Diet quality plays a crucial role in public health, influencing the risk of chronic diseases and overall well-being. A recent study published in the Annals of Internal Medicine sheds light on the trends in diet quality among U.S. adults from 1999 to 2020, revealing both improvements and persistent challenges.
Overview of the Study
The study, conducted by the Food is Medicine Institute at the Friedman School of Nutrition Science and Policy at Tufts University, analyzed data from 10 cycles of the National Health and Nutrition Examination Survey (NHANES), involving 51,703 adults. Researchers used the American Heart Association (AHA) diet score to assess trends in diet quality over two decades.
Improvements in Diet Quality
From 1999 to 2020, the proportion of adults with poor diet quality decreased from 48.8% to 36.7%, while those with intermediate diet quality increased from 50.6% to 61.1%. The proportion of adults with an ideal diet, although still low, improved from 0.66% to 1.58%. Key dietary changes included higher intakes of nuts/seeds, whole grains, poultry, and lower consumption of refined grains and sugary beverages.
Dr. Dariush Mozaffarian, the senior author of the study, was quoted by CNN as saying, “Americans are starting to hear the message about nutrition, and some companies and restaurants are starting to make healthier products. It’s a little bit of an improvement.”
Persistent Disparities
The improvements were not universal though. Gains in dietary quality were most significant among younger adults, women, Hispanic adults, and individuals with higher levels of education, income, food security, and access to private health insurance.
Progress was less pronounced among older adults, men, Black adults, and individuals with lower education, less income, food insecurity, or non-private health insurance.
For example, the proportion of adults with poor diet quality decreased from 51.8% to 47.3% among those with lower income, from 50% to 43.0% among those with middle income, and from 45.7% to 29.9% among those with higher income.
“We believe it is imperative to understand the trends and disparities in diet quality in the United States and address the potential disparities by population subgroups to promote health equity and human well-being,” said the study’s first author, Junxiu Liu.
Dr. Mozaffarian emphasized that the nation “can’t achieve nutritional and health equity until we address the barriers many Americans face when it comes to accessing and eating nourishing food.”
Health and Economic Impact
According to The Center for Science in the Public Interest, poor diet is a major cause of mortality in the United States, contributing to more than 500,000 deaths each year. The prevalence of diet-related health issues among U.S. adults is alarming: over 70% are overweight or obese; approximately 50% have diabetes or prediabetes; and more than 90% exhibit poor cardiometabolic health. This poor health is characterized by excessive weight, elevated blood sugar levels, high blood pressure, abnormal lipid levels (or the use of medications to manage these conditions), or a history of cardiovascular disease.
The financial burden of medical expenses and lost productivity due to overweight and diet-related illnesses is estimated to be nearly $1 trillion annually, even before considering the costs of new, expensive diet medications.
Challenges and Barriers
Barriers to improving diet quality include food insecurity, lack of nutrition education, and the pervasive influence of advertising on dietary choices. These challenges disproportionately affect marginalized communities, exacerbating health disparities.
Policy and Systemic Solutions
To address these issues, systemic changes are needed. Policy interventions should focus on improving access to affordable, nutritious foods, enhancing nutrition education, and ensuring healthier school meals. Additionally, addressing social determinants of health, such as housing, transportation, fair wages, and structural racism, is essential for improving diet quality and health equity.
Conclusion
While modest improvements in diet quality have been made over the past two decades, significant challenges remain. A comprehensive approach involving policy changes, improved access to healthy foods, education, and healthcare support is necessary to further enhance diet quality and reduce health disparities among U.S. adults.
References
- Junxiu Liu, Dariush Mozaffarian. Trends in Diet Quality Among U.S. Adults From 1999 to 2020 by Race, Ethnicity, and Socioeconomic Disadvantage. Ann Intern Med. [Epub 18 June 2024]. doi:10.7326/M24-0190
- CNN. (2024). America’s diet quality moved from an F to a D. Here’s how to turn yours into an A https://edition.cnn.com/2024/06/17/health/improve-diet-quality-tips-wellness/index.html
- UPI. (2024). American diets improve, but remain poor for many, Tufts study says. https://www.upi.com/Health_News/2024/06/17/American-diet-disparities-study/3571718644236/
- Tufts.edu. (2024). American Diets Have a Long Way to Go to Achieve Health Equity. https://now.tufts.edu/2024/06/17/american-diets-have-long-way-go-achieve-health-equity
- Center for Science in the Public Interest. (2024). Letter to the Appropriations Committee in support of critical funding for NIH Office of Nutrition Research. https://www.cspinet.org/resource/letter-appropriations-committee-support-critical-funding-nih-office-nutrition-research
