Poor diet remains a significant burden on American adults, posing major risks such as obesity, type 2 diabetes, cardiovascular disease, and certain cancers. According to the Food and Drug Administration, more than one million Americans die annually from diet-related diseases. The economic toll is staggering, too, with poor diet and food insecurity contributing an estimated $1.1 trillion to healthcare costs and lost productivity. These issues exacerbate health disparities across income levels, education, geographical locations, and racial and ethnic backgrounds.
Recent research from the Food is Medicine Institute at Tufts University’s Friedman School of Nutrition Science and Policy, published in the Annals of Internal Medicine, highlights some improvements in diet quality among U.S. adults from 1999 to 2020. Despite these gains, many Americans still have poor diet quality, and disparities persist or worsen over time.
Lead researcher Dariush Mozaffarian, director of the Food is Medicine Institute, notes that modest improvements in American diets have yet to be equitable across the population. Many Americans continue to experience barriers in accessing and consuming nourishing foods, hindering progress towards nutritional and health equity.
The study analysed data from 51,703 adults over ten National Health and Nutrition Examination Survey cycles, using the American Heart Association diet score to measure diet quality. It found a decrease in the proportion of adults with poor diet quality from 48.8% to 36.7% over the two decades studied, with a corresponding increase in those with intermediate diet quality. However, the percentage of adults with an ideal diet remained strikingly low, showing minimal improvement.
Fundamental dietary changes contributing to these trends included increased consumption of nuts, seeds, whole grains, poultry, cheese, and eggs, alongside decreased intake of refined grains, sugary beverages, and fruit juice. Consumption of fruits, vegetables, fish, shellfish, processed meats, potassium, and sodium remained relatively stable.
Despite these overall trends, disparities in diet quality improvement were evident across different demographic groups. Younger adults, women, Hispanic adults, and those with higher education, income levels, food security, and private health insurance showed more significant gains in dietary quality. Conversely, older adults, men, Black adults, and individuals with lower socioeconomic status or non-private health insurance saw less improvement or even worsening diet quality.
Junxiu Liu, the study’s first author, emphasised that while some progress is visible, particularly in reducing consumption of added sugars and fruit drinks, significant challenges remain, especially for marginalised communities. These groups continue to face higher rates of obesity and type 2 diabetes, underscoring the urgent need to address nutrition security and broader social determinants of health such as housing, transportation, fair wages, and structural racism.
Mozaffarian reiterated the urgency of addressing these issues comprehensively, advocating for policies and interventions that tackle not only dietary habits but also the underlying social and economic factors perpetuating poor health outcomes. He highlighted the importance of addressing nutrition security alongside other social determinants of health to mitigate the human and financial costs associated with inadequate diets.
While there have been some improvements in diet quality among Americans over the past two decades, these gains have been unevenly distributed across different demographic groups. Achieving nutritional and health equity requires concerted efforts to remove barriers to accessing nutritious foods and address the broader social determinants contributing to disparities in diet quality and related health outcomes.
More information: Junxiu Liu et al, Trends in Diet Quality Among U.S. Adults From 1999 to 2020 by Race, Ethnicity, and Socioeconomic Disadvantage, Annals of Internal Medicine. DOI: 10.7326/M24-0190
Journal information: Annals of Internal Medicine Provided by Tufts University
