Yes, but …
We have a long, long way to go
Two recent studies suggest that we Americans eat better today than we did 20 years ago. Researchers at Harvard used data from a nationally representative sample of 43,996 American adult participants in the National Health and Nutrition Examination Survey from 1999 to 2016. The Healthy Eating Index 2015 measured diet quality (carbohydrate, fat, and protein intake). Since 1999, intake of low-quality carbs (mostly added sugar) deceased, while intake of high-quality carbs (mostly whole grains) increased. Intake of plant protein (mostly whole grains and nuts) and polyunsaturated fat increased. Yet, 42 percent of energy intake came from low-quality carbs. Intake of saturated fat remained above 10 percent of energy intake. The overall Healthy Eating Index 2015 score increased from 55.7 to 57.7 (out of 100 possible points). Thus, overall diet quality increased slightly, but intake of low-quality carbs remained high and intake of saturated fat exceeded 10 percent, the widely recommended upper limit.
Has the relentless barrage of media messages over the past two decades encouraged America’s youth to eat better? A new study suggests that it has, albeit marginally. Researchers used data from 31,420 youth aged 2 – 19 years from the National Health and Nutrition Examination Survey. Three approaches estimated diet quality. First, the American Heart Association’s primary diet score. It reflects intake of total fruits and vegetables, whole grains, fish, shellfish, sugar-sweetened beverages, and sodium. Second, the American Heart Association’s secondary diet score. It includes the foregoing factors plus nuts, seeds, legumes, processed meat, and saturated fat. Third, the Healthy Eating Index 2015, which includes fish and shellfish, total fat, seafood omega-3 fatty acids, protein, carbohydrate, fiber, potassium, and calcium.
Diet quality scores were grouped into categories of ideal (80 percent or greater adherence), intermediate (40-80 percent adherence, and poor (less than 40 percent adherence). From 1999 to 2016, the diet quality of America’s children improved as measured by all the three approaches to diet quality. Based on the AHA primary diet score, the proportion of Americans in the poor category decreased from 76.8 percent to 56.1 percent. The proportion in the intermediate category increased from 23.2 percent to 43.7 percent. Sadly, the proportion of youth in the ideal category barely moved from near zero (0.07 percent) to slightly higher (0.25 percent).
Among the major food groups, consumption of whole fruits increased significantly, while consumption of vegetables did not increase. Whole grain intake increased markedly (but the whole grain category can include a sizeable component of refined grains). Fiber intake also increased significantly. Intake of both sugar-sweetened beverages and added sugar decreased significantly. Low parental education, low household income, and low household food security status all predicted lower diet quality. Older children had poorer diet quality than younger children, presumably reflecting marketing of processed and junk foods to adolescents. Overall, US diet quality improved over the past two decades, but only one (!) out of 400 American youths eats an ideal diet.