbnail gr1
      FigurePreferred reporting items for systematic reviews and meta-analyses (PRISMA) 2009 flow diagram for selecting studies to include in the systematic review of food waste in the National School Lunch Program across time. Terms used in this search included a combination of the following: waste, school lunch, plate waste, food waste, kitchen waste, half method, quarter method, weight, and photography. aRelevance determined by inclusion and exclusion criteria. Inclusion criteria for articles were peer reviewed, English language, and conducted in US National School Lunch Program (NSLP). Exclusion criteria for articles were no focus on the US NSLP, food waste not used as a measurement tool, review of literature, or a conference meeting abstract. ISI=Institute for Scientific Information.
      The 53 studies included in this review used four major types of food waste measurement methodologies: in-person visual estimation (n=11) (Table 1), digital photography (n=11) (Table 2), direct weighing (n=23) (Table 3), and a combination of in-person visual estimation, digital photography, and/or direct weighing (n=8) (Table 4). With regard to study design and methods, most studies identified interventions with a pre–post or pre–post-follow-up design (n=20) or cross-sectional (n=23), two were quasiexperimental, two were mixed methods, one study was longitudinal, and five were randomized controlled trials. Fourteen studies were rated as strong, 20 studies were rated as moderate, and 19 studies were rated as weak according to the EPHPP Quality Assessment Tool. Studies labeled as moderate were likely to have a weak rating for study design, whereas studies labeled as weak were likely to have weak ratings for selection bias or confounders and study design. See Table 1, Table 2, Table 3, Table 4 for quality assessment ratings.
      Table 1In-person visual estimation through observation for food waste studies conducted in the National School Lunch Program
      Reference
      Green and colleagues, 1987
      • Green N.R.
      • Munroe S.G.
      Evaluating nutrient-based nutrition education by nutrition knowledge and school lunch plate waste.
      Reger and colleagues, 1996
      • Reger C.
      • O’Neil C.E.
      • Nicklas T.A.
      • Myers L.
      • Berenson G.S.
      Plate waste of school lunches served to children in a low socioeconomic elementary school in South Louisiana.
      Auld and colleagues, 1999
      • Auld G.W.
      • Romaniello C.
      • Heimendinger J.
      • Hambidge C.
      • Hambidge M.
      Outcomes from a school-based nutrition education program alternating special resource teachers and classroom teachers.
      Blom-Hoffman and colleagues, 2004
      • Blom-Hoffman J.
      • Kelleher C.
      • Power T.J.
      • Leff S.S.
      Promoting healthy food consumption among young children: Evaluation of a multi-component nutrition education program.
      Just and colleagues, 2013
      • Just D.
      • Price J.
      Default options, incentives and food choices: Evidence from elementary-school children.
      Wansink and colleagues, 2013
      • Wansink B.
      • Just D.R.
      • Hanks A.S.
      • Smith L.E.
      Pre-sliced fruit in school cafeterias: Children’s selection and intake.
      Just and colleagues, 2014
      • Just D.R.
      • Wansink B.
      • Hanks A.S.
      Chefs move to schools. A pilot examination of how chef-created dishes can increase school lunch participation and fruit and vegetable intake.
      Data were collected to assess food waste after new school lunch meal patterns were implemented beginning 2012.
      Cullen and colleagues, 2015
      • Cullen K.W.
      • Chen T.A.
      • Dave J.M.
      • Jensen H.
      Differential improvements in student fruit and vegetable consumption in response to the new National School Lunch Program regulations: A pilot study.
      Cullen and colleagues, 2015
      • Cullen K.W.
      • Chen T.A.
      • Dave J.M.
      Changes in foods selected and consumed after implementation of the new National School Lunch Program meal patterns in southeast Texas.
      Data were collected to assess food waste after new school lunch meal patterns were implemented beginning 2012.
      Price and colleagues, 2015
      • Price J.
      • Just D.R.
      Lunch, recess and nutrition: Responding to time incentives in the cafeteria.
      Wansink and colleagues, 2015
      • Wansink B.
      • Hanks A.S.
      • Just D.R.
      A plant to plate pilot: A cold-climate high school garden increased vegetable selection but also waste.
      Study designI
      I=intervention.
      Pre-post-follow-up intervention.
      CS
      CS=cross-sectional.
      I
      Pre-post intervention.
      RCT
      RCT=randomized controlled trial.
      I
      Pre-post intervention.
      RCTI
      Pre-post intervention.
      RCTI
      Pre-post intervention.
      I
      Pre-post intervention.
      I
      Pre-post intervention.
      Specific data collection method½
      ½=half waste method.
      A + sign was recorded for more than half of food wasted and – sign was recorded for less than half of food wasted.
      6
      6=six-point scale scored as 1=ate all of food to 6=ate none of food.
      E
      E=estimation.
      6
      Measured with 6-point scale: 5=91% to 100%; 4=76% to 90%; 3=51% to 75%; 2=26% to 50%; 1=11% to 25%; 0=0% to 10%.
      ½
      Measured in increments of ½ a serving.
      ¼
      ¼=quarter waste method.
      Measured in increments of none, ¼, ½, ¾, or all wasted.
      ¼
      Measured in increments of none, ¼, ½, ¾, or all wasted.
      ¼
      Measured in increments of none, ¼, ½, ¾, or all wasted.
      ¼
      Measured in increments of none, ¼, ½, ¾, or all wasted.
      ½
      Measured in increments of ½ a serving.
      ¼
      Measured in increments of none, ¼, ½, ¾, or all wasted.
      Type and no. of schools
       Elementary114118887
       Middle64
       High11
      Grade level33-62-4Kindergarten-1NR
      NR=not reported with specificity.
      NRNRKindergarten-8NR1-6NR
      Average percent wasted for dietary components measured
      In some cases, the average percent waste within a dietary component was reported within the cited article. In other cases, this study’s authors calculated average percent wasted within a dietary component when research design collected waste across multiple intervention periods. When percent consumed was reported (instead of percent waste), this study’s authors calculated average percent waste by subtracting the percent consumed from 100% and, if necessary, averaged across multiple intervention periods or groups.
       Grains/bread372734
       Vegetables1258
      ◊=study indicated dietary component measured but not average percent wasted within dietary component.
      19483219
       Fruits/fruit juice313941
      Specific macro- and/or micronutrients measured in whole meal.
      152723
       Meat/meat alternate118
       Milk50171827
       Other33
      Specific macro- and/or micronutrients measured in whole meal.
      62
      Measured waste of a mixed entrée.
      11
      Measured waste of a mixed entrée.
      95
      Measured waste of legumes.
      64
      Measured waste of legumes.
      Days of food waste data collection
      Data calculated as number of days reported for study multiplied by number of schools involved in food waste collections.
      7020NR3NR63NRNR143
      No. of waste observations
      Data reported according to study as individual food items or entire student tray.
      123240502NR47,4146403,3301,5761,04522,939554
      Effective public health practice project quality rating

      Effective Public Health Practice Project Quality Assessment Tool. http://www.ephpp.ca/tools.html. Accessed May 1, 2017.

      StrongWeakStrongStrongModerateStrongModerateStrongStrongStrongStrong
      a Data were collected to assess food waste after new school lunch meal patterns were implemented beginning 2012.
      b I=intervention.
      c Pre-post-follow-up intervention.
      d CS=cross-sectional.
      e Pre-post intervention.
      f RCT=randomized controlled trial.
      g ½=half waste method.
      h A + sign was recorded for more than half of food wasted and – sign was recorded for less than half of food wasted.
      i 6=six-point scale scored as 1=ate all of food to 6=ate none of food.
      j E=estimation.
      k Measured with 6-point scale: 5=91% to 100%; 4=76% to 90%; 3=51% to 75%; 2=26% to 50%; 1=11% to 25%; 0=0% to 10%.
      l Measured in increments of ½ a serving.
      m ¼=quarter waste method.
      n Measured in increments of none, ¼, ½, ¾, or all wasted.
      o NR=not reported with specificity.
      p In some cases, the average percent waste within a dietary component was reported within the cited article. In other cases, this study’s authors calculated average percent wasted within a dietary component when research design collected waste across multiple intervention periods. When percent consumed was reported (instead of percent waste), this study’s authors calculated average percent waste by subtracting the percent consumed from 100% and, if necessary, averaged across multiple intervention periods or groups.
      q ◊=study indicated dietary component measured but not average percent wasted within dietary component.
      r Specific macro- and/or micronutrients measured in whole meal.
      s Measured waste of a mixed entrée.
      t Measured waste of legumes.
      u Data calculated as number of days reported for study multiplied by number of schools involved in food waste collections.
      v Data reported according to study as individual food items or entire student tray.
      Table 2Visual estimation through digital photography for food waste studies conducted in the National School Lunch Program
      Reference
      Marlette and colleagues, 2005
      • Marlette M.A.
      • Templeton S.B.
      • Panemangalore M.
      Food type, food preparation, and competitive food purchases impact school lunch plate waste by sixth-grade students.
      Martin and colleagues, 2006
      • Martin C.K.
      • Newton R.L.
      • Anton S.D.
      • et al.
      Measurement of children's food intake with digital photography and the effects of second servings upon food intake.
      Martin and colleagues, 2010
      • Martin C.K.
      • Thomson J.L.
      • LeBlanc M.M.
      • et al.
      Children in school cafeterias select foods containing more saturated fat and energy than the Institute of Medicine Recommendations.
      Smith and colleagues, 2013
      • Smith S.L.
      • Cunningham-Sabo L.
      Food choice, plate waste and nutrient intake of elementary- and middle-school students participating in the US National School Lunch Program.
      Williamson and colleagues, 2013
      • Williamson D.A.
      • Han H.
      • Johnson W.D.
      • Martin C.K.
      • Newton R.L.
      Modification of the school cafeteria environment can impact childhood nutrition: Results from the Wise Mind and LA Health studies.
      Bontrager and colleagues, 2014
      • Bontrager Yoder A.B.
      • Liebhart J.L.
      • McCarty D.J.
      • et al.
      Farm to elementary school programming increases access to fruits and vegetables and increases their consumption among those with low intake.
      Bontrager and colleagues, 2014
      • Bontrager Yoder A.B.
      • Schoeller D.A.
      Fruits and vegetables displace, but do not decrease, total energy in school lunches.
      Hubbard and colleagues, 2014
      • Hubbard K.L.
      • Bandini L.G.
      • Folta C.
      • et al.
      Impact of a Smarter Lunchroom intervention on food selection and consumption among adolescents and young adults with intellectual and developmental disabilities in a residential school setting.
      Data were collected to assess food waste after new school lunch meal patterns were implemented, beginning 2012.
      Alaimo and colleagues, 2015
      • Alaimo K.
      • Carlson J.J.
      • Pfeiffer K.A.
      • et al.
      Project FIT: A school, community and social marketing intervention improves healthy eating among low-income elementary school children.
      Bontrager and colleagues, 2015
      • Bontrager Yoder A.B.
      • Foecke L.L.
      • Schoeller D.A.
      Factors affecting fruit and vegetable school lunch waste in Wisconsin elementary schools participating in Farm to School programs.
      Data were collected to assess food waste after new school lunch meal patterns were implemented, beginning 2012.
      Monlezun and colleagues, 2015
      • Monlezun D.J.
      • Ly D.
      • Rolfsen M.
      • et al.
      Digital photography assessment of 1,750 elementary and middle school student lunch meals demonstrates improved nutrition with increased exposure to hands-on cooking and gardening classes.
      Data were collected to assess food waste after new school lunch meal patterns were implemented, beginning 2012.
      Study designCS
      CS=cross-sectional.
      CS
      Cross-sectional study used for validation purposes.
      CSCSRCT
      RCT=randomized controlled trial.
      I
      I=intervention.
      Pre-post intervention.
      CSI
      Pre-post intervention.
      I
      Pre-post intervention.
      I
      Pre-post intervention.
      CS
      Specific data collection method
      I=intervention.
      RP
      RP=raw percent, meaning percent of food selection and plate waste in photograph compared with reference photographed and weighed portion.
      RPRPPI
      PI=percent increments, meaning percent increments (eg, in 10% or 25% increments) of food selection and plate waste in photograph compared with reference photographed and weighed portion.
      PIPIPIPIPIPIPI
      Type and no. of schools
       Elementary33321896111
       Middle3121
       Other1
      Grade level664-61-84-63-53-5NR
      NR=not reported with specificity.
      3-53-5Kindergarten-8
      Average percent wasted for dietary components measured
      Data calculated as number of days reported for study multiplied by number of schools involved in food waste collections.
       Grains/bread16
      ◊=study indicated dietary component measured but not average percent wasted within dietary component.
      2732
       Vegetables3237
      Fruits and vegetables combined.
      32
       Fruits/fruit juice3840
       Meat/meat alternate21
       Milk153027
       Other32
      Measured waste of a mixed entrée.
      Measured waste of a mixed entrée.
      Specific macro- and/or micronutrients measured in whole meal.
      Specific macro- and/or micronutrients measured in whole meal.
      22
      Measured waste of a mixed entrée.
      Specific macro- and/or micronutrients measured in whole meal.
      Measured waste of legumes.
      Measured waste of a mixed entrée.
      Measured waste of a mixed entrée.
      Weight of fluid milk remaining was determined using the full weight and empty container weight of the carton.
      Days of food waste data collection
      In some cases, the average percent waste within a dietary component was reported within the cited article. In other cases, this study’s authors calculated average percent wasted within a dietary component when research design collected waste across multiple intervention periods. When percent consumed was reported (instead of percentage waste), this study’s authors calculated average percent waste by subtracting the percent consumed from 100% and, if necessary, averaged across multiple intervention periods or groups.
      245323364321012NR5
      No. of waste observations
      Data reported according to study as individual food items or entire student tray.
      7432152,049899NR
      Pre-post intervention.
      4,4512,2926441,1927,1171,750
      Effective public health project practice quality rating

