Dietary quality and dietary greenhouse gas emissions in the USA: a comparison of the planetary health diet index, healthy eating index-2015, and dietary approaches to stop hypertension

BACKGROUND

The Planetary Health Diet Index (PHDI) measures adherence to the dietary pattern presented by the EAT-Lancet Commission, which aligns health and sustainability targets. There is a need to understand how PHDI scores correlate with dietary greenhouse gas emissions (GHGE) and how this differs from the carbon footprints of scores on established dietary recommendations. The objectives of this study were to compare how the PHDI, Healthy Eating Index-2015 (HEI-2015) and Dietary Approaches to Stop Hypertension (DASH) relate to (a) dietary GHGE and (b) to examine the influence of PHDI food components on dietary GHGE.

METHODS

We used life cycle assessment data from the Database of Food Recall Impacts on the Environment for Nutrition and Dietary Studies to calculate the mean dietary GHGE of 8,128 adult participants in the 2015-2016 and 2017-2018 cycles of the National Health and Nutrition Examination Survey (NHANES). Poisson regression was used to estimate the association of (a) quintiles of diet score and (b) standardized dietary index Z-scores with dietary GHGE for PHDI, HEI-2015, and DASH scores. In secondary analyses, we used Poisson regression to assess the influence of individual PHDI component scores on dietary GHGE.

RESULTS

We found that higher dietary quality on all three indices was correlated with lower dietary GHGE. The magnitude of the dietary quality-dietary GHGE relationship was larger for PHDI [-0.4, 95% CI (-0.5, -0.3) kg CO2 equivalents per one standard deviation change] and for DASH [-0.5, (-0.4, -0.6) kg CO2-equivalents] than for HEI-2015 [-0.2, (-0.2, -0.3) kg CO2-equivalents]. When examining PHDI component scores, we found that diet-related GHGE were driven largely by red and processed meat intake.

CONCLUSIONS

Improved dietary quality has the potential to lower the emissions impacts of US diets. Future efforts to promote healthy, sustainable diets could apply the recommendations of the established DASH guidelines as well as the new guidance provided by the PHDI to increase their environmental benefits.

Identifying and Estimating Ultraprocessed Food Intake in the US NHANES According to the Nova Classification System of Food Processing

BACKGROUND

The degree of food processing may be an important dimension of diet in how it relates to health outcomes. A major challenge is standardizing food processing classification systems for commonly used datasets.

OBJECTIVES

To standardize and increase transparency in its application, we describe the approach used to classify foods and beverages according to the Nova food processing classification in the 24-h dietary recalls from the 2001-2018 cycles of What We Eat in America (WWEIA), NHANES, and investigate variability and potential for Nova misclassification within WWEIA, NHANES 2017-2018 data via various sensitivity analyses.

METHODS

First, we described how the Nova classification system was applied to the 2001-2018 WWEIA, NHANES data using the reference approach. Second, we calculated the percentage energy from Nova groups [1: unprocessed or minimally processed foods, 2: processed culinary ingredients, 3: processed foods, and 4: ultraprocessed foods (UPFs)] for the reference approach using day 1 dietary recall data from non-breastfed participants aged ≥1 y from the 2017-2018 WWEIA, NHANES. We then conducted 4 sensitivity analyses comparing potential alternative approaches (e.g., opting for more vs. less degree of processing for ambiguous items) to the reference approach, to assess how estimates differed.

RESULTS

The energy contribution of UPFs using the reference approach was 58.2% ± 0.9% of the total energy; unprocessed or minimally processed foods contributed 27.6% ± 0.7%, processed culinary ingredients contributed 5.2% ± 0.1%, and processed foods contributed 9.0% ± 0.3%. In sensitivity analyses, the dietary energy contribution of UPFs ranged from 53.4% ± 0.8% to 60.1% ± 0.8% across alternative approaches.

CONCLUSIONS

We present a reference approach for applying the Nova classification system to WWEIA, NHANES 2001-2018 data to promote standardization and comparability of future research. Alternative approaches are also described, with total energy from UPFs differing by ∼6% between approaches for 2017-2018 WWEIA, NHANES.

