A type of "good" fat, known as brown fat, is more active in leaner children, a new study suggests.
Researchers at Joslin Diabetes Center and Children's Hospital Boston used PET imaging data to document children's amounts and activity of brown fat, which, unlike white fat, burns energy instead of storing it.
"Increasing the amount of brown fat in children may be an effective approach at combating the ever increasing rate of obesity and diabetes in children," Aaron Cypess, MD, PhD, an assistant investigator and staff physician at Joslin and senior author of the paper, said.
In the study, researchers reviewed PET scans that had been conducted on 172 children ages 5 to 21 at Children's Hospital Boston.
Active brown fat was detected in 44 percent of the children, with the rate about the same for girls and boys. Children aged 13 to 15 had the highest percentage of detectable brown fat and the highest brown fat activity.
But in addition, body mass index (BMI) was correlated inversely with brown fat activity, meaning that the thinnest children had the highest brown fat activity.
While the 2009 study of adults showed brown fat was more active in cold weather, in keeping with its role of burning energy to generate heat, the new study in children showed outdoor temperature had no effect on brown fat activity.
The increase in brown fat activity from childhood to adolescence and its inverse correlation with obesity suggest brown fat may play a prominent role in paediatric metabolism, energy balance and weight regulation.
Cypess said the goal is to first search for nonpharmacological ways to increase brown fat activity, perhaps by setting indoor temperatures colder in homes where obese children live.
Perhaps certain foods could also play a role in increasing brown fat levels, he said. If not, the development of new drugs might be the answer, he added.
The findings were published in The Journal of Pediatrics.