The way some people’s brains respond to food rewards may explain why they have a hard time not finishing the whole bag of chips or bowl of candy, new research shows.
In a study with children, researchers found that when certain regions of the brain reacted more strongly to food rewards than money, those children were more likely to overeat, even when the child wasn’t hungry and regardless of if they were overweight or not.
Shana Adise, a postdoctoral fellow at the University of Vermont who led the study while earning her doctorate at Penn State, says the results give insight into why some people may be more prone to overeating than others. The findings may also give clues on how to help prevent obesity at a younger age.
“If we can learn more about how the brain responds to food and how that relates to what you eat, maybe we can learn how to change those responses and behaviour,” Adise says. “This also makes children an interesting population to work with, because if we can stop overeating and obesity at an earlier age, that could be really beneficial.”
Previous research on how the brain’s response to food can contribute to overeating has been mixed. Some studies have linked overeating with brains that are more sensitive to food rewards, while others have found that being less sensitive to receiving food rewards makes you more likely to overeat.
Additionally, other studies have shown that people who are willing to work harder for food than other types of rewards, like money, are more likely to overeat and gain weight over time. But the current study is the first to show that children who have greater brain responses to food compared to money rewards are more likely to overeat when appealing foods are available.
“We know very little about the mechanisms that contribute to overeating,” Adise says. “The scientific community has developed theories that may explain overeating, but whether or not they actually relate to food intake hadn’t yet been evaluated. So we wanted to go into the lab and test whether a greater brain response to anticipating and winning food, compared to money, was related to overeating.”
For the study, 59 children between the ages of 7 and 11 years old made four visits to the Penn State’s Children’s Eating Behaviour Laboratory.
During the first three visits, the children were given meals designed to measure how they eat in a variety of different situations, such as a typical meal when they’re hungry versus snacks when they’re not hungry. Researchers determined how much the children ate at each meal by weighing the plates before and after the meals.
On their fourth visit, the children had MRI scans as they played several rounds of a game in which they guessed if a computer-generated number would be higher or lower than five. They were then told that if they were right, they would win either money, candy, or a book, before it was revealed if they were correct or not.
The researchers found that when various regions of the brain reacted more to anticipating or winning food compared to money, those children were more likely to overeat.
