Q: Please tell me there is a way to interpret the new CDC research on kids gaining weight during the pandemic that isn’t just a diet culture freakout? Because that’s all I’m seeing online.
Back in January (so, four thousand pandemic-years ago) I wrote a piece for the New York Times Parenting section called “Should You Worry About Your Kid’s Pandemic Weight Gain?” And my answer—also the answer of every expert I interviewed, including a leading childhood ob*sity expert—was a resounding no. You should not worry if your child has gained weight in the past year, because obsessing over your child’s body size will never be helpful or health-promoting.
But in that piece, I also noted that another reason for parents not to worry was that, at that point, we didn’t even have any good data showing that kids really were gaining weight. It was hard to track kids’ weight during lockdowns, because most of them went to doctor’s offices a lot less, and got on scales a lot less. So all we really had was a lot of hand-wringing “experts” saying “oh God, this is going to make kids so fat!” Which was helpful, I guess, if your life in a global pandemic didn’t feel full enough of amorphous looming fear.
Well. We now have some data: The rate at which kids’ Body Mass Index scores increased did approximately double during the pandemic compared to pre-pandemic times, according to a new analysis by the Centers for Disease Control and Prevention of 431,302 kids aged 2 to 19. Kids who had BMIs in the “overweight” and “ob*se” ranges before the pandemic, experienced the biggest increases to their rate of growth. Translation: Kids are always growing, but they seemed to grow twice as fast during the pandemic, especially if they were big to start with.
Okay, so the data shows kids are gaining weight. So now do we panic? We do not.
For starters: “The CDC did not use a nationally representative data sample to conduct this analysis,” says Monica Kriete, MPH, an independent weight stigma researcher better known online as @fattyMPH. They couldn’t, for the same reason that we didn’t have this data when I first wrote about it in January: Not enough kids went to the doctor and got weighed in a systematic way in 2020. So instead of using data collected by government researchers at the National Center for Health Statistics (the usual and preferred source for this kind of research), this report analyzes data from a commercial entity called IQVIA, which tracked data collected at 800 “ambulatory sites” across the country. “But they don’t say what constitutes an ambulatory site,” notes Monica. “It could bias a sample pretty powerfully if, say, IQVIA contained data exclusively or mostly from commercial sites, like Minute Clinics and other chains instead of independent practices, and academic medical affiliate clinics.”
The data is also biased towards kids getting regular outpatient healthcare before and during the pandemic, because again, those are the only kids the researchers could track. “This has implications for socioeconomic status and health status,” Monica explains. “Going to in-person doctor appointments during Covid could reflect a need for more healthcare, or less concern about contracting Covid than families sticking with telehealth appointments. Or both or neither.” It is very difficult to have a nationally representative data sample from a year when our nation bisected itself in dramatic and health-determining ways.
Next, let’s deal with the fact that the CDC is using BMI as their measure of kids’ growth. The limitations of BMI as a tool for assessing health have been widely reported at this point; I have a brief sketch here, and dietitian Anna Lutz gave us a great breakdown of the particular problems with the CDC’s pediatric BMI charts in this audio newsletter. For an even deeper dive into the racist history of the BMI, I’ll send you to this Maintenance Phase episode and other work host Aubrey Gordon has done. (Also, stay tuned for my next book, which has a whole chapter on BMI and kids.) But for now, our important takeaway is that the CDC is using an imprecise and problematic instrument to measure growth in children. And, in addition to its many scientific failings, the BMI measures body size, not health, and not health-related behaviors. Kids getting bigger does not automatically mean kids getting unhealthier. “The CDC only collected data on height and weight; they didn’t ask any questions about behavior or health outcomes,” says Monica. “So they can’t really draw any conclusions about why this happened.”
Kids may well be less healthy right now—they have, after all, been surviving the stress of remote school, skyrocketing poverty and a global pandemic. But their worse health is not necessarily body-size driven. A larger body size often correlates to certain health outcomes, but we do not have evidence that it causes these health outcomes, as I explained here. And even if getting fatter is shown definitively to cause more asthma, more childhood diabetes, more of every bad thing for your kids that you can think of: We don’t have a safe and effective way for kids (or anyone!) to lose weight and keep it off. Childhood dieting is the number one predictor of future eating disorder risk, a fact we’ve known since 1999 when Australian researchers published the results of a three year study on almost 2,000 kids, which found that teenage girls who dieted “at a severe level” were 18 times more likely to develop eating disorders than those who did not. In that study, even kids who were “moderate dieters” were five times more likely to progress to an eating disorder. Subsequent research has replicated these findings repeatedly. Pursuing intentional weight loss for kids is also—irony alert!—a predictor of future weight gain, i.e. exactly the thing everyone is so upset about here.