      Effective Public Health Practice Project Quality Assessment Tool. http://www.ephpp.ca/tools.html. Accessed May 1, 2017.

      WeakWeakWeakWeakStrongWeakWeakModerateModerateModerateWeak
      a Data were collected to assess food waste after new school lunch meal patterns were implemented, beginning 2012.
      b CS=cross-sectional.
      c Cross-sectional study used for validation purposes.
      d RCT=randomized controlled trial.
      e I=intervention.
      f Pre-post intervention.
      g RP=raw percent, meaning percent of food selection and plate waste in photograph compared with reference photographed and weighed portion.
      h PI=percent increments, meaning percent increments (eg, in 10% or 25% increments) of food selection and plate waste in photograph compared with reference photographed and weighed portion.
      i NR=not reported with specificity.
      j Data calculated as number of days reported for study multiplied by number of schools involved in food waste collections.
      k ◊=study indicated dietary component measured but not average percent wasted within dietary component.
      l Fruits and vegetables combined.
      m Measured waste of a mixed entrée.
      n Specific macro- and/or micronutrients measured in whole meal.
      o Measured waste of legumes.
      p In some cases, the average percent waste within a dietary component was reported within the cited article. In other cases, this study’s authors calculated average percent wasted within a dietary component when research design collected waste across multiple intervention periods. When percent consumed was reported (instead of percentage waste), this study’s authors calculated average percent waste by subtracting the percent consumed from 100% and, if necessary, averaged across multiple intervention periods or groups.
      q Data reported according to study as individual food items or entire student tray.
      Table 3Direct weighing for food waste studies in the National School Lunch Program
      Data were collected to assess food waste after new school lunch meal patterns implemented beginning 2012.
      Reference
      Jansen and colleagues, 1978
      • Jansen G.R.
      • Harper J.M.
      Consumption and plate waste of menu items served in the National School Lunch Program.
      Davidson and colleagues, 1979
      • Davidson F.R.R.
      Critical factors for school lunch acceptance in Washington, D.C.
      Comstock and colleagues, 1982
      • Comstock E.M.
      • Symington L.E.
      Distributions of serving sizes and plate waste in school lunches: Implications for measurement.
      Getlinger and colleagues, 1996
      • Getlinger M.J.
      • Laughlin V.T.
      • Bell E.
      • Akre C.
      • Arjmandi B.H.
      Food waste is reduced when elementary-school children have recess before lunch.
      Whatley and colleagues, 1996
      • Whatley J.E.
      • Donnelly J.E.
      • Jacobsen D.J.
      • Hill J.O.
      • Carlson M.K.
      Energy and macronutrient consumption of elementary school children served modified lower fat and sodium lunches or standard higher fat and sodium lunches.
      Adams and colleagues, 2005
      • Adams M.A.
      • Pelletier R.L.
      • Zive M.M.
      • Sallis J.F.
      Salad bars and fruit and vegetable consumption in elementary schools: A plate waste study.
      Toma and colleagues, 2009
      • Toma A.
      • Omary M.B.
      • Marquart L.F.
      • et al.
      Children’s acceptance, nutritional, and instrumental evaluations of whole grain and soluble fiber enriched foods.
      Hoffman and colleagues, 2010
      • Hoffman J.A.
      • Franko D.L.
      • Thompson D.R.
      • Power T.J.
      • Stallings V.A.
      Longitudinal behavioral effects of a school-based fruit and vegetable promotion program.
      Lazor and colleagues, 2010
      • Lazor K.
      • Chapman N.
      • Levine E.
      Soy goes to school: Acceptance of healthful, vegetarian options in Maryland middle school lunches.
      Chu and colleagues, 2011
      • Chu L.
      • Warren C.A.
      • Sceets C.E.
      • et al.
      Acceptance of two US Department of Agriculture commodity whole-grain products: A school-based study in Texas and Minnesota.
      Hoffman and colleagues, 2011
      • Hoffman J.A.
      • Thompson D.R.
      • Franko D.L.
      • et al.
      Decaying behavioral effects in a randomized, multi-year fruit and vegetable intake intervention.
      Cohen and colleagues, 2012
      • Cohen J.F.W.
      • Smit L.A.
      • Parker E.
      • et al.
      Long-term impact of a chef on school lunch consumption: Findings from a 2-Year pilot study in Boston middle schools.
      Yon and colleagues, 2012
      • Yon B.A.
      • Johnson R.K.
      • Stickle T.R.
      School children’s consumption of lower-calorie flavored milk: A plate waste study.
      Cohen and colleagues, 2013
      • Cohen J.F.W.
      • Richardson S.
      • Austin S.B.
      • Economos C.D.
      • Rimm E.B.
      School lunch waste among middle school students: Nutrients consumed and costs.
      Ramsay and colleagues, 2013
      • Ramsay S.
      • Safaii S.
      • Croschere T.
      • Branen L.J.
      • Weist M.
      Kindergarteners’ entrée intake increases when served a larger entrée portion in school lunch: A quasi-experiment.
      Byker and colleague, 2014
      • Byker C.J.
      • Farris A.R.
      • Marcenelle M.
      • Davis G.C.
      • Serrano E.L.
      Food waste in a school nutrition program after implementation of new lunch program guidelines.
      Cohen and colleaugues, 2014
      • Cohen J.F.W.
      • Richardson S.
      • Parker E.
      • Catalano P.J.
      • Rimm E.B.
      Impact of the new US Department of Agriculture school meals standards on food selection, consumption and waste.
      Hunsberger and colleagues, 2014
      • Hunsberger M.
      • McGinnis P.
      • Smith J.
      • Beamer B.A.
      • O’Malley J.
      Elementary school children’s recess schedule and dietary intake at lunch: A community-based participatory research partnership pilot study.
      Jones and colleagues, 2014
      • Jones B.A.
      • Madden G.J.
      • Wengreen H.J.
      • Aguilar S.S.
      • Desjardins E.A.
      Gamification of dietary decision-making in an elementary-school cafeteria.
      Jones and colleagues, 2014
      • Jones B.A.
      • Madden G.J.
      • Wengreen H.J.
      The FIT Game: Preliminary evaluation of a gamification approach to increasing fruit and vegetable consumption in school.
      Cohen and colleagues, 2015
      • Cohen J.F.W.
      • Richardson S.A.
      • Cluggish S.A.
      • et al.
      Effects of choice architecture and chef-enhanced meals on the selection and consumption of healthier school foods: A randomized clinical trial.
      Miller and colleagues, 2015
      • Miller N.
      • Reicks M.
      • Redden J.P.
      • et al.
      Increasing portion sizes of fruits and vegetables in an elementary school lunch program can increase fruit and vegetable consumption.
      Wilkie and colleagues, 2015
      • Wilke A.C.
      • Graunke R.E.
      • Cornejo C.
      Food waste auditing at three Florida schools.
      Study designQ
      Q=quasiexperimental.
      CS
      CS=cross-sectional.
      CSI
      I=intervention.
      Pre-post intervention.
      I
      Pre-post-follow-up intervention.
      CSI
      Pre-post intervention.
      I
      Pre-post-follow-up intervention.
      CSCSL
      L=longitudnal.
      CSMM
      MM=mixed methods.
      CSQCSI
      Pre-post intervention.
      MMI
      Pre-post intervention.
      I
      Pre-post intervention.
      RCT
      RCT=randomized controlled trial.
      I
      Pre-post intervention.
      CS
      Specific data collection methodDW
      DW=direct weighing.
      Difference weight of plate waste for each food minus weight of average selected serving.
      DW
      Percent plate waste calculated by dividing the weight of edible food waste by the mean serving weight.
      DW
      Difference weight of plate waste for each food minus weight of average selected serving.
      DW
      Difference weight of plate waste for each food minus weight of average selected serving.
      DW
      Percent plate waste calculated by dividing the weight of edible food waste by the mean serving weight.
      DW
      Difference weight of plate waste for each food minus pre consumption selections for all students’ plates.
      DW
      Difference weight of plate waste for each food minus weight of average selected serving.
      DW
      Difference weight of plate waste for each food minus weight of average selected serving.
      DW
      Difference weight of plate waste for each food minus weight of average selected serving.
      DW
      Difference weight of plate waste for each food minus weight of average selected serving.
      DW
      Difference weight of plate waste for each food minus weight of average selected serving.
      DW
      Difference weight of plate waste for each food minus weight of average selected serving.
      DW
      Weight of fluid milk remaining was determined using the full weight and empty container weight of the carton.
      DW
      Difference weight of plate waste for each food minus weight of average selected serving.
      DW
      Difference weight of plate waste for each food minus weight of average selected serving.
      DW
      Difference weight of plate waste for each food minus weight of average selected serving.
      DW
      Difference weight of plate waste for each food minus weight of average selected serving.
      DW
      Difference weight of plate waste for each food minus weight of average selected serving.
      DW
      Fruit and vegetable consumption was calculated by weighing all produce prepared and subtracting unserved and waste weights, divided by number of students.
      DW
      Fruit and vegetable consumption was calculated by weighing all produce prepared and subtracting unserved and waste weights, divided by number of students.
      DW
      Difference weight of plate waste for each food minus weight of average selected serving.
      DW
      Difference weight of plate waste for each food minus weight of average selected serving.
      DW
      Waste was sorted by hand and weighed on a digital scale.
      Type and no. of schools
       Elementary292311124141249114
      At least one study school was not identified as elementary or middle, but identified kindergarten through eighth grade or was not identified as middle or high, but identified as grades six through 12.
      11
      At least one study school was not identified as elementary or middle, but identified kindergarten through eighth grade or was not identified as middle or high, but identified as grades six through 12.
      1711
       Middle53447
       High2922
      At least one study school was not identified as elementary or middle, but identified kindergarten through eighth grade or was not identified as middle or high, but identified as grades six through 12.
      Grade level5 and 101-31-5 or 61-33-51-5Kindergarten-6Kindergarten-1NR
      NR=not reported with specificity.
      NRKindergarten-1NR3-56-8KPrekindergarten-Kindergarten1-8Kindergarten-2Kindergarten-81-53-8Kindergarten-5Kindergarten-12
      Average percent wasted for dietary components measured
      In some cases, the average percent waste within a dietary component was reported within the cited article. In other cases, this study’s authors calculated average percent wasted within a dietary component when research design collected waste across multiple intervention periods. When percent consumed was reported (instead of percentage waste), this study’s authors calculated average percent waste by subtracting the percent consumed from 100% and, if necessary, averaged across multiple intervention periods or groups.
       Grains/bread21
      ◊=study indicated dietary component measured but not average percent wasted within dietary component.
      1835
       Vegetables511673516773
       Fruits/fruit juice301247334336
       Meat/meat alternate1818
       Milk98275254641
       Other32
      Measured waste of a mixed entrée.
      Measured waste of a mixed entrée.
      Specific macro- and/or micronutrients measured in whole meal.
      2
      Specific macro- and/or micronutrients measured in whole meal.
      Measured waste of a mixed entrée.
      Specific macro- and/or micronutrients measured in whole meal.
      18
      Measured waste of a mixed entrée.
      19
      Measured waste of a mixed entrée.
      51
      Measured waste of a mixed entrée.
      20
      Measured waste of a mixed entrée.
      Measured waste of a mixed entrée.
      27
      Measured waste of a mixed entrée.
      Days of food waste data collection
      Data calculated as number of days reported for study multiplied by number of schools involved in food waste collections.
      10NR338764736NRNR6089845165236484320
      No. of waste observations
      Data reported according to study as individual food items or entire student tray.
      130,00023013,749NR560294NR1,4141,933NR1,0603,0497933,0494733041,0302611802512,6382,027NR
      Effective public health practice project quality rating

