An 18-year study looking at the diets of 43,996 Americans has resulted in a “report card” with some disappointing results: Americans eat way too many garbage carbohydrates and are still plowing in the saturated fat.
For more years than I’d care to count, America has been getting a steady “diet” of nutritional advice and guidance on healthy eating. Apparently, either they are ignoring the advice or those providing it have lectured us into a state of oppositional and resistant boredom. Maybe they just droned on with the same boring message for so long that Americans said “screw it” and kept eating the processed pseudo-foods we’ve always eaten.
For generations, we’ve been hearing the message about eating healthy, whole foods and avoiding low-quality carbs and saturated fat. Yet this study from the Friedman School of Nutrition Science and Policy at Tufts University and the Harvard T.H. Chan School of Public Health says we fail to measure up. Considering that the study, published in JAMA, looked at diet trends over an 18-year period, they may have a point.
While there were a few bright spots, the study found that low-quality carbs from sources like starchy vegetables, processed foods with added sugars and refined grains still make up about 42% of the typical American diet. High-quality carbs (cruciferous vegetables, whole grains and whole fruits) only account for 9%.
Total carbohydrate consumption did fall by 2% and consumption of low-quality carbs dropped by 3%. But consumption of the healthier carbs only bumped up by 1%.
Fat intake showed no improvement overall. Total intake went up by 1%, of which half was saturated fat. While the recommended daily amount of saturated fat intake is 10% of total calories, Americans ate about 12% of their calories as saturated fat.
Results for older folks and those with lower incomes or educational levels were even worse.
People living below the poverty line saw their low-quality carb intake reduced by 2%, versus 4% for higher income adults during the study period.
While researchers report that most Americans improved their adherence to dietary guidelines during the 18-year period, those with less than a high school education, living below the poverty line or over 50 years of age saw no improvement at all.
“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. Our study tells us where we need to improve for the future,” said co-senior author Fang Fang Zhang, nutrition epidemiologist at the Friedman School of Nutrition Science and Policy at Tufts University. “These findings also 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.”
Researchers dug in on the trends around consumption of specific nutrients. They looked at consumption of plant-based protein and saturated fatty acids. They believe such observations offer insights on how changes in the sourcing of food might offer health benefits.
“For example, most of the proteins that Americans consumed were from meats — including red and processed meat. Proteins consumed from seafood and healthy plant sources, such as whole grains, nuts, and legumes, remained a much smaller proportion,” said co-senior author Shilpa Bhupathiraju, research scientist at the Harvard T.H. Chan School of Public Health, also with Harvard Medical School and Brigham and Women’s Hospital. “Our research suggests that Americans have an opportunity to diversify their sources of protein to include more seafood, beans, soy products, nuts and seeds.”
“Because low-quality carbs are associated with disease risk, taking in higher-quality carbs could mean better health for Americans in the future,” said first author on the study, Zhilei Shan, nutritional epidemiology fellow at the Harvard T.H. Chan School of Public Health. At the time of this study, he was also working under the auspices of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
The study used a large pool of data from the National Health and Nutrition Examination Study (NHANES.) The participant pool was representative of the adult population across America, with each completing at least one valid 24-hour dietary recall report from 9 consecutive cycles of the NHANES, between 1999 and 2016.
Researchers estimated nutrient intake using the USDA’s Food and Nutrition Database for Dietary Studies (FNDDS.) The Healthy Eating Index (HEI) – 2015 was used to assess overall quality of diet. The HEI – 2015 measures adherence to the 2015-2020 Dietary Guidelines for Americans.
The principle limitations of the study include the reality that self-reported food recall data is subject to measurement error to daily variations in food consumption. However, steps were taken, wherever possible and appropriate, by researchers to improve estimates.
Even with the limitations of the study considered, we can assume that either Americans aren’t hearing the message about diet from authorities, it isn’t being delivered effectively or the folks who should be hearing it and making changes just don’t care.
Check your diet. Eat more whole foods. Lay off the processed foods, added sugars and excessive saturated fats.
I mean it. Don’t make me come over there…
Keep the faith and keep after it!
Journal Reference – Zhilei Shan, Colin D. Rehm, Gail Rogers, Mengyuan Ruan, Dong D. Wang, Frank B. Hu, Dariush Mozaffarian, Fang Fang Zhang, Shilpa N. Bhupathiraju. Trends in Dietary Carbohydrate, Protein, and Fat Intake and Diet Quality Among US Adults, 1999-2016. JAMA, 2019