Dietary Assessment and Surveys

There is limited data on trends in diet quality among U.S. adults. To assess changes in diet quality across different racial, ethnic, and socioeconomic groups, this study by Liu & Mozaffarian (2024) used repeated cross-sectional data, evaluating the American Heart Association's (AHA) 2020 continuous diet score which focuses on increased consumption of vegetables, fruits, fish, whole grains, shellfish, seeds, nuts, and legumes, and reduced intake of processed meat, sugar-saturated fat, sweetened beverages, and sodium, in addition to the adjusted consumption of these and other food categories and nutrients, as well as compliance with the Healthy Eating Index (HEI)-2015. Less than 40% adherence to the AHA score was considered a poor diet, 40% to 79.9% was considered moderate, and at least 80% was considered good. The analysis comprised 51703 adults aged 20 and above who participated in the 1999-2020 National Health and Nutrition Examination Survey (NHANES). The proportion of adult Americans with poor diet quality fell from 48.8% to 37.4% between 1999 and 2020. In contrast, the proportion of adults with intermediate diet quality climbed from 50.6% to 61.1%, and the proportion of adults with perfect diet quality increased from 0.66% to 1.58%. Across a range of factors, including age, sex, color, ethnicity, education, income, food security, membership in the Supplemental Nutrition Assistance Program, and health insurance coverage, persistent or growing differences in diet quality were seen. For instance, among those with food security, the percentage of people with poor diet quality fell from 47.9% to 33.0%, whereas among those without, it stayed mostly stable from 51.3% to 48.2%. Similar trends were observed for HEI-2015. Although there was a little increase in the quality of the diet among adults in the United States between 1999 and 2020, a sizable fraction of adults still had a poor diet, and dietary inequities continue to exist or worsen.