Changes in diet quality and food security among adults during the COVID-19-related early lockdown: results from NutriQuébec

BACKGROUND

The impact that the coronavirus disease 2019 (COVID-19)-related early lockdown has had on dietary habits of the population and on food insecurity is unknown.

OBJECTIVE

The aim of this study was to document the change in diet quality and in food insecurity observed during the COVID-19-related early lockdown. We hypothesized that the lockdown was associated with a deterioration in overall diet quality and an increase in food insecurity.

METHODS

Data are from a COVID-19 subsample of NutriQuébec, a web-based cohort destined to study temporal changes in dietary habits among adults in Quebec, Canada. Participants completed questionnaires before (between June 2019 and February 2020) and during (April to May 2020) early lockdown, including a validated web-based 24-h recall (n = 853) and a questionnaire on food security (n = 922). Primary study outcomes were temporal changes in diet quality measured by the Healthy Eating Index (HEI)-2015 and in the prevalence of food insecurity.

RESULTS

There was a small increase in the HEI-2015 during the COVID-19 early lockdown compared with baseline (+1.1 points; 95% CI: 0.6, 1.5), mostly due to small improvements in the intakes of whole grains, greens and beans, refined grains, total vegetables, total dairy, seafood and plant proteins, added sugar, and total protein subscores of the HEI-2015. Exploratory analyses suggested that individuals aged 18-29 y (+3.6 points; 95% CI: 2.4, 4.7), participants with lower education (+1.9 points; 95% CI: 1.3, 2.6), or with obesity (+3.8 points; 95% CI: 2.7, 4.8) showed particularly important increases in the HEI-2015. The prevalence of food insecurity was reduced from 3.8% at baseline to 1.0% during the early lockdown (prevalence ratio = 0.27; 95% CI: 0.08, 0.94).

CONCLUSIONS

Contrary to our hypotheses, diet quality has slightly improved and prevalence of food insecurity was reduced in this sample of adults from Quebec during the COVID-19-related early lockdown. These results may be generalizable only to relatively healthy populations.

Self-Report Dietary Assessment Tools Used in Canadian Research: A Scoping Review

Choosing the most appropriate dietary assessment tool for a study can be a challenge. Through a scoping review, we characterized self-report tools used to assess diet in Canada to identify patterns in tool use and to inform strategies to strengthen nutrition research. The research databases Medline, PubMed, PsycINFO, and CINAHL were used to identify Canadian studies published from 2009 to 2014 that included a self-report assessment of dietary intake. The search elicited 2358 records that were screened to identify those that reported on self-report dietary intake among nonclinical, non-Aboriginal adult populations. A pool of 189 articles (reflecting 92 studies) was examined in-depth to assess the dietary assessment tools used. Food-frequency questionnaires (FFQs) and screeners were used in 64% of studies, whereas food records and 24-h recalls were used in 18% and 14% of studies, respectively. Three studies (3%) used a single question to assess diet, and for 3 studies the tool used was not clear. A variety of distinct FFQs and screeners, including those developed and/or adapted for use in Canada and those developed elsewhere, were used. Some tools were reported to have been evaluated previously in terms of validity or reliability, but details of psychometric testing were often lacking. Energy and fat were the most commonly studied, reported by 42% and 39% of studies, respectively. For ∼20% of studies, dietary data were used to assess dietary quality or patterns, whereas close to half assessed ≤5 dietary components. A variety of dietary assessment tools are used in Canadian research. Strategies to improve the application of current evidence on best practices in dietary assessment have the potential to support a stronger and more cohesive literature on diet and health. Such strategies could benefit from national and global collaboration.

Household Food Insecurity Is a Stronger Marker of Adequacy of Nutrient Intakes among Canadian Compared to American Youth and Adults

BACKGROUND

The most recent statistics indicate that the prevalence of food insecurity in the United States is double that in Canada, but the extent to which the nutrition implications of this problem differ between the countries is not known.

OBJECTIVE

This study was undertaken to compare adequacy of nutrient intakes in relation to household food insecurity among youth and adults in Canada and the United States.

METHODS

Data from comparable nationally representative surveys, the 2004 Canadian Community Health Survey and the 2003-2006 NHANES, were used to estimate prevalences of inadequate intakes of vitamins A and C, folate, calcium, magnesium, and zinc among youth and adults in food-secure and food-insecure households. Potential differences in the composition of the populations between the 2 countries were addressed by using standardization, and analyses also accounted for participation in food and nutrition assistance programs in the United States.

