Genes and sensitivity to environmental cues both contribute to obesity, but the relationship between these two is not well understood. A recent paper published in PNAS shows that children who have a genetic predisposition for obesity have a different neurological response to food, as well as larger reward centers. These two findings suggest that at least some of the genetic predisposition for obesity works by altering brain structures that respond to food.
The study looked at children who have a genetic variant that has been associated with obesity risk. People with this genetic variant tend to have a high body fat percentage and BMI. Scientists suspect that the gene also influences food intake and choices, but not exercise habits. Based on previous work, the researchers behind the new paper theorize that this gene influences brain functions.
The authors recruited 78 children between the ages of nine and 12 for their study. These participants were all screened for the obesity-related genetic variant. Nineteen of the participants were considered high-risk because they had two copies of the variant. Thirty-seven had only one copy, and 22 did not have it at all; both of these groups were considered low-risk. The children were all asked to watch age-appropriate television that was interrupted with both regular and food-related commercials.