We appreciate the interest in our article and believe that the authors of the letter to the Editor raise some interesting points. We have responded to the main points below.
The letter authors raise the issue of whether or not indexes designed to capture overall diet quality are appropriate for assessing single meal/eating occasions. We agree that this is an important issue to consider and address this topic in several sections of the article. For example, in the discussion section, we state that “traditionally…[the Healthy Eating Index (HEI)] has been used to analyze overall diet quality for populations and food environments and not for individual meals. Therefore, some of the components may not translate well to assessing the quality of a single meal.”
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For these reasons, one could conclude, as the letter authors do, that HEI and other dietary indexes should not be used to define single meal healthfulness. Perhaps this is true for how they are currently designed, but we maintain, as we mention in the introduction to the article, that it is important to consider the healthfulness of “single meal/eating occasions” as well as overall diet quality.1
This could be done by using or adapting existing indexes, and our research provides an important starting point for how indexes could be modified or created to assess the healthfulness of meals.In addition, it is important to note that two of the four indexes we analyzed for the study were designed or can be used to assess the healthfulness of meals (Main Meal Quality Index [MMQI] and Nutrient Rich Foods).
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,3
Despite this, the letter authors suggest that the MMQI may not have been appropriate to assess a midday cafeteria meal because the MMQI was designed to assess the main meal of the day. However, there have been recommendations in the popular press and in research studies in recent years to make lunch/the midday meal the main meal of the day,4
, 5
, - Bruso J.
What should be your biggest meal?.
2019
https://www.livestrong.com/article/469196-what-should-be-your-biggest-meal/
Date accessed: July 25, 2022
6
, - Gomez A.
This is when you should eat your lightest and heaviest meals of the Day.
https://www.womenshealthmag.com/weight-loss/a19967168/lightest-meal-of-the-day/
Date: 2017
Date accessed: July 25, 2022
7
and people of different cultures have different traditions as to when the main meal of the day should occur. As a result of these factors and the diversity of our study population, it may not be correct to assume that we “did not choose the day’s main meal” as the letter authors do.When using or adapting existing diet indexes to measure single meals it would be important, as the authors of the letter describe, to consider the potential for an individual to be “penalized” if they do not choose certain food groups for a specific eating occasion. The authors state, “if a person consumes fruit in the recommended amount during a morning meal, they should not be penalized for this eating pattern if their lunch food choices exclude fruit. Yet this is effectively what the single meal-focused analysis did.” We also thought about this potential issue and did mention in the article that “components of the HEI-2015 that received the lowest average scores included Total Fruit (0.95 out of 5), Whole Fruit (1.02 out of 5),…”.
1
It may indeed be the case that individuals could be penalized if they had an eating pattern that included the recommended amount of fruit at the morning meal. It would be interesting to see how often this occurs. Given that approximately 80% of Americans are not meeting the dietary guidelines for fruit,8
it may be unlikely that many study participants were actually eating the recommended amount for the day during the morning meal and being penalized by their lunch choices. Nevertheless, whether or not to adjust the food groups included in an index to measure single meals to avoid penalizing individuals is an important question. Specifically for fruit, the MyPlate icon suggests that fruit should occupy a quarter of an individual’s plate, and the 2020-2025 Dietary Guidelines suggest that focusing on adding fruit to meals may be a good way to achieve the recommended amount.US Depts of Agriculture and Health and Human Services
Dietary Guidelines for Americans, 2020-2025.
Dietary Guidelines for Americans, 2020-2025.
2020
https://www.dietaryguidelines.gov/sites/default/files/2020-12/Dietary_Guidelines_for_Americans_2020-2025.pdf
Date accessed: February 6, 2021
8
, Thus, measuring the extent to which individuals are including fruit in their individual meal choices may be helpful.US Depts of Agriculture and Health and Human Services
Dietary Guidelines for Americans, 2020-2025.
Dietary Guidelines for Americans, 2020-2025.