      Effective Public Health Practice Project Quality Assessment Tool. http://www.ephpp.ca/tools.html. Accessed May 1, 2017.

      WeakWeakWeakModerateModerateWeakModerateModerateWeakWeakStrongModerateWeakModerateModerateWeakStrongStrongModerateModerateStrongStrongWeak
      a Data were collected to assess food waste after new school lunch meal patterns implemented beginning 2012.
      b Q=quasiexperimental.
      c CS=cross-sectional.
      d I=intervention.
      e Pre-post intervention.
      f Pre-post-follow-up intervention.
      g L=longitudnal.
      h MM=mixed methods.
      i RCT=randomized controlled trial.
      j DW=direct weighing.
      k Difference weight of plate waste for each food minus weight of average selected serving.
      l Percent plate waste calculated by dividing the weight of edible food waste by the mean serving weight.
      m Difference weight of plate waste for each food minus pre consumption selections for all students’ plates.
      n Weight of fluid milk remaining was determined using the full weight and empty container weight of the carton.
      o Fruit and vegetable consumption was calculated by weighing all produce prepared and subtracting unserved and waste weights, divided by number of students.
      p Waste was sorted by hand and weighed on a digital scale.
      q At least one study school was not identified as elementary or middle, but identified kindergarten through eighth grade or was not identified as middle or high, but identified as grades six through 12.
      r NR=not reported with specificity.
      s In some cases, the average percent waste within a dietary component was reported within the cited article. In other cases, this study’s authors calculated average percent wasted within a dietary component when research design collected waste across multiple intervention periods. When percent consumed was reported (instead of percentage waste), this study’s authors calculated average percent waste by subtracting the percent consumed from 100% and, if necessary, averaged across multiple intervention periods or groups.
      t ◊=study indicated dietary component measured but not average percent wasted within dietary component.
      u Measured waste of a mixed entrée.
      v Specific macro- and/or micronutrients measured in whole meal.
      w Data calculated as number of days reported for study multiplied by number of schools involved in food waste collections.
      x Data reported according to study as individual food items or entire student tray.
      Table 4Combination of methodologies for food waste studies conducted in the National School Lunch Program (visual estimation, digital photography, direct weighing)
      Data were collected to assess food waste after new school lunch meal patterns were implemented beginning 2012.
      Reference
      Comstock and colleagues, 1981
      • Comstock E.M.
      • St Pierre R.G.
      • Mackiernan Y.D.
      Measuring individual plate waste in school lunches: Visual estimation and children’s ratings vs. actual weighing of plate waste.
      Graves and colleagues, 1983
      • Graves K.
      • Shannon B.
      Using visual plate waste measurement to assess school lunch food behavior.
      Templeton and colleagues, 2005
      • Templeton S.B.
      • Marlette M.A.
      • Panemangalore M.
      Competitive foods increase the intake of energy and decrease the intake of certain nutrients by adolescents consuming school lunch.
      Wallen and colleagues, 2011
      • Wallen V.
      • Cunningham-Sabo L.
      • Auld G.
      • Romaniello C.
      Validation of a group-administered pictorial dietary recall with 9- to 11-year old children.
      Gase and colleagues, 2014
      • Gase L.N.
      • McCarthy W.J.
      • Robles B.
      • Kuo T.
      Student receptivity to new school meal offerings: Assessing fruit and vegetable waste among middle school students in the Los Angeles Unified School District.
      Hanks and colleagues, 2014
      • Hanks A.S.
      • Wansink B.
      • Just D.R.
      Reliability and accuracy of real-time visualization techniques for measuring school cafeteria tray waste: Validating the quarter-waste method.
      Taylor and colleagues, 2014
      • Taylor J.C.
      • Yon B.A.
      • Johnson R.K.
      Reliability and validity of digital imaging as a measure of school children’s fruit and vegetable consumption.
      Schwartz and colleagues, 2015
      • Schwartz M.B.
      • Henderson K.E.
      • Read M.
      • Danna N.
      • Ickovics J.R.
      New school regulations increase fruit consumption and do not increase total plate waste.
      Study designCS
      CS=cross-sectional.
      Cross-sectional study used for validation purposes.
      CS
      Cross-sectional study used for validation purposes.
      CSCS
      Cross-sectional study used for validation purposes.
      CSCS
      Cross-sectional study used for validation purposes.
      CS
      Cross-sectional study used for validation purposes.
      I
      I=intervention.
      Pre-post intervention.
      Specific data collection methodW
      W=direct weighing.


      VO
      VO=visual observation.
      W
      Difference weight of plate waste for each food minus weight of average selected serving.


      VO
      Quarter waste method (none, half, three-quarters, or all).
      W
      Difference weight of plate waste for each food minus weight of average selected serving.


      DP
      DP=digital photography.
      Estimate percent of food selected and plate waste in photograph compared with reference photograph or a sample tray.
      W
      Difference weight of plate waste for each food minus weight of average selected serving.


      VO
      Quarter waste method (none, half, three-quarters, or all).
      W

      VO
      Quarter waste method (none, half, three-quarters, or all).
      W

      VO
      Quarter waste method (none, half, three-quarters, or all).


      DP
      Estimate percent of food selected and plate waste in photograph compared with reference photograph or a sample tray.
      W
      Difference weight of plate waste for each food minus weight of average selected serving.


      DP
      Estimate percent of food selected and plate waste in photograph compared with reference photograph or a sample tray.
      W
      Difference weight of plate waste for each food minus weight of average selected serving.


      DP
      Type and no. of schools
       Elementary51212
       Middle3412
      Grade levelKindergarten-61-664NR
      NR=not reported with specificity.
      Kindergarten-53-55-7
      Average percent wasted for dietary components measured
      In some cases, the average percent waste within a dietary component was reported within the cited article. In other cases, this study’s authors calculated average percentage wasted within a dietary component when research design collected waste across multiple intervention periods. When percent consumed was reported (instead of percentage waste), this study’s authors calculated average percetage waste by subtracting the percentage consumed from 100% and, when necessary, averaged across multiple intervention periods or groups.
       Grains/bread
      ◊=Study indicated dietary component measured but not average percentage wasted within dietary component.
       Vegetables51
       Fruits/fruit juice31
       Meat/meat alternate
       Milk45
       Other
      Measured waste of a mixed entrée.
      Measured waste of a mixed entrée.
      Specific macro- and/or micronutrients measured in whole meal.
      Measured waste of a mixed entrée.
      Measured waste of a mixed entrée.
      Measured waste of a mixed entrée.
      26
      Measured waste of a mixed entrée.
      Days of food waste data collection
      Data calculated as number of days reported for study multiplied by number of schools involved in food waste collections.
      48241201836
      No. of waste observations
      Data reported according to study as individual food items or entire student tray.
      2,0004507431252,2281972761,340
      Effective public health practice project quality rating

      Effective Public Health Practice Project Quality Assessment Tool. http://www.ephpp.ca/tools.html. Accessed May 1, 2017.

