Less obesity in 3- and 4-year-olds after the pandemic, Swedish study finds

The study, published in the journal JAMA Pediatrics, is based on data on 50,833 children aged 3-5 years. Healthcare data about the children are sourced from regular check-ups at pediatric healthcare centers, BVC. Participating regions were Dalarna, Jönköping County and Sörmland.

The researchers have previously been able to demonstrate increased overweight and obesity during the pandemic among 3- and 4-year-olds in Sweden. According to the current study, today's 3- and 4-year-olds are at about the same levels as 3- and 4-year-olds before the pandemic. The group of 5-year-olds has not had similar weight changes.

The studied time periods are before the COVID-19 pandemic (up to and including April 2020), early pandemic (May 2020-May 2021), late pandemic (June 2021-March 2022) and post-pandemic (from April 2022).

Increasing and decreasing BMI

In the group of 3-year-olds, the proportion with obesity increased from 2.4 percent before the pandemic to 3.4 percent during the early pandemic, and then decreased to 2.3 percent during the late pandemic. After the pandemic, the proportion of 3-year-olds with obesity was 2.6 percent.

The development of overweight in 3-year-olds follows the same pattern. The proportion of overweight children went from 11.6 to 13.2 percent, followed by a decline to 11.3 during the late pandemic. After the pandemic, the proportion of overweight 3-year-olds was 11.9 percent.

In the group of 4-year-olds, BMI (body mass index) also changed significantly. The obesity rate increased from 2.6 percent before the pandemic to 3.7 percent during the early pandemic, then declined to 3.1 percent during the late pandemic and to 2.5 percent after the pandemic.

The proportion of overweight in the group of 4-year-olds rose from 10.3 percent before the pandemic to 11.7 percent during the early pandemic, and then decreased to 9.9 percent during the late pandemic and after the pandemic.

Unhealthy weight can regress

Globally, weight gain in young children during the pandemic has been explained by changes in dietary habits and reduced physical activity as a result of social restrictions and closed preschools. In Sweden, preschools were up and running, but the weight trend remained the same as in other countries, which, according to the researchers, may be due to the fact that many children missed out on nutritious food and regular outdoor activity.

The fact that the weight trend has now been broken is also of great importance in the long term. Childhood obesity increases the likelihood of continued obesity in adulthood, with an increased risk of cardiovascular disease, cancer, and lower quality of life.

Responsible for the study are Anton Holmgren, Pediatrician at Halland Hospital, who conducts research in pediatrics at Sahlgrenska Academy, University of Gothenburg, and Anna Fäldt, Researcher at Uppsala University within pediatric health and parenthood.

"The fact that the proportion of overweight and obese 3- and 4-year-olds has decreased indicates that the weight gains were related to the pandemic, and that an unhealthy weight status can be reversed. This also applies at the individual level, a significant proportion of the children where we had repeated measurements dropped to a lower BMI class after the pandemic," says Anton Holmgren.