When kids watch TV, they are inundated with commercials for fast food restaurants.
While many children ignore the commercials, others respond to them quite strongly, with each 30-second or one minute ad intensifying cravings for hamburgers, french fries and milkshakes.
Researchers are now discovering that the children who respond most to those commercials are those who have a genetic predisposition to obesity.
It’s a one-two punch that could contribute to a lifetime of unhealthy eating.
For the new brain imaging study, researchers at Dartmouth College found that children with a genetic risk for obesity had greater activity in brain reward centers when watching fast food commercials.
This may help explain why some children are more likely to overeat, the researchers claim.
“By examining the still-developing brain and its reward-related structures, our findings help explain why children who are genetically at-risk for obesity may be prone to overeating unhealthy foods,” said Kristina M. Rapuano, a graduate student in the Brain Imaging Lab in the department of Psychological and Brain Sciences at Dartmouth College.
Fast food advertisements were used for this study to better approximate how the brain responds to food cues in the real world, the researchers said, noting that most previous studies have shown only photographs of food.
For the study, 78 children between the ages of 9 and 12 watched a children’s television show in an MRI scanner. The show included 12 minutes of commercial breaks. Half were advertisements for fast food and the other half for non-food items.
Children were also evaluated on their genetic risk for obesity based on the fat-mass and obesity-associated (FTO) gene, which strongly predicts obesity across the lifespan, the researchers noted.
What the scientists discovered is that the nucleus accumbens, a region in the brain commonly associated with reward craving, was not only physically larger in children with the obesity-risk FTO genotype, but also showed a stronger craving response to the food commercials.
“About one-third of commercials children see on network television are food advertisements, and each one is a prompt to eat,” said Diane Gilbert-Diamond, an assistant professor of epidemiology at Dartmouth’s Geisel School of Medicine and member of the Norris Cotton Cancer Center. “We know from our prior work that children with this same genetic obesity risk factor are more likely to overeat after watching food advertisements on TV, even when they are not hungry. The brain scans suggest that these children may be especially vulnerable to food cues, and that limiting food advertisement exposure could be an effective way to combat child obesity.”
It makes sense — turn off the TV and turn off those cravings. It’s a simple way for parents to help their children be the healthiest they can be.