A new study revealed that severe childhood obesity rates have risen in the United States — and experts expect to see the upward trend continue. 

Published in the journal Pediatrics, the study looked at 16.6 million children ages 2 to 4 who were enrolled in the Special Supplemental Nutrition Program for Women, Infants, and Children. 

This program “serves to safeguard the health of low-income pregnant, postpartum and breastfeeding women, infants and children up to age 5 who are at nutritional risk by providing nutritious foods to supplement diets, information on healthy eating including breastfeeding promotion and support, and referrals to health care,” according to the U.S. Department of Agriculture website. 

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The children in this test group were weighed and measured.

In 2010, research found that 2.1% of kids were considered severely obese. 

Severe obesity is defined as “sex-specific BMI for age ≥120% of the 95th percentile on the Centers for Disease Control and Prevention growth charts,” according to the authors of the study.

In six years, this number dropped from 2.1% to 1.8%, but in 2020, it saw a rise again at 2%. 

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Increases were seen in 20 states across the country, with California having the highest rate at 2.8%.

“We were doing well, and now we see this upward trend,” said one of the study’s authors, Heidi Blanck of the Centers for Disease Control and Prevention (CDC), per the Associated Press. “We are dismayed at seeing these findings.”

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The exact reason for this increase is unknown by experts.

The authors acknowledged the changes to daily routine during the COVID-19 pandemic, during which kids were home for most of the day with many disruptions, like lack of physical activity.

“We are thinking it’s going to get worse,” said Deanna Hoelscher, a childhood obesity researcher at the UTHealth Houston School of Public Health, per the Associated Press.

Childhood obesity can lead to many different health problems down the line. 

These include but aren’t limited to asthma, sleep apnea, bone and joint problems, type 2 diabetes and risk factors for heart disease, according to the CDC

While genetics is a factor in certain cases, there are many things parents can do with their children to combat childhood obesity. 

Parents can work to establish healthy eating patterns with their children, promote physical activity throughout the family, keep a good sleep routine as well as limit screen time as much as possible, according to the CDC.

The Associated Press contributed to this report.

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