      WeakWeakModerateModerateModerateModerateModerateModerate
      a Data were collected to assess food waste after new school lunch meal patterns were implemented beginning 2012.
      b CS=cross-sectional.
      c Cross-sectional study used for validation purposes.
      d I=intervention.
      e Pre-post intervention.
      f W=direct weighing.
      g VO=visual observation.
      h Difference weight of plate waste for each food minus weight of average selected serving.
      i Quarter waste method (none, half, three-quarters, or all).
      j DP=digital photography.
      k Estimate percent of food selected and plate waste in photograph compared with reference photograph or a sample tray.
      l NR=not reported with specificity.
      m In some cases, the average percent waste within a dietary component was reported within the cited article. In other cases, this study’s authors calculated average percentage wasted within a dietary component when research design collected waste across multiple intervention periods. When percent consumed was reported (instead of percentage waste), this study’s authors calculated average percetage waste by subtracting the percentage consumed from 100% and, when necessary, averaged across multiple intervention periods or groups.
      n ◊=Study indicated dietary component measured but not average percentage wasted within dietary component.
      o Measured waste of a mixed entrée.
      p Specific macro- and/or micronutrients measured in whole meal.
      q Data calculated as number of days reported for study multiplied by number of schools involved in food waste collections.
      r Data reported according to study as individual food items or entire student tray.

      In-Person Visual Estimation of Food Waste through Observation

      In-person visual estimation through observation of food waste occurred in 11 studies (Table 1).
      • Green N.R.
      • Munroe S.G.
      Evaluating nutrient-based nutrition education by nutrition knowledge and school lunch plate waste.
      • Reger C.
      • O’Neil C.E.
      • Nicklas T.A.
      • Myers L.
      • Berenson G.S.
      Plate waste of school lunches served to children in a low socioeconomic elementary school in South Louisiana.
      • Auld G.W.
      • Romaniello C.
      • Heimendinger J.
      • Hambidge C.
      • Hambidge M.
      Outcomes from a school-based nutrition education program alternating special resource teachers and classroom teachers.
      • Blom-Hoffman J.
      • Kelleher C.
      • Power T.J.
      • Leff S.S.
      Promoting healthy food consumption among young children: Evaluation of a multi-component nutrition education program.
      • Just D.
      • Price J.
      Default options, incentives and food choices: Evidence from elementary-school children.
      • Wansink B.
      • Just D.R.
      • Hanks A.S.
      • Smith L.E.
      Pre-sliced fruit in school cafeterias: Children’s selection and intake.
      • Just D.R.
      • Wansink B.
      • Hanks A.S.
      Chefs move to schools. A pilot examination of how chef-created dishes can increase school lunch participation and fruit and vegetable intake.
      • Cullen K.W.
      • Chen T.A.
      • Dave J.M.
      • Jensen H.
      Differential improvements in student fruit and vegetable consumption in response to the new National School Lunch Program regulations: A pilot study.
      • Cullen K.W.
      • Chen T.A.
      • Dave J.M.
      Changes in foods selected and consumed after implementation of the new National School Lunch Program meal patterns in southeast Texas.
      • Price J.
      • Just D.R.
      Lunch, recess and nutrition: Responding to time incentives in the cafeteria.
      • Wansink B.
      • Hanks A.S.
      • Just D.R.
      A plant to plate pilot: A cold-climate high school garden increased vegetable selection but also waste.
      Researchers conducted in-person visual estimation through observation by first viewing several serving sizes of school lunch foods of interest to understand the appearance of the average plated food component. Researchers then weighed several samples of the plated food item of interest to find the average serving weight in grams or ounces. Finally, student trays were collected and assessed for the amount of food wasted in validated increments. Increments included less or more than half wasted,
      • Green N.R.
      • Munroe S.G.
      Evaluating nutrient-based nutrition education by nutrition knowledge and school lunch plate waste.
      • Just D.
      • Price J.
      Default options, incentives and food choices: Evidence from elementary-school children.
      • Price J.
      • Just D.R.
      Lunch, recess and nutrition: Responding to time incentives in the cafeteria.
      quarters (eg, none, half, three-quarters, or all),
      • Wansink B.
      • Just D.R.
      • Hanks A.S.
      • Smith L.E.
      Pre-sliced fruit in school cafeterias: Children’s selection and intake.
      • Just D.R.
      • Wansink B.
      • Hanks A.S.
      Chefs move to schools. A pilot examination of how chef-created dishes can increase school lunch participation and fruit and vegetable intake.
      • Cullen K.W.
      • Chen T.A.
      • Dave J.M.
      • Jensen H.
      Differential improvements in student fruit and vegetable consumption in response to the new National School Lunch Program regulations: A pilot study.
      • Cullen K.W.
      • Chen T.A.
      • Dave J.M.
      Changes in foods selected and consumed after implementation of the new National School Lunch Program meal patterns in southeast Texas.
      • Wansink B.
      • Hanks A.S.
      • Just D.R.
      A plant to plate pilot: A cold-climate high school garden increased vegetable selection but also waste.
      or a 6-point scale (eg, 0=0% to 10% and 5=91% to 100%),
      • Reger C.
      • O’Neil C.E.
      • Nicklas T.A.
      • Myers L.
      • Berenson G.S.
      Plate waste of school lunches served to children in a low socioeconomic elementary school in South Louisiana.
      • Blom-Hoffman J.
      • Kelleher C.
      • Power T.J.
      • Leff S.S.
      Promoting healthy food consumption among young children: Evaluation of a multi-component nutrition education program.
      or a percent estimation (eg, on a scale of 0% to 100%).
      • Auld G.W.
      • Romaniello C.
      • Heimendinger J.
      • Hambidge C.
      • Hambidge M.
      Outcomes from a school-based nutrition education program alternating special resource teachers and classroom teachers.
      In some studies, a computer program was used to estimate the grams or ounces and energy of food consumed from the in-person visual estimation through observation.
      One study focused on the total amount of food wasted.
      • Reger C.
      • O’Neil C.E.
      • Nicklas T.A.
      • Myers L.
      • Berenson G.S.
      Plate waste of school lunches served to children in a low socioeconomic elementary school in South Louisiana.
      Other studies used food waste measurement as a proxy for the amount of foods students consumed. The research had a variety of aims, including to understand the influence of nutrition education
      • Green N.R.
      • Munroe S.G.
      Evaluating nutrient-based nutrition education by nutrition knowledge and school lunch plate waste.
      • Auld G.W.
      • Romaniello C.
      • Heimendinger J.
      • Hambidge C.
      • Hambidge M.
      Outcomes from a school-based nutrition education program alternating special resource teachers and classroom teachers.
      • Blom-Hoffman J.
      • Kelleher C.
      • Power T.J.
      • Leff S.S.
      Promoting healthy food consumption among young children: Evaluation of a multi-component nutrition education program.
      • Wansink B.
      • Hanks A.S.
      • Just D.R.
      A plant to plate pilot: A cold-climate high school garden increased vegetable selection but also waste.
      or changes in nutrition requirements.
      • Cullen K.W.
      • Chen T.A.
      • Dave J.M.
      • Jensen H.
      Differential improvements in student fruit and vegetable consumption in response to the new National School Lunch Program regulations: A pilot study.
      • Cullen K.W.
      • Chen T.A.
      • Dave J.M.
      Changes in foods selected and consumed after implementation of the new National School Lunch Program meal patterns in southeast Texas.
      In addition, studies examined the effects of lunchtime procedures or the food environment or infrastructure
      • Just D.
      • Price J.
      Default options, incentives and food choices: Evidence from elementary-school children.
      • Wansink B.
      • Just D.R.
      • Hanks A.S.
      • Smith L.E.
      Pre-sliced fruit in school cafeterias: Children’s selection and intake.
      • Price J.
      • Just D.R.
      Lunch, recess and nutrition: Responding to time incentives in the cafeteria.
      and food acceptability on consumption levels.
      • Just D.R.
      • Wansink B.
      • Hanks A.S.
      Chefs move to schools. A pilot examination of how chef-created dishes can increase school lunch participation and fruit and vegetable intake.
      Studies were concentrated in the West,
      • Just D.
      • Price J.
      Default options, incentives and food choices: Evidence from elementary-school children.
      • Price J.
      • Just D.R.
      Lunch, recess and nutrition: Responding to time incentives in the cafeteria.
      Northeast,
      • Blom-Hoffman J.
      • Kelleher C.
      • Power T.J.
      • Leff S.S.
      Promoting healthy food consumption among young children: Evaluation of a multi-component nutrition education program.
      • Wansink B.
      • Just D.R.
      • Hanks A.S.
      • Smith L.E.
      Pre-sliced fruit in school cafeterias: Children’s selection and intake.
      • Just D.R.
      • Wansink B.
      • Hanks A.S.
      Chefs move to schools. A pilot examination of how chef-created dishes can increase school lunch participation and fruit and vegetable intake.
      • Wansink B.
      • Hanks A.S.
      • Just D.R.
      A plant to plate pilot: A cold-climate high school garden increased vegetable selection but also waste.
      and South,
      • Reger C.
      • O’Neil C.E.
      • Nicklas T.A.
      • Myers L.
      • Berenson G.S.
      Plate waste of school lunches served to children in a low socioeconomic elementary school in South Louisiana.
      • Cullen K.W.
      • Chen T.A.
      • Dave J.M.
      • Jensen H.
      Differential improvements in student fruit and vegetable consumption in response to the new National School Lunch Program regulations: A pilot study.
      • Cullen K.W.
      • Chen T.A.
      • Dave J.M.
      Changes in foods selected and consumed after implementation of the new National School Lunch Program meal patterns in southeast Texas.
      with two studies not reporting geographic location.
      • Green N.R.
      • Munroe S.G.
      Evaluating nutrient-based nutrition education by nutrition knowledge and school lunch plate waste.
      • Auld G.W.
      • Romaniello C.
      • Heimendinger J.
      • Hambidge C.
      • Hambidge M.
      Outcomes from a school-based nutrition education program alternating special resource teachers and classroom teachers.
      Three studies examined schools with free and reduced lunch eligibility rates of more than 80%.
      • Reger C.
      • O’Neil C.E.
      • Nicklas T.A.
      • Myers L.
      • Berenson G.S.
      Plate waste of school lunches served to children in a low socioeconomic elementary school in South Louisiana.
      • Auld G.W.
      • Romaniello C.
      • Heimendinger J.
      • Hambidge C.
      • Hambidge M.
      Outcomes from a school-based nutrition education program alternating special resource teachers and classroom teachers.
      • Blom-Hoffman J.
      • Kelleher C.
      • Power T.J.
      • Leff S.S.
      Promoting healthy food consumption among young children: Evaluation of a multi-component nutrition education program.
      By far, fruits and vegetables were the most frequently studied food groups.
      • Reger C.
      • O’Neil C.E.
      • Nicklas T.A.
      • Myers L.
      • Berenson G.S.
      Plate waste of school lunches served to children in a low socioeconomic elementary school in South Louisiana.
      • Auld G.W.
      • Romaniello C.
      • Heimendinger J.
      • Hambidge C.
      • Hambidge M.
      Outcomes from a school-based nutrition education program alternating special resource teachers and classroom teachers.
      • Blom-Hoffman J.
      • Kelleher C.
      • Power T.J.
      • Leff S.S.
      Promoting healthy food consumption among young children: Evaluation of a multi-component nutrition education program.
      • Just D.
      • Price J.
      Default options, incentives and food choices: Evidence from elementary-school children.
      • Wansink B.
      • Just D.R.
      • Hanks A.S.
      • Smith L.E.
      Pre-sliced fruit in school cafeterias: Children’s selection and intake.
      • Just D.R.
      • Wansink B.
      • Hanks A.S.
      Chefs move to schools. A pilot examination of how chef-created dishes can increase school lunch participation and fruit and vegetable intake.
      • Cullen K.W.
      • Chen T.A.
      • Dave J.M.
      • Jensen H.
      Differential improvements in student fruit and vegetable consumption in response to the new National School Lunch Program regulations: A pilot study.
      • Cullen K.W.
      • Chen T.A.
      • Dave J.M.
      Changes in foods selected and consumed after implementation of the new National School Lunch Program meal patterns in southeast Texas.
      • Price J.
      • Just D.R.
      Lunch, recess and nutrition: Responding to time incentives in the cafeteria.
      • Wansink B.
      • Hanks A.S.
      • Just D.R.
      A plant to plate pilot: A cold-climate high school garden increased vegetable selection but also waste.
      Nutrition education was minimally effective in decreasing the amount of food waste.
      • Green N.R.
      • Munroe S.G.
      Evaluating nutrient-based nutrition education by nutrition knowledge and school lunch plate waste.
      • Auld G.W.
      • Romaniello C.
      • Heimendinger J.
      • Hambidge C.
      • Hambidge M.
      Outcomes from a school-based nutrition education program alternating special resource teachers and classroom teachers.
      • Blom-Hoffman J.
      • Kelleher C.
      • Power T.J.
      • Leff S.S.
      Promoting healthy food consumption among young children: Evaluation of a multi-component nutrition education program.
      • Wansink B.
      • Hanks A.S.
      • Just D.R.
      A plant to plate pilot: A cold-climate high school garden increased vegetable selection but also waste.
      Modifying lunchtime procedures or the food itself increased consumption of foods and decreased waste.
      • Just D.
      • Price J.
      Default options, incentives and food choices: Evidence from elementary-school children.
      • Wansink B.
      • Just D.R.
      • Hanks A.S.
      • Smith L.E.
      Pre-sliced fruit in school cafeterias: Children’s selection and intake.
      • Just D.R.
      • Wansink B.
      • Hanks A.S.
      Chefs move to schools. A pilot examination of how chef-created dishes can increase school lunch participation and fruit and vegetable intake.
      • Price J.
      • Just D.R.
      Lunch, recess and nutrition: Responding to time incentives in the cafeteria.
      New nutrition standards resulted in no significant differences in the percentage of fruits, vegetables, or whole grains consumed or wasted.
      • Cullen K.W.
      • Chen T.A.
      • Dave J.M.
      Changes in foods selected and consumed after implementation of the new National School Lunch Program meal patterns in southeast Texas.
      Sex and age significantly influenced waste in Reger’s study.
      • Reger C.
      • O’Neil C.E.
      • Nicklas T.A.
      • Myers L.
      • Berenson G.S.
      Plate waste of school lunches served to children in a low socioeconomic elementary school in South Louisiana.