Even in the new report, CDC researchers don’t advise pursuing weight loss in response to kids’ climbing BMI. Instead they write:
These findings underscore the importance of efforts to prevent excess weight gain during and following the COVID-19 pandemic, as well as during future public health emergencies, including increased access to efforts that promote healthy behaviors. These efforts could include screening by health care providers for BMI, food security, and social determinants of health, increased access to evidence-based pediatric weight management programs and food assistance resources, and state, community, and school resources to facilitate healthy eating, physical activity, and chronic disease prevention.
In other words: We should figure out better ways to keep kids healthy and well-fed during world-altering public health crises. Bold initiative, CDC! I like how you think! Actually, I don’t, because the CDC still thinks the best way to measure kids’ health is through their BMI, and with “pediatric weight management programs,” also known as diets for kids. But we’re on the same page with this idea of increasing access to food assistance resources. They love it because families experiencing food insecurity also tend to have the larger body sizes they’re so determined to prevent. (For more on the relationship between body weight and hunger, see my first book.) I’m more excited about getting through the next pandemic without 1 in 6 kids living in hunger. That would be nice. Maybe if we focused more on helping families pay their bills and afford food, and less on shaming poor kids for their size, we could get that done next time.
Now let’s talk some more about what the CDC researchers actually found. Kids in smaller bodies (BMI’s “normal weight” range) gained an average of less than half a pound a month on top of their predicted growth trajectories. Kids in bigger bodies gained an average of one to 1.2 pounds per month between March and November 2020. “Weight gain at this rate over 6 months is estimated to result in 6.1 and 7.3 pounds, respectively, compared with 2.7 pounds in a person with healthy weight,” the researchers wrote. But it’s not surprising that kids in bigger bodies grow faster than kids in smaller bodies because… that’s how bodies work. “Across all the weight categories, kids are gaining 1.5-2 times faster than they used to, but there’s no evidence that fatter kids are gaining disproportionately,” Monica explains. “There is no sense of perspective here about what these results mean.” Anna Lutz, who I also interviewed in my initial reporting on kids and pandemic weight gain, agrees: “This amount of weight gain may be statistically significant. But it’s ridiculous to call it ‘alarming.’” she says. “This is a natural response to the fact that the pandemic did change all of our lives.”
It’s also worth noting that the youngest and oldest kids saw little to no change in their rate of growth. Kids aged 6 to 11 had the greatest acceleration in growth, while kids aged 12 to 17 came in second. What else do kids in those age groups do? Go through puberty, the life stage where girls gain an average of 10 pounds per year for four years beginning anywhere from 8 to 10 years old (and boys have a similar growth spurt a few years later), as I reported for Parents. These are also the years when we see 25 percent of human growth in height. “If this weight gain had a behavioral cause—like school and sports disruptions due to the pandemic—we would expect it to be consistent across age groups,” says Monica. “This data points away from a behavioral cause and toward something fundamental about biology and stress.”
Driving the CDC’s analysis, as well as the anxious media coverage it has garnered, is, of course, fatphobia. “What’s not said, but strongly implied, is that this weight gain will just continue to go and go and go,” says Anna. “But we know that bodies adapt in all different ways to the circumstances they are in, without us trying to control them. What if we see those 2.7 to 7.3 pounds gained not as a failing, but as a survival response to a pandemic?” After all, the kids who gained weight are also, mostly, the kids who stayed home, stayed safe, and didn’t require hospitalization to treat a life-threatening virus. Of course, some kids stayed home without gaining weight—bodies respond to stress in a wide variety of ways, as I wrote last week. But there’s still no reason to pathologize the kids who did gain weight staying home, when staying home was the most adaptive and pro-health strategy we had at the time.
As kids return to school and sports this year, activity levels and eating habits will change and change again. We’ll see this most dramatically, of course, for kids with privilege: Parents who can afford to put their kids back into soccer or swim lessons are doing that. They also had, and continue to have, more resources to navigate the other pandemic health impacts, whether in terms of food access issues or mental health struggles. Instead, we’ll continue to see, as we’ve always seen, that “childhood ob*sity” disproportionately impacts kids in marginalized communities. “Part of what anti-fatness does is to scapegoat one kind of body to dismiss the material consequences of unacceptable social conditions,” says Monica. Kids in marginalized communities don’t need to weigh less; they need less marginalization. And one way to start doing that is to stop identifying a larger body size as the pandemic outcome that Nice White Parents most dread for our kids.
ALSO
The Not-A-Diet Diet: For Bustle, I dug into the promises and pitfalls of Noom, the dieting program that says it’s not a dieting program while telling users to restrict their caloric intake to 1,200 or 1,400 calories a day. Read the investigation here.
Body Language: I spoke to Bethany Brookshire about how weight stigma is bad for our health. I love that this piece is geared towards students! It’s a good one to share with any science-minded tweens/teens in your life. Read more here.
Coming up: On Thursday’s audio newsletter, I’ll be tackling reader questions like, “Is intentional weight loss always bad?” and “My daughter ‘binges’ on food and I don't know how much I should control this,” among others. Subscribe now so you can tune in: