In the moments before people begin to binge eat, they often feel some kind of negative emotion—from sadness to anxiety to loneliness. Does binge eating make them feel better? Why do some people have an urge to eat when they’re down while others don’t? New research released online last month investigates how the brain reacts to food when people with bulimia are experiencing negative emotion.
Researchers at UCLA gathered data on a small group of women with and without Bulimia Nervosa. They showed the women pictures of a chocolate milkshake or water and gave them tastes of both, all the while examining images of their brain using an fMRI.
Women with bulimia nervosa who reported experiencing negative emotion just before the experiment exhibited greater neural activation in their brains (putamen, caudate, and palladium) in anticipation of the milkshake. In other words, when a bulimic woman is sad, for example, her brain reacts strongly to the thought of drinking a milkshake.
The specific parts of the brain that were activated are associated with our “reward circuitry.” The authors suggest that a bulimic person’s brain may become conditioned to make a strong connection between experiencing a negative emotion and having a craving to binge. This means that, for women with bulimia, simply feeling sad can trigger the brain to crave food.
However, the brain did not react in the same way when these women actually tasted the milkshake, only when they saw the picture of it and anticipated drinking it. The authors suggest that this might help explain why it’s so hard for people with bulimia to resist temptation when they’re feeling down (e.g. staying away from a fast food restaurant with tempting signs). And at the same time, they aren’t satisfied with a few tastes and end up binging in an effort to feel as good as they had hoped at the first sight of the food.
The study is one of the first to examine images of the brain in women with bulimia. As a result, it’s a preliminary finding—the sample was small and nobody actually engaged in binge eating during the experiment.
Nevertheless, the study sheds light on how neural activity in the brain is related to why people may crave food when they’re feeling down, be unsatisfied by the first few tastes, and end up binge eating.