      Visual Estimation of Food Waste through Digital Photography

      Visual estimation through digital photography was used in 11 studies (Table 2).
      • Marlette M.A.
      • Templeton S.B.
      • Panemangalore M.
      Food type, food preparation, and competitive food purchases impact school lunch plate waste by sixth-grade students.
      • Martin C.K.
      • Newton R.L.
      • Anton S.D.
      • et al.
      Measurement of children's food intake with digital photography and the effects of second servings upon food intake.
      • Martin C.K.
      • Thomson J.L.
      • LeBlanc M.M.
      • et al.
      Children in school cafeterias select foods containing more saturated fat and energy than the Institute of Medicine Recommendations.
      • Smith S.L.
      • Cunningham-Sabo L.
      Food choice, plate waste and nutrient intake of elementary- and middle-school students participating in the US National School Lunch Program.
      • Williamson D.A.
      • Han H.
      • Johnson W.D.
      • Martin C.K.
      • Newton R.L.
      Modification of the school cafeteria environment can impact childhood nutrition: Results from the Wise Mind and LA Health studies.
      • Bontrager Yoder A.B.
      • Liebhart J.L.
      • McCarty D.J.
      • et al.
      Farm to elementary school programming increases access to fruits and vegetables and increases their consumption among those with low intake.
      • Bontrager Yoder A.B.
      • Schoeller D.A.
      Fruits and vegetables displace, but do not decrease, total energy in school lunches.
      • Hubbard K.L.
      • Bandini L.G.
      • Folta C.
      • et al.
      Impact of a Smarter Lunchroom intervention on food selection and consumption among adolescents and young adults with intellectual and developmental disabilities in a residential school setting.
      • Alaimo K.
      • Carlson J.J.
      • Pfeiffer K.A.
      • et al.
      Project FIT: A school, community and social marketing intervention improves healthy eating among low-income elementary school children.
      • Bontrager Yoder A.B.
      • Foecke L.L.
      • Schoeller D.A.
      Factors affecting fruit and vegetable school lunch waste in Wisconsin elementary schools participating in Farm to School programs.
      • Monlezun D.J.
      • Ly D.
      • Rolfsen M.
      • et al.
      Digital photography assessment of 1,750 elementary and middle school student lunch meals demonstrates improved nutrition with increased exposure to hands-on cooking and gardening classes.
      Researchers conducted visual estimation of food waste through digital photography by photographing either or both reference serving sizes of the food component of interest, or the student’s selected food preconsumption. When taking photographs of the reference serving sizes, researchers generally calculated an average weight for the food component as well. Each student’s tray was then photographed at the tray return area (postconsumption). In reviewing the photographs, food consumption was estimated as a percentage of the reference serving size or student’s preconsumption selection. Food waste estimates were made as a raw percent
      • Marlette M.A.
      • Templeton S.B.
      • Panemangalore M.
      Food type, food preparation, and competitive food purchases impact school lunch plate waste by sixth-grade students.
      • Martin C.K.
      • Newton R.L.
      • Anton S.D.
      • et al.
      Measurement of children's food intake with digital photography and the effects of second servings upon food intake.
      • Martin C.K.
      • Thomson J.L.
      • LeBlanc M.M.
      • et al.
      Children in school cafeterias select foods containing more saturated fat and energy than the Institute of Medicine Recommendations.
      or in increments of 10%,
      • Smith S.L.
      • Cunningham-Sabo L.
      Food choice, plate waste and nutrient intake of elementary- and middle-school students participating in the US National School Lunch Program.
      • Williamson D.A.
      • Han H.
      • Johnson W.D.
      • Martin C.K.
      • Newton R.L.
      Modification of the school cafeteria environment can impact childhood nutrition: Results from the Wise Mind and LA Health studies.
      • Monlezun D.J.
      • Ly D.
      • Rolfsen M.
      • et al.
      Digital photography assessment of 1,750 elementary and middle school student lunch meals demonstrates improved nutrition with increased exposure to hands-on cooking and gardening classes.
      25%,
      • Bontrager Yoder A.B.
      • Liebhart J.L.
      • McCarty D.J.
      • et al.
      Farm to elementary school programming increases access to fruits and vegetables and increases their consumption among those with low intake.
      • Bontrager Yoder A.B.
      • Schoeller D.A.
      Fruits and vegetables displace, but do not decrease, total energy in school lunches.
      • Hubbard K.L.
      • Bandini L.G.
      • Folta C.
      • et al.
      Impact of a Smarter Lunchroom intervention on food selection and consumption among adolescents and young adults with intellectual and developmental disabilities in a residential school setting.
      • Alaimo K.
      • Carlson J.J.
      • Pfeiffer K.A.
      • et al.
      Project FIT: A school, community and social marketing intervention improves healthy eating among low-income elementary school children.
      • Bontrager Yoder A.B.
      • Foecke L.L.
      • Schoeller D.A.
      Factors affecting fruit and vegetable school lunch waste in Wisconsin elementary schools participating in Farm to School programs.
      or 0% to 10% to 25% to 50% to 100%.
      • Williamson D.A.
      • Han H.
      • Johnson W.D.
      • Martin C.K.
      • Newton R.L.
      Modification of the school cafeteria environment can impact childhood nutrition: Results from the Wise Mind and LA Health studies.
      • Bontrager Yoder A.B.
      • Liebhart J.L.
      • McCarty D.J.
      • et al.
      Farm to elementary school programming increases access to fruits and vegetables and increases their consumption among those with low intake.
      Computer applications were used to estimate the weight and energy of food consumed from the visual estimation through digital photography in studies using this method.
      The purposes of each study varied, with food waste measures aimed at primarily understanding the amount of food waste
      • Marlette M.A.
      • Templeton S.B.
      • Panemangalore M.
      Food type, food preparation, and competitive food purchases impact school lunch plate waste by sixth-grade students.
      • Bontrager Yoder A.B.
      • Foecke L.L.
      • Schoeller D.A.
      Factors affecting fruit and vegetable school lunch waste in Wisconsin elementary schools participating in Farm to School programs.
      and food consumption,
      • Smith S.L.
      • Cunningham-Sabo L.
      Food choice, plate waste and nutrient intake of elementary- and middle-school students participating in the US National School Lunch Program.
      • Bontrager Yoder A.B.
      • Liebhart J.L.
      • McCarty D.J.
      • et al.
      Farm to elementary school programming increases access to fruits and vegetables and increases their consumption among those with low intake.
      • Bontrager Yoder A.B.
      • Schoeller D.A.
      Fruits and vegetables displace, but do not decrease, total energy in school lunches.
      modification of food environment or lunchtime procedures,
      • Williamson D.A.
      • Han H.
      • Johnson W.D.
      • Martin C.K.
      • Newton R.L.
      Modification of the school cafeteria environment can impact childhood nutrition: Results from the Wise Mind and LA Health studies.
      • Hubbard K.L.
      • Bandini L.G.
      • Folta C.
      • et al.
      Impact of a Smarter Lunchroom intervention on food selection and consumption among adolescents and young adults with intellectual and developmental disabilities in a residential school setting.
      instrument validity,
      • Martin C.K.
      • Newton R.L.
      • Anton S.D.
      • et al.
      Measurement of children's food intake with digital photography and the effects of second servings upon food intake.
      compliance with nutrition recommendations,
      • Martin C.K.
      • Thomson J.L.
      • LeBlanc M.M.
      • et al.
      Children in school cafeterias select foods containing more saturated fat and energy than the Institute of Medicine Recommendations.
      and nutrition education.
      • Alaimo K.
      • Carlson J.J.
      • Pfeiffer K.A.
      • et al.
      Project FIT: A school, community and social marketing intervention improves healthy eating among low-income elementary school children.
      • Monlezun D.J.
      • Ly D.
      • Rolfsen M.
      • et al.
      Digital photography assessment of 1,750 elementary and middle school student lunch meals demonstrates improved nutrition with increased exposure to hands-on cooking and gardening classes.
      Studies were conducted in the West,
      • Smith S.L.
      • Cunningham-Sabo L.
      Food choice, plate waste and nutrient intake of elementary- and middle-school students participating in the US National School Lunch Program.
      • Williamson D.A.
      • Han H.
      • Johnson W.D.
      • Martin C.K.
      • Newton R.L.
      Modification of the school cafeteria environment can impact childhood nutrition: Results from the Wise Mind and LA Health studies.
      Midwest,
      • Bontrager Yoder A.B.
      • Liebhart J.L.
      • McCarty D.J.
      • et al.
      Farm to elementary school programming increases access to fruits and vegetables and increases their consumption among those with low intake.
      • Bontrager Yoder A.B.
      • Schoeller D.A.
      Fruits and vegetables displace, but do not decrease, total energy in school lunches.
      • Alaimo K.
      • Carlson J.J.
      • Pfeiffer K.A.
      • et al.
      Project FIT: A school, community and social marketing intervention improves healthy eating among low-income elementary school children.
      • Bontrager Yoder A.B.
      • Foecke L.L.
      • Schoeller D.A.
      Factors affecting fruit and vegetable school lunch waste in Wisconsin elementary schools participating in Farm to School programs.
      Northeast,
      • Hubbard K.L.
      • Bandini L.G.
      • Folta C.
      • et al.
      Impact of a Smarter Lunchroom intervention on food selection and consumption among adolescents and young adults with intellectual and developmental disabilities in a residential school setting.
      and South,
      • Marlette M.A.
      • Templeton S.B.
      • Panemangalore M.
      Food type, food preparation, and competitive food purchases impact school lunch plate waste by sixth-grade students.
      • Martin C.K.
      • Thomson J.L.
      • LeBlanc M.M.
      • et al.
      Children in school cafeterias select foods containing more saturated fat and energy than the Institute of Medicine Recommendations.
      • Monlezun D.J.
      • Ly D.
      • Rolfsen M.
      • et al.
      Digital photography assessment of 1,750 elementary and middle school student lunch meals demonstrates improved nutrition with increased exposure to hands-on cooking and gardening classes.
      although one did not report geographic location.
      • Martin C.K.
      • Newton R.L.
      • Anton S.D.
      • et al.
      Measurement of children's food intake with digital photography and the effects of second servings upon food intake.
      Alaimo and colleagues
      • Alaimo K.
      • Carlson J.J.
      • Pfeiffer K.A.
      • et al.
      Project FIT: A school, community and social marketing intervention improves healthy eating among low-income elementary school children.
      and Monlezun and colleagues
      • Monlezun D.J.
      • Ly D.
      • Rolfsen M.
      • et al.
      Digital photography assessment of 1,750 elementary and middle school student lunch meals demonstrates improved nutrition with increased exposure to hands-on cooking and gardening classes.
      reported free and reduced rates near 100%, whereas several other studies did not report free and reduced rates.
      As in the studies using visual estimation techniques to measure waste, studies using digital photography also focused predominantly on fruits and vegetables. Several distinguished between forms of fruits and vegetables, such as cooked, raw, canned, and fresh.
      • Smith S.L.
      • Cunningham-Sabo L.
      Food choice, plate waste and nutrient intake of elementary- and middle-school students participating in the US National School Lunch Program.
      • Hubbard K.L.
      • Bandini L.G.
      • Folta C.
      • et al.
      Impact of a Smarter Lunchroom intervention on food selection and consumption among adolescents and young adults with intellectual and developmental disabilities in a residential school setting.
      • Bontrager Yoder A.B.
      • Foecke L.L.
      • Schoeller D.A.
      Factors affecting fruit and vegetable school lunch waste in Wisconsin elementary schools participating in Farm to School programs.
      Two studies reported that waste of fruit and vegetables was the highest when compared with other dietary components.
      • Marlette M.A.
      • Templeton S.B.
      • Panemangalore M.
      Food type, food preparation, and competitive food purchases impact school lunch plate waste by sixth-grade students.
      • Martin C.K.
      • Thomson J.L.
      • LeBlanc M.M.
      • et al.
      Children in school cafeterias select foods containing more saturated fat and energy than the Institute of Medicine Recommendations.
      Three studies reported a decrease in waste of fruit and vegetables and other dietary components as a result of an intervention.
      • Smith S.L.
      • Cunningham-Sabo L.
      Food choice, plate waste and nutrient intake of elementary- and middle-school students participating in the US National School Lunch Program.
      • Bontrager Yoder A.B.
      • Liebhart J.L.
      • McCarty D.J.
      • et al.
      Farm to elementary school programming increases access to fruits and vegetables and increases their consumption among those with low intake.
      • Hubbard K.L.
      • Bandini L.G.
      • Folta C.
      • et al.
      Impact of a Smarter Lunchroom intervention on food selection and consumption among adolescents and young adults with intellectual and developmental disabilities in a residential school setting.
      Several studies expressed food waste in terms of calories rather than as a percentage of food wasted.
      • Williamson D.A.
      • Han H.
      • Johnson W.D.
      • Martin C.K.
      • Newton R.L.
      Modification of the school cafeteria environment can impact childhood nutrition: Results from the Wise Mind and LA Health studies.
      • Bontrager Yoder A.B.
      • Schoeller D.A.
      Fruits and vegetables displace, but do not decrease, total energy in school lunches.
      • Monlezun D.J.
      • Ly D.
      • Rolfsen M.
      • et al.
      Digital photography assessment of 1,750 elementary and middle school student lunch meals demonstrates improved nutrition with increased exposure to hands-on cooking and gardening classes.