2020
https://www.dietaryguidelines.gov/sites/default/files/2020-12/Dietary_Guidelines_for_Americans_2020-2025.pdf
Date accessed: February 6, 2021
Another issue raised by the authors of the letter is that “the dietary patterns that were selected were anchored by different components: food groups and/or nutrients” and that we “did not sufficiently emphasize the four patterns selected were anchored by different components.” Our article contained detailed descriptions of each of the indexes and the various components of the indexes in both the Methods and Discussion sections.
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For example, in the Discussion, we state, “each index includes multiple components, some of which overlap and some that differ. The Dietary Approaches to Stop Hypertension Accordance Score and the Nutrient Rich Foods index scores are calculated based on a small number of nutrients to either limit or encourage, whereas HEI-2015 and MMQI scores take into account both nutrients and food groups to limit or encourage.”1
Previous studies have compared indexes “anchored by different components,”10
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and it may not be correct to assume that comparisons of indexes based on different components “would be cumbersome and unwieldy to compare.”We appreciate the suggestion to “harmonize across diet quality indexes” and, as suggested, have conducted new analyses similar to those described in an article about the Dietary Patterns Methods Project
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to compare our four indexes. Similar to the Dietary Patterns Methods Project, we had already calculated the Spearman rank correlation coefficients between the four indexes we selected for our study (Table 1). We have now created quintiles for the scores from each of the indexes and assigned a rank of one to five for each of the observations or “meals” depending on which quintile the score fell into for each index. Similar to the Dietary Patterns Methods Project, we compared score ranks for pairs of indexes by calculating the proportion of observations that were ranked identically and identically/adjacent. For example, a rank of four on HEI-2015 and four on MMQI would be identical ranks, whereas a rank of three or five on HEI-2015 would be an adjacent rank to a four on MMQI. Results of the comparisons of identical and identical/adjacent ranks for each of the pairs of indexes are reported in Table 2.Table 1Spearman correlation coefficients between Healthy Eating Index (HEI-2015) score, the Dietary Approaches to Stop Hypertension (DASH) Accordance Score, the Main Meal Quality Index (MMQI) score, and the Nutrient Rich Foods (NRF) Index score for all meal (lunch) observations (n = 8,070) from business cafeterias in North Carolina that participated in the Effects of Physical Activity Calorie Expenditure Food Labeling research study (2015-2017)
| All meals (N = 8,070) | ||||
|---|---|---|---|---|
| HEI-2015 | DASH | MMQI | NRF | |
| HEI-2015 | 1.00 | 0.26 | 0.40 | 0.29 |
| DASH | 1.00 | 0.68 | 0.63 | |
| MMQI | 1.00 | 0.39 | ||
| NRF | 1.00 | |||
a All correlations significant at P < 0.0001.
Table 2Percent of identical and identical or adjacent quintile rankings between Healthy Eating Index (HEI-2015) scores, the Dietary Approaches to Stop Hypertension (DASH) Accordance Scores, the Main Meal Quality Index (MMQI) scores, and the Nutrient Rich Foods (NRF) Index scores for all meal (lunch) observations (n = 8,070) from business cafeterias in North Carolina that participated in the Effects of Physical Activity Calorie Expenditure Food Labeling research study (2015-2017)
| HEI-2015 (%) | DASH | MMQI | NRF |
|---|---|---|---|
| Identical rank | 25.1 | 28.5 | 25.9 |
| Identical or adjacent rank | 60.3 | 65.8 | 62.7 |
| DASH (%) | |||
| Identical rank | 39.6 | 41.3 | |
| Identical or adjacent rank | 81.6 | 81.0 | |
| MMQI (%) | |||
| Identical rank | 29.5 | ||
| Identical or adjacent rank | 66.9 | ||
Although it is interesting to see the extent to which observations received identical or adjacent ranks by the indexes, we are not sure that harmonizing the indexes provides much more information or changes the conclusions we included in our original article. There is perhaps more agreement or concordance between indexes when considering adjacent ranks, but the same underlying relationships exists between the indexes when using just Spearman correlation coefficients.
