The rate of childhood obesity in the U.S. has tripled over the past 50 years. But what this trend means for children's long-term health, and what to do about it (if anything), is not so clear.

The American Academy of Pediatrics (AAP) made waves this year by recommending that doctors put obese kids as young as two years old on intensive, family-oriented lifestyle and behavior plans. It also suggested prescribing weight-loss drugs to children 12 and older and surgery to teens 13 and older. This advice marks a shift from the organization's previous stance of “watch and wait,” and it reflects the AAP's belief that obesity is a disease and the group's adoption of a more proactive position on childhood obesity.

Yet the lifestyle programs the AAP recommends are expensive, inaccessible to most children and hard to maintain—and the guidelines acknowledge these barriers. Few weight-loss drugs have been approved for older children, although many are used off-label. They have significant side effects for both kids and adults. And surgery, while becoming more common, has inherent risks and few long-term safety data—it could, for instance, cause nutritional deficits in growing children. Furthermore, it's not clear whether interventions in youngsters help to improve health or merely add to the stigma overweight kids face from a fat-phobic society. This stigma can lead to mental health problems and eating disorders.

Rather than fixating on numbers on a scale, the U.S. and countries with similar trends should focus on an underlying truth: we need to invest in more and safer places for children to play where they can move and run around, climb and jump, ride and skate.

Moving more may not prevent a child from becoming overweight, but studies show clearly that it helps both physical and mental health. In 2020 the Centers for Disease Control and Prevention found, unsurprisingly, that kids' sports participation increases with their parents' incomes: about 70 percent of kids whose families earn more than $105,000 a year participate in sports, but only 51 percent of middle-class kids and 31 percent of children at or below the poverty line do. This disparity hurts people of color the most. More than 60 percent of white children, for instance, participate in athletics, but only 42 percent of Black children and 47 percent of Hispanic children do. Experts blame these problems on the privatization of sports—as public investment in school-based athletics dwindles, expensive private leagues have grown, leaving many kids out.

According to the U.S. Department of Health and Human Services' Physical Activity Guidelines for Americans, children between ages six and 17 should get at least an hour of moderate to intense physical activity every day. Yet only 21 to 28 percent of U.S. kids meet this target, two government-sponsored surveys found. The nonprofit Active Healthy Kids Global Alliance evaluates physical activity in American children, and in 2022 the group gave the U.S. a grade of D–.

Why is it so hard to get kids moving? In addition to fewer opportunities at school, researchers cite increased screen time, changing norms around letting kids play outdoors unsupervised, and a lack of safe places for them to play outside the home.

New York City, for example, had 2,067 public playgrounds as of 2019—a “meager” amount for its large population, according to a report from the city comptroller—and inspectors found hazardous equipment at one quarter of them. In Los Angeles in 2015, only 33 percent of youths lived within walking distance of a park, according to the L.A. Neighborhood Land Trust. Lower-income neighborhoods tend to have the fewest public play spaces, despite often having a high population density. And although rural areas have more undeveloped outdoor space, they often lack playgrounds, tracks and exercise facilities.

Kids everywhere need more places to play: trails, skate parks and climbing walls, gardens and ball fields, bike paths and basketball courts. Robust public funding to build and keep up these areas is crucial, but other options such as shared-use agreements can make unused spaces available to the public. Only 10 percent of U.S. schools let people into their playgrounds and schoolyards when school's out, the Trust for Public Land found, and opening up these spaces would give 5.2 million more children access. “Play streets”—residential streets or parking lots that are temporarily closed for activities—are another affordable way to give kids more chances to run around.

These opportunities aren't primarily about changing children's waistlines—they're how we keep childhood healthy and fun.