      Direct Weighing of Food Waste

      Direct weighing of food waste was used as the main research method in 23 studies (Table 3).
      • Byker C.J.
      • Farris A.R.
      • Marcenelle M.
      • Davis G.C.
      • Serrano E.L.
      Food waste in a school nutrition program after implementation of new lunch program guidelines.
      • Jansen G.R.
      • Harper J.M.
      Consumption and plate waste of menu items served in the National School Lunch Program.
      • Davidson F.R.R.
      Critical factors for school lunch acceptance in Washington, D.C.
      • Comstock E.M.
      • Symington L.E.
      Distributions of serving sizes and plate waste in school lunches: Implications for measurement.
      • Getlinger M.J.
      • Laughlin V.T.
      • Bell E.
      • Akre C.
      • Arjmandi B.H.
      Food waste is reduced when elementary-school children have recess before lunch.
      • Whatley J.E.
      • Donnelly J.E.
      • Jacobsen D.J.
      • Hill J.O.
      • Carlson M.K.
      Energy and macronutrient consumption of elementary school children served modified lower fat and sodium lunches or standard higher fat and sodium lunches.
      • Adams M.A.
      • Pelletier R.L.
      • Zive M.M.
      • Sallis J.F.
      Salad bars and fruit and vegetable consumption in elementary schools: A plate waste study.
      • Toma A.
      • Omary M.B.
      • Marquart L.F.
      • et al.
      Children’s acceptance, nutritional, and instrumental evaluations of whole grain and soluble fiber enriched foods.
      • Hoffman J.A.
      • Franko D.L.
      • Thompson D.R.
      • Power T.J.
      • Stallings V.A.
      Longitudinal behavioral effects of a school-based fruit and vegetable promotion program.
      • Lazor K.
      • Chapman N.
      • Levine E.
      Soy goes to school: Acceptance of healthful, vegetarian options in Maryland middle school lunches.
      • Chu L.
      • Warren C.A.
      • Sceets C.E.
      • et al.
      Acceptance of two US Department of Agriculture commodity whole-grain products: A school-based study in Texas and Minnesota.
      • Hoffman J.A.
      • Thompson D.R.
      • Franko D.L.
      • et al.
      Decaying behavioral effects in a randomized, multi-year fruit and vegetable intake intervention.
      • Cohen J.F.W.
      • Smit L.A.
      • Parker E.
      • et al.
      Long-term impact of a chef on school lunch consumption: Findings from a 2-Year pilot study in Boston middle schools.
      • Yon B.A.
      • Johnson R.K.
      • Stickle T.R.
      School children’s consumption of lower-calorie flavored milk: A plate waste study.
      • Cohen J.F.W.
      • Richardson S.
      • Austin S.B.
      • Economos C.D.
      • Rimm E.B.
      School lunch waste among middle school students: Nutrients consumed and costs.
      • Ramsay S.
      • Safaii S.
      • Croschere T.
      • Branen L.J.
      • Weist M.
      Kindergarteners’ entrée intake increases when served a larger entrée portion in school lunch: A quasi-experiment.
      • Cohen J.F.W.
      • Richardson S.
      • Parker E.
      • Catalano P.J.
      • Rimm E.B.
      Impact of the new US Department of Agriculture school meals standards on food selection, consumption and waste.
      • Hunsberger M.
      • McGinnis P.
      • Smith J.
      • Beamer B.A.
      • O’Malley J.
      Elementary school children’s recess schedule and dietary intake at lunch: A community-based participatory research partnership pilot study.
      • Jones B.A.
      • Madden G.J.
      • Wengreen H.J.
      • Aguilar S.S.
      • Desjardins E.A.
      Gamification of dietary decision-making in an elementary-school cafeteria.
      • Jones B.A.
      • Madden G.J.
      • Wengreen H.J.
      The FIT Game: Preliminary evaluation of a gamification approach to increasing fruit and vegetable consumption in school.
      • Cohen J.F.W.
      • Richardson S.A.
      • Cluggish S.A.
      • et al.
      Effects of choice architecture and chef-enhanced meals on the selection and consumption of healthier school foods: A randomized clinical trial.
      • Miller N.
      • Reicks M.
      • Redden J.P.
      • et al.
      Increasing portion sizes of fruits and vegetables in an elementary school lunch program can increase fruit and vegetable consumption.
      • Wilke A.C.
      • Graunke R.E.
      • Cornejo C.
      Food waste auditing at three Florida schools.
      The process for direct weighing of food waste generally includes to determine what is being served in the cafeteria on the day of the study, to determine which food(s) will be included in the study, to weigh random samples of the food(s) and calculate an average weight, to collect and weigh food waste from student trays, to calculate percent or grams or ounces consumed by subtracting the food waste collected in Step 4 from the average weight determined in Step 3 and multiplying by 100. Some research measured waste for all foods on the tray,
      • Byker C.J.
      • Farris A.R.
      • Marcenelle M.
      • Davis G.C.
      • Serrano E.L.
      Food waste in a school nutrition program after implementation of new lunch program guidelines.
      • Jansen G.R.
      • Harper J.M.
      Consumption and plate waste of menu items served in the National School Lunch Program.
      • Davidson F.R.R.
      Critical factors for school lunch acceptance in Washington, D.C.
      • Comstock E.M.
      • Symington L.E.
      Distributions of serving sizes and plate waste in school lunches: Implications for measurement.
      • Getlinger M.J.
      • Laughlin V.T.
      • Bell E.
      • Akre C.
      • Arjmandi B.H.
      Food waste is reduced when elementary-school children have recess before lunch.
      • Cohen J.F.W.
      • Smit L.A.
      • Parker E.
      • et al.
      Long-term impact of a chef on school lunch consumption: Findings from a 2-Year pilot study in Boston middle schools.
      • Cohen J.F.W.
      • Richardson S.
      • Austin S.B.
      • Economos C.D.
      • Rimm E.B.
      School lunch waste among middle school students: Nutrients consumed and costs.
      • Ramsay S.
      • Safaii S.
      • Croschere T.
      • Branen L.J.
      • Weist M.
      Kindergarteners’ entrée intake increases when served a larger entrée portion in school lunch: A quasi-experiment.
      • Cohen J.F.W.
      • Richardson S.
      • Parker E.
      • Catalano P.J.
      • Rimm E.B.
      Impact of the new US Department of Agriculture school meals standards on food selection, consumption and waste.
      • Hunsberger M.
      • McGinnis P.
      • Smith J.
      • Beamer B.A.
      • O’Malley J.
      Elementary school children’s recess schedule and dietary intake at lunch: A community-based participatory research partnership pilot study.
      • Miller N.
      • Reicks M.
      • Redden J.P.
      • et al.
      Increasing portion sizes of fruits and vegetables in an elementary school lunch program can increase fruit and vegetable consumption.
      • Wilke A.C.
      • Graunke R.E.
      • Cornejo C.
      Food waste auditing at three Florida schools.
      whereas others focused on collecting waste data about specific foods or food components.
      • Whatley J.E.
      • Donnelly J.E.
      • Jacobsen D.J.
      • Hill J.O.
      • Carlson M.K.
      Energy and macronutrient consumption of elementary school children served modified lower fat and sodium lunches or standard higher fat and sodium lunches.
      • Toma A.
      • Omary M.B.
      • Marquart L.F.
      • et al.
      Children’s acceptance, nutritional, and instrumental evaluations of whole grain and soluble fiber enriched foods.
      • Hoffman J.A.
      • Franko D.L.
      • Thompson D.R.
      • Power T.J.
      • Stallings V.A.
      Longitudinal behavioral effects of a school-based fruit and vegetable promotion program.
      • Lazor K.
      • Chapman N.
      • Levine E.
      Soy goes to school: Acceptance of healthful, vegetarian options in Maryland middle school lunches.
      • Chu L.
      • Warren C.A.
      • Sceets C.E.
      • et al.
      Acceptance of two US Department of Agriculture commodity whole-grain products: A school-based study in Texas and Minnesota.
      • Hoffman J.A.
      • Thompson D.R.
      • Franko D.L.
      • et al.
      Decaying behavioral effects in a randomized, multi-year fruit and vegetable intake intervention.
      • Yon B.A.
      • Johnson R.K.
      • Stickle T.R.
      School children’s consumption of lower-calorie flavored milk: A plate waste study.
      • Jones B.A.
      • Madden G.J.
      • Wengreen H.J.
      • Aguilar S.S.
      • Desjardins E.A.
      Gamification of dietary decision-making in an elementary-school cafeteria.
      • Jones B.A.
      • Madden G.J.
      • Wengreen H.J.
      The FIT Game: Preliminary evaluation of a gamification approach to increasing fruit and vegetable consumption in school.
      • Cohen J.F.W.
      • Richardson S.A.
      • Cluggish S.A.
      • et al.
      Effects of choice architecture and chef-enhanced meals on the selection and consumption of healthier school foods: A randomized clinical trial.
      Three additional studies measured the weight of all food before it was served, collected all food waste from student trays, and subtracted the total amount leftover.
      • Adams M.A.
      • Pelletier R.L.
      • Zive M.M.
      • Sallis J.F.
      Salad bars and fruit and vegetable consumption in elementary schools: A plate waste study.
      • Jones B.A.
      • Madden G.J.
      • Wengreen H.J.
      • Aguilar S.S.
      • Desjardins E.A.
      Gamification of dietary decision-making in an elementary-school cafeteria.
      • Jones B.A.
      • Madden G.J.
      • Wengreen H.J.
      The FIT Game: Preliminary evaluation of a gamification approach to increasing fruit and vegetable consumption in school.
      About three-fourths of studies used food waste as a proxy for understanding the amount of food students consumed.
      Research aimed to understand the impacts of nutrition education,
      • Hoffman J.A.
      • Franko D.L.
      • Thompson D.R.
      • Power T.J.
      • Stallings V.A.
      Longitudinal behavioral effects of a school-based fruit and vegetable promotion program.
      • Hoffman J.A.
      • Thompson D.R.
      • Franko D.L.
      • et al.
      Decaying behavioral effects in a randomized, multi-year fruit and vegetable intake intervention.
      • Jones B.A.
      • Madden G.J.
      • Wengreen H.J.
      • Aguilar S.S.
      • Desjardins E.A.
      Gamification of dietary decision-making in an elementary-school cafeteria.
      • Jones B.A.
      • Madden G.J.
      • Wengreen H.J.
      The FIT Game: Preliminary evaluation of a gamification approach to increasing fruit and vegetable consumption in school.
      changes in nutrition requirements,
      • Ramsay S.
      • Safaii S.
      • Croschere T.
      • Branen L.J.
      • Weist M.
      Kindergarteners’ entrée intake increases when served a larger entrée portion in school lunch: A quasi-experiment.
      lunchtime procedures or the food environment,
      • Getlinger M.J.
      • Laughlin V.T.
      • Bell E.
      • Akre C.
      • Arjmandi B.H.
      Food waste is reduced when elementary-school children have recess before lunch.
      • Adams M.A.
      • Pelletier R.L.
      • Zive M.M.
      • Sallis J.F.
      Salad bars and fruit and vegetable consumption in elementary schools: A plate waste study.
      • Hunsberger M.
      • McGinnis P.
