When it comes to the American diet, there’s good news and there’s bad news. The good news is that Americans are eating roughly 3% less highly processed foods with added sugar. The bad news? We are still eating large quantities of added sugars, refined grains, and saturated fats. This is according to an analysis of the eating habits of almost 44,000 US adults between 1999 and 2016 that was published in JAMA. “Unhealthy diet is a major risk factor for noncommunicable diseases globally, including type 2 diabetes mellitus, cardiovascular disease, and certain types of cancer. In the United States, poor diet was estimated to be the leading cause of death and the third leading cause of disability-adjusted life-year loss. Consequently, evaluation of overall population trends in diet is important to identifying challenges and opportunities for improving the diet of all US adults,” wrote co-author Fang Fang Zhang, MD, PhD, associate professor, The Gerald J. and Dorothy R. Friedman School of Nutrition Science and Policy, Tufts University, Boston, MA, and colleagues. For this serial, cross-sectional analysis, they used data from adults aged ≥ 20 years (mean age: 46.9 years; 51.9% women) from nine National Health and Nutrition Examination Survey (NHANES) cycles. Using 24-hour dietary recall data, they analyzed respondents’ dietary intake of macronutrients and food sources, and graded these with the Healthy Eating Index (HEI) 2015. Consider that to meet the caloric (or energy) demands of our bodies, we primarily consume three types of dietary macronutrients: protein, fat, and carbohydrate. In this study, however, nearly half (42%) of the respondents’ average daily caloric intake was found to consist of refined grains, starchy vegetables, and added sugars. Further, saturated fat intake comprised over 10% of daily calories, while only 9% came from whole grains and fruits. Here are some more findings from their analysis: Total carbohydrate intake declined by 2.02%, from 52.5% in 1999 to 50.5% in 2016 Total protein intake increased from 15.5% to 16.4%, while total fat intake went from 32.0% to 33.2% Intake of low-quality carbohydrates decreased by 3.25% (P < 0.001 for trend) High-quality carbohydrate intake increased by 1.23%, plant protein intake by 0.38%, saturated fatty acid intake by 0.36%, and polyunsaturated fatty acid intake by 0.65% (all P < 0.001 for trend) Intake of whole grains increased (0.65%) whereas the intake of added sugars decreased (-2.00%) Encouragingly, the estimated overall HEI-2015 increased by 2.01, from 55.7 to 57.7 (P < 0.001 for trend). The HEI measures adherence to the key recommendations outlined in the 2015-2020 Dietary Guidelines for Americans. Dr. Zhang and colleagues noted, however, that the “improvement in the HEI-2015 was small in magnitude and of uncertain clinical importance.” They also outlined the findings that are still problematic, including the fact that Americans still eat a disproportionally high quantity of low-quality carbohydrates from refined grains, fruit juice, and potatoes (21.2%), and added sugars in foods and beverages (14.4%) Further, Americans’ protein intake came mostly from eating animal foods, including unprocessed red meat and processed meat, instead of from seafood and plant sources. And US adults’ saturated fat intake is still above the recommended level of 10% from the Dietary Guidelines for Americans. Finally, they found that Americans of lower-income households and lower education levels demonstrated no improvements in overall diet quality and less improvement in macronutrient composition than those with greater incomes and higher education. “From 1999 to 2016, US adults experienced a significant decrease in percentage of energy intake from low-quality carbohydrates and significant increases in percentage of energy intake from high-quality carbohydrates, plant protein, and polyunsaturated fat. Despite improvements in macronutrient composition and diet quality, continued high intake of low-quality carbohydrates and saturated fat remained,” they concluded. Source
