Poor American diets remain a significant issue in the United States, contributing to obesity, type 2 diabetes, cardiovascular disease, and certain cancers. According to the Food and Drug Administration, more than one million Americans die each year from diet-related diseases. The financial impact is also substantial, with an estimated $1.1 trillion spent on healthcare and lost productivity due to poor diet and food insecurity. These issues disproportionately affect individuals based on income, education, zip code, race, and ethnicity, highlighting significant health disparities.
Modest Progress in American Diets
A recent study from the Food is Medicine Institute at the Friedman School of Nutrition Science and Policy reveals some progress. The research shows that diet quality among U.S. adults improved modestly between 1999 and 2020. However, the number of Americans with poor diet quality remains high, and disparities in diet quality persist.
“While we’ve seen some modest improvement in American diets in the last two decades, those improvements are not reaching everyone, and many Americans are eating worse,” said study senior author Dariush Mozaffarian, cardiologist and director of the Food is Medicine Institute. “Our new research shows 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.”
Analysis of American Diets
The study analyzed data from 10 cycles of the National Health and Nutrition Examination Survey (NHANES) conducted between 1999 and 2020. This includes repeated 24-hour dietary recalls from 51,703 adults, with 72.6% completing two recalls. Diet quality was measured using the American Heart Association diet score, which evaluates the consumption of fruits, vegetables, beans, nuts, whole grains, sugary beverages, and processed meat.
The results showed that the proportion of adults with poor diet quality decreased from 48.8% to 36.7% over the two decades, while those with intermediate diet quality increased from 50.6% to 61.1%. The percentage of adults with an ideal diet remained very low but still improved, increasing from 0.66% to 1.58%.
The study noted specific changes contributing to these trends, such as increased consumption of nuts, seeds, whole grains, poultry, cheese, and eggs. Conversely, there was a decrease in the intake of refined grains, sugary drinks, fruit juice, and milk. However, the overall consumption of fruits and vegetables, fish, processed meat, potassium, and sodium remained stable.
Disparities in Dietary Improvements
The improvements in diet quality were not evenly distributed across the population. The greatest gains were seen among younger adults, women, Hispanic adults, and those with higher education, income, food security, and private health insurance. Conversely, older adults, men, Black adults, and individuals with lower education, income, food insecurity, or non-private health insurance saw smaller improvements.
For instance, the proportion of adults with poor diet quality decreased from 51.8% to 47.3% among those with lower income, from 50.0% to 43.0% among those with middle income, and from 45.7% to 29.9% among those with higher income.
“While some improvement, especially lower consumption of added sugar and fruit drinks, is encouraging to see, we still have a long way to go, especially for people from marginalized communities and backgrounds,” noted Junxiu Liu, the study’s first author and former postdoctoral scholar at the Friedman School, now assistant professor at the Icahn School of Medicine at Mount Sinai.
Addressing the Nutrition Crisis
The research underscores the ongoing national nutrition crisis related to American diets, with rising rates of obesity and type 2 diabetes. These conditions affect all Americans but are particularly prevalent among socioeconomically and geographically vulnerable populations.
Mozaffarian emphasizes the need to address nutrition security and other social determinants of health – including housing, transportation, fair wages, and structural racism – to mitigate the human and economic costs of poor diets. The journey toward achieving health equity through improved diets is ongoing. While there are signs of progress, much work remains to ensure that all Americans have access to nutritious food and the opportunity to lead healthy lives.