NEW YORK (Reuters Health) – A new study of Americans’ eating habits finds that people are choosing more healthy foods and less of the unhealthy ones, overall, and consumption of trans fats has plummeted over a decade.
But scores for diet quality largely improved among more educated and well-off Americans, resulting in a gap between rich and poor that was wider in 2010 than in 1999.
“That increasing gap is a very big concern because it translates directly to suffering from heart disease, diabetes, cancers and also longevity, so it's a pretty serious concern,” Dr. Walter Willett told Reuters Health in an email.
Willett is chair of the nutrition department at the Harvard School of Public Health in Boston and senior author of the new study.
“It's part of a bigger picture of many trends going in the wrong direction with income and also increasing gaps in mortality we see, and the nutrition part is a very important piece of that picture,” he said.
Willett’s team, whose findings are published in JAMA Internal Medicine, used information from almost 30,000 adults in the annual National Health and Nutrition Examination Survey from 1999 through 2010.
They factored in age, race, education and economic status and scored the quality of people’s diets according to an Alternate Healthy Eating Index (AHEI) based on established links between specific foods and disease.
Healthy foods like nuts, vegetables, fruits and fish, which are linked to lower rates of cardiovascular disease, cancer and other illnesses, get high scores on the AHEI. Conversely, junk foods, animal fats and excessive alcohol, which are all linked to higher disease risks, get lower AHEI scores. A perfect AHEI score is 110, and in general, the higher the score, the better a person’s diet.
When the research team looked at the decade-long study period overall, they found the average American AHEI diet quality score increased from 39.9 in the 1999-2000 survey to 46.8 in 2009-2010.
Lower consumption of trans fat accounted for more than half of the score increase. Other sources of improvement over time included less consumption of sugar-sweetened beverages and fruit juice.
But rising sodium consumption dropped the national score by about half a point.
Despite the general improvement, the authors found that scores for vegetable, fruit, whole grains, nuts and legumes, omega-3 fats and moderate alcohol consumption were still too low.
And when they looked at diets by socioeconomic status, the study team found that more affluent Americans and those with college degrees had the highest scores and the largest improvements. As a result, the distance between rich and poor in diet scores almost doubled from 3.9 points to 7.8 points over the length of the study.
Other disparities also emerged, including that women generally had higher AHEI scores than men, and Mexican-Americans had higher scores than non-Hispanic whites and blacks. The researchers suggested that both culture and access to healthy foods likely play a role in the differences among groups.
“Good news is that we could celebrate that diet quality is improving overall. Bad news is that the diet disparity is increasing,” Dr. Takehiro Sugiyama told Reuters Health in an email.
Sugiyama is with the National Center for Global Health and Medicine in Tokyo, Japan, and co-authored a commentary on the study in the same issue of the journal.
“Individual efforts to improve diet quality should be encouraged, but we should not rely solely on individuals’ responsibilities,” he said.
Sugiyama suggests restricting Supplemental Nutrition Assistance Program (SNAP) benefits, formerly known as food stamps, to more healthful foods and providing healthful foods to students and residents in underserved areas.
“I think it's important to look in the critical way at the SNAP, or food stamp, program because we are spending almost $80 billion dollars per year on the program so there's a lot of money being spent, but it's mostly being spent on soda and junk food,” Willett said.
Willett added that SNAP is essential because many low-income families would not get enough to eat without it.
“But we should be making a program that solves other problems like obesity, diabetes, and heart disease at the same time it's giving people enough to eat,” he said.
For individuals interested in their health and well-being, Willett suggests an easy diet review.
“There are a few simple points, basically a little checklist that you can go through to think of areas where you might improve dietary quality,” he said.
Willett said those points include eating more fruits and vegetables, choosing more whole grains and less refined grains, consuming less red meat and fewer sugar-sweetened beverages and using healthy vegetable oils where possible instead of butter or other hard fats. He also suggests consuming less salt and avoiding trans fats.
“I think going through that simple little list can be a reminder to identify possible ways to improve diet quality,” he said. “And this is important because it really can make a big difference in risks of diabetes, heart disease, some cancers and longevity.”