      • Smith J.
      • Beamer B.A.
      • O’Malley J.
      Elementary school children’s recess schedule and dietary intake at lunch: A community-based participatory research partnership pilot study.
      • Cohen J.F.W.
      • Richardson S.A.
      • Cluggish S.A.
      • et al.
      Effects of choice architecture and chef-enhanced meals on the selection and consumption of healthier school foods: A randomized clinical trial.
      or food acceptability on consumption levels.
      • Whatley J.E.
      • Donnelly J.E.
      • Jacobsen D.J.
      • Hill J.O.
      • Carlson M.K.
      Energy and macronutrient consumption of elementary school children served modified lower fat and sodium lunches or standard higher fat and sodium lunches.
      • Toma A.
      • Omary M.B.
      • Marquart L.F.
      • et al.
      Children’s acceptance, nutritional, and instrumental evaluations of whole grain and soluble fiber enriched foods.
      • Lazor K.
      • Chapman N.
      • Levine E.
      Soy goes to school: Acceptance of healthful, vegetarian options in Maryland middle school lunches.
      • Chu L.
      • Warren C.A.
      • Sceets C.E.
      • et al.
      Acceptance of two US Department of Agriculture commodity whole-grain products: A school-based study in Texas and Minnesota.
      • Cohen J.F.W.
      • Smit L.A.
      • Parker E.
      • et al.
      Long-term impact of a chef on school lunch consumption: Findings from a 2-Year pilot study in Boston middle schools.
      • Yon B.A.
      • Johnson R.K.
      • Stickle T.R.
      School children’s consumption of lower-calorie flavored milk: A plate waste study.
      • Cohen J.F.W.
      • Richardson S.A.
      • Cluggish S.A.
      • et al.
      Effects of choice architecture and chef-enhanced meals on the selection and consumption of healthier school foods: A randomized clinical trial.
      • Miller N.
      • Reicks M.
      • Redden J.P.
      • et al.
      Increasing portion sizes of fruits and vegetables in an elementary school lunch program can increase fruit and vegetable consumption.
      Six studies specifically aimed to directly measure the amount of waste produced in the NSLP.
      • Byker C.J.
      • Farris A.R.
      • Marcenelle M.
      • Davis G.C.
      • Serrano E.L.
      Food waste in a school nutrition program after implementation of new lunch program guidelines.
      • Jansen G.R.
      • Harper J.M.
      Consumption and plate waste of menu items served in the National School Lunch Program.
      • Davidson F.R.R.
      Critical factors for school lunch acceptance in Washington, D.C.
      • Comstock E.M.
      • Symington L.E.
      Distributions of serving sizes and plate waste in school lunches: Implications for measurement.
      • Cohen J.F.W.
      • Richardson S.
      • Austin S.B.
      • Economos C.D.
      • Rimm E.B.
      School lunch waste among middle school students: Nutrients consumed and costs.
      • Cohen J.F.W.
      • Richardson S.
      • Parker E.
      • Catalano P.J.
      • Rimm E.B.
      Impact of the new US Department of Agriculture school meals standards on food selection, consumption and waste.
      • Wilke A.C.
      • Graunke R.E.
      • Cornejo C.
      Food waste auditing at three Florida schools.
      Studies were concentrated in the West,
      • Adams M.A.
      • Pelletier R.L.
      • Zive M.M.
      • Sallis J.F.
      Salad bars and fruit and vegetable consumption in elementary schools: A plate waste study.
      • Toma A.
      • Omary M.B.
      • Marquart L.F.
      • et al.
      Children’s acceptance, nutritional, and instrumental evaluations of whole grain and soluble fiber enriched foods.
      • Hunsberger M.
      • McGinnis P.
      • Smith J.
      • Beamer B.A.
      • O’Malley J.
      Elementary school children’s recess schedule and dietary intake at lunch: A community-based participatory research partnership pilot study.
      • Jones B.A.
      • Madden G.J.
      • Wengreen H.J.
      • Aguilar S.S.
      • Desjardins E.A.
      Gamification of dietary decision-making in an elementary-school cafeteria.
      • Jones B.A.
      • Madden G.J.
      • Wengreen H.J.
      The FIT Game: Preliminary evaluation of a gamification approach to increasing fruit and vegetable consumption in school.
      Midwest,
      • Getlinger M.J.
      • Laughlin V.T.
      • Bell E.
      • Akre C.
      • Arjmandi B.H.
      Food waste is reduced when elementary-school children have recess before lunch.
      • Chu L.
      • Warren C.A.
      • Sceets C.E.
      • et al.
      Acceptance of two US Department of Agriculture commodity whole-grain products: A school-based study in Texas and Minnesota.
      • Miller N.
      • Reicks M.
      • Redden J.P.
      • et al.
      Increasing portion sizes of fruits and vegetables in an elementary school lunch program can increase fruit and vegetable consumption.
      Northeast,
      • Hoffman J.A.
      • Franko D.L.
      • Thompson D.R.
      • Power T.J.
      • Stallings V.A.
      Longitudinal behavioral effects of a school-based fruit and vegetable promotion program.
      • Hoffman J.A.
      • Thompson D.R.
      • Franko D.L.
      • et al.
      Decaying behavioral effects in a randomized, multi-year fruit and vegetable intake intervention.
      • Cohen J.F.W.
      • Smit L.A.
      • Parker E.
      • et al.
      Long-term impact of a chef on school lunch consumption: Findings from a 2-Year pilot study in Boston middle schools.
      • Cohen J.F.W.
      • Richardson S.
      • Austin S.B.
      • Economos C.D.
      • Rimm E.B.
      School lunch waste among middle school students: Nutrients consumed and costs.
      • Cohen J.F.W.
      • Richardson S.
      • Parker E.
      • Catalano P.J.
      • Rimm E.B.
      Impact of the new US Department of Agriculture school meals standards on food selection, consumption and waste.
      • Cohen J.F.W.
      • Richardson S.A.
      • Cluggish S.A.
      • et al.
      Effects of choice architecture and chef-enhanced meals on the selection and consumption of healthier school foods: A randomized clinical trial.
      South,
      • Byker C.J.
      • Farris A.R.
      • Marcenelle M.
      • Davis G.C.
      • Serrano E.L.
      Food waste in a school nutrition program after implementation of new lunch program guidelines.
      • Davidson F.R.R.
      Critical factors for school lunch acceptance in Washington, D.C.
      • Monlezun D.J.
      • Ly D.
      • Rolfsen M.
      • et al.
      Digital photography assessment of 1,750 elementary and middle school student lunch meals demonstrates improved nutrition with increased exposure to hands-on cooking and gardening classes.
      • Wilke A.C.
      • Graunke R.E.
      • Cornejo C.
      Food waste auditing at three Florida schools.
      and mixed locations,
      • Jansen G.R.
      • Harper J.M.
      Consumption and plate waste of menu items served in the National School Lunch Program.
      • Comstock E.M.
      • Symington L.E.
      Distributions of serving sizes and plate waste in school lunches: Implications for measurement.
      • Lazor K.
      • Chapman N.
      • Levine E.
      Soy goes to school: Acceptance of healthful, vegetarian options in Maryland middle school lunches.
      • Yon B.A.
      • Johnson R.K.
      • Stickle T.R.
      School children’s consumption of lower-calorie flavored milk: A plate waste study.
      with two studies not reporting geographic location.
      • Whatley J.E.
      • Donnelly J.E.
      • Jacobsen D.J.
      • Hill J.O.
      • Carlson M.K.
      Energy and macronutrient consumption of elementary school children served modified lower fat and sodium lunches or standard higher fat and sodium lunches.
      • Ramsay S.
      • Safaii S.
      • Croschere T.
      • Branen L.J.
      • Weist M.
      Kindergarteners’ entrée intake increases when served a larger entrée portion in school lunch: A quasi-experiment.
      Seven studies reported free and reduced lunch eligibility rates above 80%.
      • Chu L.
      • Warren C.A.
      • Sceets C.E.
      • et al.
      Acceptance of two US Department of Agriculture commodity whole-grain products: A school-based study in Texas and Minnesota.
      • Hoffman J.A.
      • Thompson D.R.
      • Franko D.L.
      • et al.
      Decaying behavioral effects in a randomized, multi-year fruit and vegetable intake intervention.
      • Cohen J.F.W.
      • Smit L.A.
      • Parker E.
      • et al.
      Long-term impact of a chef on school lunch consumption: Findings from a 2-Year pilot study in Boston middle schools.
      • Cohen J.F.W.
      • Richardson S.
      • Austin S.B.
      • Economos C.D.
      • Rimm E.B.
      School lunch waste among middle school students: Nutrients consumed and costs.
      • Cohen J.F.W.
      • Richardson S.
      • Parker E.
      • Catalano P.J.
      • Rimm E.B.
      Impact of the new US Department of Agriculture school meals standards on food selection, consumption and waste.
      • Hunsberger M.
      • McGinnis P.
      • Smith J.
      • Beamer B.A.
      • O’Malley J.
      Elementary school children’s recess schedule and dietary intake at lunch: A community-based participatory research partnership pilot study.
      • Cohen J.F.W.
      • Richardson S.A.
      • Cluggish S.A.
      • et al.
      Effects of choice architecture and chef-enhanced meals on the selection and consumption of healthier school foods: A randomized clinical trial.
      The most common food components examined in studies involving direct weighing were fruits and vegetables. Sixteen studies reported the quantity of waste from fruits and vegetables. Other dietary components examined included milk, grains, and high-protein items such as soy-based products. Studies examined acceptance of specific foods in the cafeteria, such as whole grains.
      • Adams M.A.
      • Pelletier R.L.
      • Zive M.M.
      • Sallis J.F.
      Salad bars and fruit and vegetable consumption in elementary schools: A plate waste study.
      • Toma A.
      • Omary M.B.
      • Marquart L.F.
      • et al.
      Children’s acceptance, nutritional, and instrumental evaluations of whole grain and soluble fiber enriched foods.
      • Lazor K.
      • Chapman N.
      • Levine E.
      Soy goes to school: Acceptance of healthful, vegetarian options in Maryland middle school lunches.
      • Chu L.
      • Warren C.A.
      • Sceets C.E.
      • et al.
      Acceptance of two US Department of Agriculture commodity whole-grain products: A school-based study in Texas and Minnesota.
      • Yon B.A.
      • Johnson R.K.
      • Stickle T.R.
      School children’s consumption of lower-calorie flavored milk: A plate waste study.
      Two studies found a reduction in food waste from changing recess to before lunch.
      • Getlinger M.J.
      • Laughlin V.T.
      • Bell E.
      • Akre C.
      • Arjmandi B.H.
      Food waste is reduced when elementary-school children have recess before lunch.
      • Hunsberger M.
      • McGinnis P.
      • Smith J.
      • Beamer B.A.
      • O’Malley J.
      Elementary school children’s recess schedule and dietary intake at lunch: A community-based participatory research partnership pilot study.
      Many interventions (eg, nutrition education, changes in nutrition requirements, lunchtime procedures or the food environment, or food acceptability on consumption levels) led to a decrease in waste for some foods.

