Functional MRI Brain Scans May Predict Weight Gain

April 18, 2012

If a patients shows strong response to images of food (or sex) in an fMRI, they are more likely to gain weight (or have more sex) in coming months, say researchers.

Functional MRIs of the brain that target the “reward center” may be able to predict weight gain, say researchers in a study published in the April 18 issue of The Journal of Neuroscience.

The researchers, from Dartmouth in Hanover, NJ, examined fMRI scans on a group of first-year college students. The subjects viewed images of animals, environmental scenes, appetizing food items, and people. Their weight was also recorded. Six months later, the subjects’ weight was recorded again, and they completed a questionnaire regarding their sexual behavior since the scan. This information was compared with the previously obtained images.

People who showed strong responses to food cues during fMRI were most likely to gain weight within those six months than the subjects who did not react strongly. Similar responses were present for sexual images and activity: strong reactivity to sexual images predicted sexual desire.

The responses to different images did not cross over and were “material specific.” They were clearly related to the images that were viewed. The subjects who responded to food images and subsequently gained weight did not engage in more sexual activity, and vice versa.

“This is one of the first studies in brain imaging that uses the responses observed in the scanner to predict important, real-world outcomes over a long period of time,” said Todd Heatherton, the Lincoln Filene Professor in Human Relations in the department of psychological and brain sciences and a coauthor of this study.