Finally, the letter authors mention that we did not adequately address the issue that meals are difficult to define. In our article, in an effort to address this issue, we examined the Spearman correlation coefficients of the four indexes using three different definitions of what could constitute a meal.
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In our case, we did not find that the relationships between indexes changed much using these definitions. One of the definitions we included was based on the “guidelines used to define meals for The Child and Adult Care Food Program and for US Department of Agriculture’s MyPlate.”1
This definition may be useful for future studies focused on assessing the healthfulness of meals or for creating an index specific to meals.We appreciate the interest in our study and hope it can inform future studies and the development or adaptation of meal specific indexes.
References
- Comparisons of four diet quality indexes to define single meal healthfulness.J Acad Nutr Diet. 2022; 122: 149-158
- Evaluation of the psychometric properties of the main meal quality index when applied in the UK population.Eur J Clin Nutr. 2017; 71: 674-676
- Defining nutrient density: development and validation of the nutrient rich foods index.J Am Coll Nutr. 2009; 28: 421S-426S
- Beneficial effect of high energy intake at lunch rather than dinner on weight loss in healthy obese women in a weight-loss program: a randomized clinical trial.Am J Clinical Nutr. 2016; 104: 982-989
- What should be your biggest meal?.2019https://www.livestrong.com/article/469196-what-should-be-your-biggest-meal/Date accessed: July 25, 2022
- This is when you should eat your lightest and heaviest meals of the Day.https://www.womenshealthmag.com/weight-loss/a19967168/lightest-meal-of-the-day/Date: 2017Date accessed: July 25, 2022
- Timing of food intake predicts weight loss effectiveness.Int J Obes (Lond). 2013; 37: 604-611
- Dietary Guidelines for Americans, 2020-2025.2020https://www.dietaryguidelines.gov/sites/default/files/2020-12/Dietary_Guidelines_for_Americans_2020-2025.pdfDate accessed: February 6, 2021
- ChooseMyPlate.2020https://www.choosemyplate.gov/Date accessed: June 12, 2020
- Comparison of 4 established DASH diet indexes: examining associations of index scores and colorectal cancer.American Journal of Clinical Nutrition. 2013; 98: 794-803
- Cross-comparison of diet quality indices for predicting chronic disease risk: findings from the Observation of Cardiovascular Risk Factors in Luxembourg (ORISCAV-LUX) study.Br J Nutr. 2015; 113: 259-269
- Association between diet-quality scores, adiposity, total cholesterol and markers of nutritional status in European adults: findings from the Food4Me study.Nutrients. 2018; 10: 49
- The Dietary Patterns Methods Project: synthesis of findings across cohorts and relevance to dietary guidance.J Nutr. 2015; 145: 393-402
Article info
Publication history
Published online: August 17, 2022
Accepted:
August 16,
2022
Received:
August 8,
2022
Footnotes
STATEMENT OF POTENTIAL CONFLICT OF INTEREST No potential conflict of interest was reported by the author.
FUNDING/SUPPORT The Effects of Physical Activity Calorie Expenditure Food Labeling study was funded by R01 CA184473-01A1 from the National Cancer Institute, National Institutes of Health. The funding body played no role in study design, data collection, analysis, interpretation of data, or writing the manuscript.
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© 2022 by the Academy of Nutrition and Dietetics.
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- Comparisons of Four Diet Quality Indexes to Define Single Meal HealthfulnessJournal of the Academy of Nutrition and DieteticsVol. 122Issue 11
- PreviewThe authors of “Comparisons of Four Diet Quality Indexes to Define Single Meal Healthfulness” published in the January 2022 issue of the Journal of the Academy of Nutrition and Dietetics compared four different diet quality indexes to identify if these indexes could assess “nutrition quality” of single meals.1 The article is problematic in two fundamental areas: dietary patterns address total diet whereas the authors used a single meal/eating occasion, and the dietary patterns that were selected were anchored by different components: food groups and/or nutrients.
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