      Combination of Methods

      Eight studies used a combination of in-person visual estimation through observation, visual estimation through digital photography, and/or direct weighing methods (Table 4).
      • Comstock E.M.
      • St Pierre R.G.
      • Mackiernan Y.D.
      Measuring individual plate waste in school lunches: Visual estimation and children’s ratings vs. actual weighing of plate waste.
      • Graves K.
      • Shannon B.
      Using visual plate waste measurement to assess school lunch food behavior.
      • Templeton S.B.
      • Marlette M.A.
      • Panemangalore M.
      Competitive foods increase the intake of energy and decrease the intake of certain nutrients by adolescents consuming school lunch.
      • Wallen V.
      • Cunningham-Sabo L.
      • Auld G.
      • Romaniello C.
      Validation of a group-administered pictorial dietary recall with 9- to 11-year old children.
      • Gase L.N.
      • McCarthy W.J.
      • Robles B.
      • Kuo T.
      Student receptivity to new school meal offerings: Assessing fruit and vegetable waste among middle school students in the Los Angeles Unified School District.
      • Hanks A.S.
      • Wansink B.
      • Just D.R.
      Reliability and accuracy of real-time visualization techniques for measuring school cafeteria tray waste: Validating the quarter-waste method.
      • Taylor J.C.
      • Yon B.A.
      • Johnson R.K.
      Reliability and validity of digital imaging as a measure of school children’s fruit and vegetable consumption.
      • Schwartz M.B.
      • Henderson K.E.
      • Read M.
      • Danna N.
      • Ickovics J.R.
      New school regulations increase fruit consumption and do not increase total plate waste.
      One study used direct weighing, visual observation, and children’s ratings.
      • Comstock E.M.
      • St Pierre R.G.
      • Mackiernan Y.D.
      Measuring individual plate waste in school lunches: Visual estimation and children’s ratings vs. actual weighing of plate waste.
      Three studies used direct weighing and visual observation.
      • Graves K.
      • Shannon B.
      Using visual plate waste measurement to assess school lunch food behavior.
      • Wallen V.
      • Cunningham-Sabo L.
      • Auld G.
      • Romaniello C.
      Validation of a group-administered pictorial dietary recall with 9- to 11-year old children.
      • Gase L.N.
      • McCarthy W.J.
      • Robles B.
      • Kuo T.
      Student receptivity to new school meal offerings: Assessing fruit and vegetable waste among middle school students in the Los Angeles Unified School District.
      Three studies used direct weighing and digital photography.
      • Templeton S.B.
      • Marlette M.A.
      • Panemangalore M.
      Competitive foods increase the intake of energy and decrease the intake of certain nutrients by adolescents consuming school lunch.
      • Taylor J.C.
      • Yon B.A.
      • Johnson R.K.
      Reliability and validity of digital imaging as a measure of school children’s fruit and vegetable consumption.
      • Schwartz M.B.
      • Henderson K.E.
      • Read M.
      • Danna N.
      • Ickovics J.R.
      New school regulations increase fruit consumption and do not increase total plate waste.
      One study used direct weighing, two types of visual observation, and visual photography.
      • Hanks A.S.
      • Wansink B.
      • Just D.R.
      Reliability and accuracy of real-time visualization techniques for measuring school cafeteria tray waste: Validating the quarter-waste method.
      Four studies were designed to validate or compare food waste measures,
      • Comstock E.M.
      • St Pierre R.G.
      • Mackiernan Y.D.
      Measuring individual plate waste in school lunches: Visual estimation and children’s ratings vs. actual weighing of plate waste.
      • Graves K.
      • Shannon B.
      Using visual plate waste measurement to assess school lunch food behavior.
      • Hanks A.S.
      • Wansink B.
      • Just D.R.
      Reliability and accuracy o