In a 2016 analysis of data from 18,000 kindergarten and elementary students, Workman, the education sociologist, calculated that their obesity rate increased by 0.85 percent every month they were out of school, or roughly 2 to 3 percent per summer. The students lost some weight when they returned to classrooms, but not enough to reverse the summer gains. Overall, the obesity rate rose more than 1 percent every calendar year.
This year, he projected the health impact of the pandemic by doubling that out-of-school time. According to his estimates, five months of school closures would raise the childhood obesity rate in America by 4.25 percentage points. That figure does not account for the fact that many childrens out-of-school time has in fact quadrupled. Nor does it consider the impact that pandemic-induced food insecurity may have on weight gain. For those reasons, the projection, however staggering, is likely a conservative one.
That is kind of a baseline of what we might expect, given the best of conditions, Workman said. But then you have the additional context of the pandemic, which I think would probably push it even higher than a normal summer break being doubled.
But it wont be all children who gain that weight. Andrew Rundle, a Columbia University epidemiologist, points to studies that show children of color tend to gain more weight during the summer than their white counterparts. The summer, he said, is when their weight gain tracks diverge, before realigning and running parallel again during the school year. Over time, those bumps add up, and drive permanent disparities between the groups.
For that reason, he expects the pandemic, insofar as it resembles the summer, to worsen the divide. According to the most recent data from the Centers for Disease Control, nearly 22 percent of Black children and 26 percent of Latinx children were obese before the pandemic, compared to 14 percent of white children. The new rates cant be known until after children return to schools, Rundle said. But no matter the numbers, its almost certain that the pandemics health impacts will be unequal.
We know what happens during a normal summer, and were arguing that this is equivalent to a completely abnormal summer that is three or four times longer than a regular summer, Rundle said. Anything I say about how big that difference will be is a complete guess. But if you look at the trends, and think through what the drivers are, youre going to expect a magnification of these disparities.
Researchers are confident that obesity rates have risen during the pandemic, but the long-term trends remain unclear.
Ohri-Vachaspati, the nutrition professor, knows from research like Workmans that childrens weight does tend to drop, however slightly, during the school year. But, she predicts, the length and duration of the pandemic summer likely means a permanent, long-term hike. In two years, she predicts, our hypothesis is that the obesity rates will be higher than they are today. Even if the weights start to come down, they will not come down to the pre-pandemic area, she said.
Of course, thats just her hypothesis. Workmans analyses of summer weight gain are based on studies of elementary students; what happens to middle and high schoolers during the summer isnt as clear. Schools have never been closed this long, and this extended period of heightened food insecurity may result in changes that no one can foresee. Still, its likely that when the pandemic ends, schools and communities will need concerted efforts to counter the obesity trends that worsened while students were stuck at home.