The study,published in JAMA,looked at dietary trends over an 18 year period, according to a press release from Tufts. Researchers examined the diets of 43,996 adults who participated in the National Health and Nutrition Examination Survey. Total carb intake went down 2%, and Americans cut back on low-quality carbs by 3%, but only increased consumption of high-quality carbs by 1%. Low-quality carbs from refined grains, starchy vegetables, and added sugars accounted for 42% of a typical American’s daily calories. High-quality carbs from whole grains and whole fruits only accounted for 9%. Total fat intake increased by 1%, half of which was saturated fat. Saturated fat represented 12% of daily calories—the recommended daily amount is 10%.
There were some dietary improvements—but they were limited. Higher income adults reduced their intake of low-quality carbs by 4%, but those living below the poverty line cut their intake by only 2%; there was no dietary improvement at all in adults over 50 years old, people with less than a high school education, and those living below the poverty line.
Related: Med Students Insufficiently Trained in Nutrition As the Amazon Burns, Experts Urge Plant-Based Diets Study: Unhealthy Diets Account for 11M Deaths AnnuallyAnd while plant-based feels like it’s everywhere, it’s really not. “Most of the proteins that Americans consumed were from meats—including red and processed meat. Proteins consumed from seafood and healthy plant sources remained a much smaller proportion,” according to co-senior author Shilpa Bhupathiraju, Research Scientist at the Harvard T.H. Chan School of Public Health. "Our research suggests that Americans have an opportunity to diversify their sources of protein to include more seafood, beans, soy products, nuts and seeds."
Co-senior author Fang Fang Zhang, Nutrition Epidemiologist at the Friedman School of Nutrition Science and Policy at Tufts University, said: “Although there are some encouraging signs that the American diet improved slightly over time, we are still a long way from getting an 'A' on this report card. These findings highlight the need for interventions to reduce socioeconomic differences in diet quality, so that all Americans can experience the health benefits of an improved diet."