Researchers across the country are reporting that pediatric obesity and a chronic condition that often goes with it, type 2 diabetes, have spiked since the start of the pandemic, particularly among Black, Hispanic, and low-income children.

The reasons seem clear.

“Efforts to reduce COVID-19 transmission have likely contributed to worsening pediatric obesity,” researchers from Children’s Hospital of Philadelphia wrote in Pediatrics in May. “Families with children have faced the difficulties of managing virtual schooling, limited physical activity, and increased reliance on heavily-processed and calorie-dense foods.”

But it is not clear how to undo the damage.

“Maybe they could lose the [pandemic] weight gain,” CHOP pediatrician Brian Jenssen, lead author of the study, said this week. “More likely, they may maintain the extra weight as they grow. The obesity epidemic was getting worse and worse even before the pandemic.”

CHOP has a huge network of urban, suburban, and semirural clinics. Researchers analyzed body mass index (BMI) data from 169,000 pediatric visits in 2019, the year before the pandemic, and 145,000 visits in 2020, when the pandemic’s grip was iron. The children were ages 2 to 17, with an average of 9.

The prevalence of obesity among CHOP patients rose from 13.7% to 15.4%, and the increases were more pronounced among Black, Hispanic, low-income, and publicly insured children — groups already disadvantaged by higher obesity rates. “This study suggests that during the pandemic, preexisting disparities in obesity ... widened,” the researchers wrote.

The CHOP study also found younger children, who are largely dependent on adults’ grocery shopping, cooking, and dietary choices, had the biggest increase in obesity prevalence.

“We were thinking it would be worst for teens,” Jenssen said. “But in our data, it was children aged 5 to 9 who were worst. Those children really do need the most support” from adults.

Much like adults, children with obesity or diabetes, or both, are at increased risk for severe COVID-19 if they get infected.

While the trends at CHOP are alarming, the national picture is likely worse. According to the latest federal survey data, collected a year before the pandemic, 19% of children and teens were obese. By age group, obesity affected 13% of 2- to 5-year-olds, 20% of 6- to 11-year-olds, and 21% of 12- to 19-year-olds.

Pre-pandemic studies have found that children tend to pack on pounds during the summer. That may seem counterintuitive for families that fill the warmer months with swimming, soccer camps, and sight-seeing. But for many children, summer — like the pandemic — means a hiatus from nutritious meals, gym classes, and team sports at school.

“We should not have been surprised by the pandemic effect, considering what we already know about summer weight gain,” Jenssen said.

Type 2 diabetes remains uncommon among children, but it is increasing. It is linked to obesity and caused by resistance to insulin, the hormone that regulates blood sugar. (Type 1 is an autoimmune disease, in which the body fails to produce insulin.) About 210,000 Americans under age 20, or 0.25% of that population group, have been diagnosed with diabetes, according to the American Diabetes Association.

» READ MORE: Type 1 diabetes rising among young children of color in Philadelphia

Because the pediatric disease is uncommon, small increases can be striking, as shown by two studies presented in June at the American Diabetes Association’s virtual meeting.

The first study, by Louisiana State University researchers, found that during the worst of the pandemic, from March through December 2020, 17 children admitted to a pediatric hospital in Baton Rouge were diagnosed with new-onset type 2 diabetes. That was just 0.62% of all admissions, but it was more than twice the number (8) during the same months in 2019. The average age of diagnosis also dropped by nearly a year, to 13.5.

The second study, at Children’s National Hospital in Washington, D.C., found that type 2 diagnoses nearly tripled from 50 before the pandemic to 141 during the pandemic. The severity of the disease at diagnosis, based on symptoms and treatment, also worsened.

Both studies found that Black males were the most likely to be newly diagnosed with the disease.

Yet another study, at Children’s Hospital Los Angeles, found the proportion of newly diagnosed children who had a life-threatening diabetes complication called ketoacidosis spiked from 3% to 20%.

“The exact reason for this increase [in ketoacidosis] is unclear,” the researchers wrote in the journal Diabetes Care. “‘Safer-at-home’ orders imposed because of the pandemic may have delayed patients and families from seeking medical care until the severity ... was dire.”

Recognizing that the pandemic has been a setback for childhood obesity, the American Academy of Pediatrics in December recommended ways that pediatricians can help families make healthier choices.

But CHOP researchers believe the pandemic has exposed “the need for larger policy changes” to fight obesity. For example, Jenssen said, the federal government subsidizes the production of corn, used to make high-fructose corn syrup, a key ingredient in obesity-promoting sugary drinks. To discourage consumption, the City of Philadelphia enacted a soda tax.

“We’re seeing this accelerated trajectory of obesity,” Jenssen said. “There may be [effective weight loss] medications that emerge, but we aren’t there yet. The solutions will likely have to be public health policies.”