August 20, 2019

WW, formerly named Weight Watchers, has launched a new diet app for children, but Christy Harrison, a registered dietitian nutritionist, in a New York Times opinion piece argues that parents should keep their children away from the app—and diets in general.

The best diets for 2019, according to US News

The new WW app for kids

WW describes its new weight-loss app for kids, Kurbo, as a "holistic tool," not a diet, Harrison explains.

The app works by encouraging children to track their food intake "using a 'traffic light' system that divides foods into red, yellow, and green categories," Harrison writes.

While WW's fine print says that weight loss results will "vary by age, weight, and height," Harrison explains that "the way [the app has] been branded doesn't change the effect it could have on its users." She continues, "Programs like this are fertile ground for disordered eating … implicitly coding certain foods as 'good' and others as 'bad.'"

What the research says about weight loss in kids

"Our society is unfair and cruel to people who are in larger bodies, so I can empathize with parents who might believe their child needs to lose weight, and with any child who wants to," Harrison writes. But in most cases, "attempts to shrink a child's body are likely to be both ineffective and harmful to physical and mental health," Harrison explains.

Namely, she points to research that shows that 90% of people who lose weight eventually gain it back. One 2015 study, for instance, found that 95% to 98% of people age 20 and older who lost weight gained it all back within five years.

While there's less data on the effectiveness of weight loss in kids, "the evidence we do have in this population suggests that long-term weight loss is just as unlikely for children," Harrison writes.

One 2017 systematic review of studies of weight-loss programs for kids between ages six and 11 found that weight-loss interventions produced "only small, short-term reductions in weight," and that the study had a very high risk of bias and low-quality evidence.

Further, Harrison notes that part of the reason for the lack of evidence is "because weight loss wasn't widely recommended for minors until fairly recently."

The health risks of dieting in children

In sum, Harrison asserts that "trying to shrink children's … bodies" is not only ineffective but "can put their health at risk."

One reason is "because intentional weight loss is likely to result in weight cycling—the repeated cycles of weight loss and regain commonly known as yo-yo dieting," Harrison writes.

Weight cycling has its own risks, Harrison writes. People who weight cycle are at higher risk of high blood pressure, chronic inflammation, and mortality, she notes.

"While these conditions typically get blamed on weight itself, in reality weight cycling accounts for at least some of the additional risk that comes with being at a high BMI," Harrison writes. "In fact, weight cycling may explain all of the excess mortality risk seen in people at the high ends of the BMI spectrum," Harris notes.

Dieting also exposes children to "anti-fat bias," also known as "weight stigma," which has been linked to an increased risk of Type 2 diabetes, hypertension, cardiovascular disease, and mortality as well as depression and anxiety, Harrison writes.

Another effect of dieting on people of all ages is disordered eating.

"It's especially common for kids to interpret even the most seemingly benign messages about 'healthy eating' in strict ways," Harrison writes. "Most of the clients I've treated for eating disorders … had their disorders triggered or exacerbated by messages they learned about food and weight in childhood," she adds.

Rather than encouraging dieting, parents can help children by using "intuitive eating," which refers to "getting back in touch with your body's innate cues about what, when and how much to eat," Harrison writes. She is the author of a forthcoming book on the topic. According to Harrison, several studies have shown the practice to be "linked to better health outcomes than even the most 'flexible' diet."

Harrison concludes, "If we truly want to help children be the healthiest and happiest people they can be, we need to stop putting them on diets of any kind." Instead, "[W]e need to help them make peace with their bodies, at any size" (Harrison, New York Times, 8/18).

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