Poor diet among Americans has been a source of worry, particularly raising the risks of chronic health issues such as obesity, type 2 diabetes, cardiovascular disease, and certain cancers. A new study report indicates a modest improvement in diet quality over the past two decades.

However, there is still a long way to go as the number of Americans with poor diet quality remains stubbornly high, and dietary disparities persist or are worsening.

The study featured in the journal Annals of Internal Medicine examined dietary information from 51,703 adults who participated in the National Health and Nutrition Examination Survey from 1999 to 2020. The survey involved multiple 24-hour dietary recalls, where participants reported all foods and drinks consumed the previous day. The diet quality of the participants was assessed using the American Heart Association diet score.

Researchers observed a decrease in poor diet quality from 48.8% to 37.4%, an increase in intermediate quality from 50.6% to 61.1%, and an increase in ideal quality from 0.66% to 1.58%. These positive changes in the trend could be due to higher intake of nuts, seeds, whole grains, poultry, cheese, and eggs, and lower consumption of refined grains, drinks with added sugar, fruit juice, and milk.

However, when the subgroups were analyzed, the researchers found that these improvements were not universal. They observed persistent or worsening disparities in diet quality by various factors such as age, sex, race and ethnicity, education, income, food security, Supplemental Nutrition Assistance Program participation, and health insurance coverage.

Although younger adults, women, Hispanic individuals, and those with higher education, income, food security, and private health insurance exhibited the highest dietary quality, it was lower among older adults, men, Black individuals, and those with lower education, income, food insecurity, or non-private health insurance.

"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. 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," Dariush Mozaffarian, senior author of the latest study, said in a news release.

"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," Junxiu Liu, the first author, added.