American Youth: Eating Better, Growing Fatter

Youngster Demands Toasted Corn FlakesBeing certain sometimes means being certainly wrong. For decades now, we’ve assumed that childhood obesity is a problem that stems unhealthy eating. “One of the best strategies to reduce childhood obesity is to improve the eating and exercise habits of your entire family,” says the Mayo Clinic. But a new study in JAMA tells us that children are eating better now than they were 20 years ago. And yet, while the healthfulness of their diets improved, obesity soared.

How can it be that eating better did not prevent our children from growing fatter?

Improving Diet Scores

Junxiu Liu and colleagues used data from the NHANES surveys for 1999 through 2016. They calculated dietary quality for youth and children from two to nineteen years of age. Over that 17-year period, they found a 27 percent improvement in the primary diet scores based on American Heart Association criteria. The criteria include eating fruits and vegetables, whole grains, and so on. Health Eating Index scores also improved significantly. However, the improvement in this measure was 11 percent.

Over this same time period, obesity in children and youth went up by 33 percent.

Of course, these data are self-reported. Questions about the validity of self-reports for measuring diet quality suggest that systematic bias is possible. Maybe people are learning over time what they should be eating. Thus, they might skew their reports more toward that ideal over time.

Seeing What You Want in the Data

It’s funny, though, that the authors of this study gloss over their primary finding – improved dietary quality. Instead, they go with a glass-half-full narrative. Maybe diets improved, “but more than half of children still had poor-quality diets,” they conclude.

That yes/but story fits with the presumption that envelopes us. “Poor diet is a major contributor to chronic diseases, including diabetes, heart disease, stroke, cancers, and obesity,” write Liu et al. However, if a poor dietary quality is the major contributor to childhood obesity, why does obesity prevalence keep rising – even while dietary quality is improving?

It’s time to rethink our assumptions about obesity and nutrition. One possibility is that dietary quality is not as important for driving obesity rates up as many people assume. Or maybe we’re chasing the wrong measures of dietary quality.

What is clear, though, is that current assumptions and priorities are not working for reversing the trend in obesity. Better progress will require better, more objective thinking – along with genuine curiosity to find and test strategies that might work better.

Click here for the study by Liu et al.

Youngster Demands Toasted Corn Flakes, illustration by Mary Mapes Dodge / Wikimedia Commons

Subscribe by email to follow the accumulating evidence and observations that shape our view of health, obesity, and policy.


March 28, 2020

2 Responses to “American Youth: Eating Better, Growing Fatter”

  1. March 28, 2020 at 12:08 pm, David Brown said:

    Maybe what’s considered healthy isn’t? Excerpt: “Is a particular dietary recommendation harming people in the U.S.? For almost 20 years, scientists have been arguing over whether Americans and others on a typical Western diet are eating too much of omega-6s, a class of essential fatty acids. Some experts, notably ones affiliated with the American Heart Association, credit our current intake of omega-6s with lowering the incidence of cardiovascular disease. Others, which include biochemists, say the relatively high intake of omega-6 is a reason for a slew of chronic illnesses in the Western world, including asthma, various cancers, neurological disorders and cardiovascular disease itself.

  2. March 28, 2020 at 12:23 pm, Mary-Jo said:

    I know the N is large here, thus, I should accept the ‘validity’ of the conclusion that children’s nutrition is *modestly* better, but I just can’t accept it. Yes, I DO think children are eating MORE of everything, including fruits and veg and other wholesome foods, thus, in that sense, better, dare I say, *healthier*, but, most likely, more junk, too, which is notoriously left off in 24-hour recalls, even if 30,000+ are done.