Proportion of US Adults Eating "Ideal Diet" More Than Doubles, But Remains Under 2%
American diets still have a long way to go, say researchers.

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American eating habits are going in the right direction, say researchers, but at a slow pace.
After analysing the records of 51,703 adults who filled in dietary surveys between 1999 and 2020, the researchers from Mount Sinai and Tufts University found that a significantly higher proportion of US adults were now eating a healthier diet.
In this 21-year period, the proportion of adults eating a “poor” diet decreased from 48.8% to 37.4%, the proportion eating an “intermediate quality” diet rose from 50.6% to 61.1% and the percentage eating an “ideal” diet increased from 0.66% to 1.58%.
While all these figures moved in the right direction, the researchers say the American public still has a long way to go to rid itself of the detriments of poor nutrition.
The results were published in the Annals of Internal Medicine.
American pies
Unhealthy diets have underpinned much of the USA’s healthcare issues for several decades. Each year, more than one million Americans die from diet-related diseases, according to the US Food and Drug Administration.
To check if there had been any small improvements in the nation’s eating habits in recent years, the Mount Sinai and Tufts University researchers accessed 10 cycles of the National Health and Nutrition Examination Survey, a nationally representative survey that asks participants to recall everything they ate over the latest 24 hours.
The researchers looked at data from 51,703 adults who had completed at least one valid 24-hour recall; 72.6% of these had given two recalls.
Diet quality was measured using the American Heart Association diet score, which values components like fruits, vegetables, beans, nuts and whole grains and devalues items like sugary beverages and processed meat.
The researchers found that the proportion of adults with poor dietary 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 proportion of adults with an “ideal diet” more than doubled – from 0.66% to 1.58% – but still remained starkly low.
These improvements appeared to be driven by higher intakes of nuts and seeds, whole grains, poultry, cheese and eggs, as well as lower intakes of refined grains, drinks with added sugar, fruit juice and milk. Total intake of fruits and vegetables, fish/shellfish, processed meat, potassium and sodium remained relatively stable.
Not everyone was making improvements to their diets, though; most of this new nutrition was being eaten by younger adults, women, Hispanic adults and people with higher levels of education and income. Older adults, men, Black adults and people with lower levels of education and less income had less dietary change, although nutritional gains were still observed.
The researchers say these data highlight how people from certain, often marginalized demographics are still at risk from type 2 diabetes, cardiovascular disease and other consequences of poor diets.
“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,” said first author Junxiu Liu, a postdoctoral scholar at Tufts’ Friedman School at the time of the study, now assistant professor at the Icahn School of Medicine at Mount Sinai.
Moreover, the proportion of adults with poor diet quality decreased across income thresholds: from 51.8% to 47.3% among individuals with lower income, from 50.0% to 43.0% among individuals with middle income and from 45.7% to 29.9% among individuals with higher income.
“We face a national nutrition crisis, with continuing climbing rates of obesity and type 2 diabetes,” said Dariush Mozaffarian, cardiologist and director of the Food is Medicine Institute and senior author of the study. “These diseases afflict 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 to address the human and economic costs of poor diets.”
Reference: Liu J, Mozaffarian D. Trends in diet quality among U.S. adults from 1999 to 2020 by race, ethnicity, and socioeconomic disadvantage. Ann. Of Intern. Med. 2024. doi: 10.7326/M24-0190
This article is a rework of a press release issued by Tufts University. Material has been edited for length and content.