RESULTS

Larger gaps in the prevalences of inadequate intakes between those in food-secure and food-insecure households were observed in Canada than in the United States for calcium and magnesium. For calcium, the prevalences of inadequate intakes among those in food-secure and food-insecure households in Canada were 50% and 66%, respectively, compared with 50% and 51%, respectively, in the United States. For magnesium, the prevalences of inadequate intakes in Canada were 39% and 60% among those in food-secure and food-insecure households, respectively, compared with 60% and 61%, respectively, in the United States. These findings were largely unchanged after we accounted for participation in food and nutrition assistance programs in the United States.

CONCLUSIONS

This study suggests that household food insecurity is a stronger marker of nutritional vulnerability in Canada than in the United States. The results highlight the need for research to elucidate the effects of domestic policies affecting factors such as food prices and fortification on the nutritional manifestations of food insecurity.

Which dietary diversity indicator is best to assess micronutrient adequacy in children 1 to 9 y?

OBJECTIVES

The aim of this study was to determine the best dietary diversity indicator to measure dietary diversity and micronutrient adequacy in children.

METHODS

A national representative cross-sectional survey of children ages 1 to 9 y (N = 2,200) was undertaken in all ethnic groups in South Africa. A 24-h recall was done with the mother or caregiver of each child. A dietary diversity score (DDS), the number of food groups consumed at least once in a period of 24 h, was calculated for each child in accordance with 6-, 9-, 13-, and 21-food group (G) indicators and compared with a mean adequacy ratio (MAR). The nutrient adequacy ratio (NAR) was calculated for 11 micronutrients by comparing the distributions of estimated intakes with the Estimated Average Requirements for that micronutrient. The MAR was the average of all NARs. Correlations were done between MAR and DDS and sensitivity and specificity calculated for each group indicator.

RESULTS

Pearson's correlations between food group indicators and MAR indicate that r values were all highly significant (P < 0.0001). There were no consistent or large differences found between the different group indicators although G13 and G21 appeared to be marginally better. Sensitivity and specificity values in the current study lay between DDS of 3 and 5, suggesting one of these as the best indication of (low) micronutrient adequacy.

CONCLUSIONS

Overall results seem to indicate that any of the four G indicators can be used in dietary assessment studies on children, with G13 and G21 being marginally better. A cut-off DDS of 4 and 5, respectively, appear best.

Eight self-administered 24-hour dietary recalls using the Internet are feasible in African Americans and Whites: the energetics study

OBJECTIVE

To support research and to provide food and nutrition practitioners with a strong foundation for nutrient-based counseling, there is a need for affordable automated 24-hour dietary recalls. Multiple days of intake, along with repeated reports over time, are needed to achieve stable indicators of individual intakes and to support evaluation of success in meeting dietary goals because of intraindividual intake variability. Little information has been published on subject responses, participation rates, and the perceived subject burden of repeated 24-hour recalls. Our aim was to determine the willingness of subjects to conduct eight 24-hour recalls via the Internet.

DESIGN

A study to validate a Web-based, automated, self-administered 24-hour recall (DietDay, Centrax Corporation, Chicago, IL).

SUBJECTS/SETTING

Two-hundred and sixty-one white and African-American subjects within 50 miles of the University of California-Los Angeles participated in the study. Subjects completed 3 DietDays at the study visits and another 5 days on their own. The last 2 DietDays were completed 1 and 2 months after the final clinic visit. Subjects were notified by automatic e-mail of the need for DietDay completion, and nonresponders were followed up with personalized e-mails and phone calls.

RESULTS

The perceived subject burden was minimal and, even after completing six recalls, 92% were willing to continue reporting their daily diets 1 and 2 months later. White subjects had a slightly higher rate of return, with 94% completing all eight recalls, compared to 91% of African-American subjects. Participants were able to access the Internet in their homes, offices, library, or homes of friends or family. It is also of interest that 82% of subjects believed the 24-hour recall was superior to a diet history in reflecting their normal diet.

CONCLUSION

These results open up new opportunities for food and nutrition practitioners to strengthen their nutritional counseling in an efficient and affordable manner without additional time investment.