The good news? American diets have progressed in a healthier direction over the past 20 years. The bad news? Food insecurity appears to have remained the same over that same time period.
That’s according to a study published Monday in the Annals of Internal Medicine by researchers at Tufts University who analyzed Americans’ diet quality from 1999 to 2020. The researchers found that the percentage of adults with poor diet quality decreased from 48.8% to 37.4% during that period, but persistent or worsening disparities in diet quality continue to impact the chances of achieving health equity.
“While Americans’ diets have improved slightly over the past two decades, those improvements have not reached everyone, and many Americans’ diets are worsening,” said Dariush Mozaffarian, a cardiologist and lead author of the study. “Our new research shows that the nation will not achieve nutrition and health equity unless we address the barriers many Americans face to accessing and eating nutritious foods.”
The study data included information on 51,703 subjects who took part in the National Health and Nutrition Examination Survey over the past 20 years, in which respondents were asked to report all foods and beverages they had consumed on the previous day.
Their intake was then compared to the American Heart Association Diet Score, which the researchers say is a “valid measure of a healthy diet” that is based on high intakes of fruits, vegetables, whole grains, beans, nuts, and seeds (considered an “ideal” diet) while low in sugary drinks, processed meat, saturated fat, and sodium (considered a “bad” diet).
The researchers found that the proportion of adults with poor-quality diets had decreased, and the proportion with fair-quality and excellent diets had increased, although the proportion with excellent diets “remained extremely low,” increasing only from 0.66% to 1.58% over the 20-year period.
Specific trends noted in the study included increases in intake of “ideal” dietary foods such as nuts, seeds, whole grains, poultry, cheese and eggs, and decreases in intake of poorer quality foods such as fruit juice, milk, sugar-sweetened beverages and refined grains, while total intakes of fruits, vegetables, processed meats, seafood, potassium and sodium remained relatively stable.
But the study found that these improvements were not universal. Improvements were strongest among younger adults, women, Hispanic adults, those with higher education, higher income, greater food security, and those with private health insurance. Improvements were smaller among older adults, men, black adults, those with lower education, lower income, lack of food security, and those without private health insurance.
“We face a national nutrition crisis as rates of obesity and type 2 diabetes continue to rise,” Mozaffarian said. “These diseases affect all Americans, but especially those who are socioeconomically and geographically vulnerable. We must address nutrition security and other social determinants of health, including housing, transportation, fair wages and structural racism, and tackle the human and economic costs of unhealthy diets.”
According to the U.S. Food and Drug Administration, more than one million Americans die each year from diet-related illnesses, including cardiovascular disease, diabetes, certain types of cancer and diseases that result from obesity.
But the statistics disproportionately affect minority groups: According to the FDA, four in 10 American adults have high blood pressure, compared with an average of six in 10 non-Hispanic black adults.
Another study from Tufts University found that unhealthy diets and food insecurity contribute an estimated $1.1 trillion in annual health care spending and lost productivity.
