Scientists Predict Weight Gain and Sexual Activity by Peeking at the Brain

  • Share
  • Read Later
Peter Cade / Getty Images

It sounds a bit like science fiction, but a group of researchers from Dartmouth College were able to observe students’ brain activity to predict their future behavior.

In the study, the researchers used functional magnetic resonance imaging (fMRI) to scan the brains of 58 incoming first-year college females. Before the scan, the women were weighed and told it was part of standard procedure. While in the scanner, the participants viewed a variety of images — of animals, the environment, appetizing food and people — and were asked to press a button if a person was present in each photo. The students were naive to what the researchers were really studying, which was the activity in an area of their brain called the nucleus accumbens, also known as the “reward center.”

(MORE: To Keep Willpower from Flagging, Remember the F Word: Fun)

The researchers looked at the nucleus accumbens in order to analyze the strength of the students’ brain responses to food-related or sexual images. Six months later, the same participants returned and filled out questionnaires detailing their sexual behavior in the interim and had their weight recorded again. These data were then compared to their previously recorded weight and brain scan results.

“The people whose brains responded more strongly to food cues were the people who went on to gain more weight six months later,” said study author Kathryn Demos, now a research faculty member at the Warren Alpert Medical School of Brown University, in a statement.

A similar association was also seen for sexual images and sexual activity. “Just as cue reactivity to food images was investigated as potential predictors of weight gain, cue reactivity to sexual images was used to predict sexual desire,” the authors say in the study.

(MORE: Mind over Mind? Decision Fatigue Saps Willpower — if We Let It)

What was particularly telling was that the cue responses and subsequent behaviors were specific. “Some people find food cues particularly rewarding and that causes weight gain, but some people are more sensitive to sexual images and that predicts their behavior down the road,” says study author Bill Kelley, an associate professor of psychological and brain science. Those who were more sensitive to sexual images did not report weight gain after seeing food images and vice-versa, the authors note.

The big take-home message is that our responses to reward cues are automatic and happen without our even being aware they are influencing our behaviors. That’s where being mindful of self-regulation or willpower can come into play. “Knowing certain cues are affecting you can make you more aware of them, and perhaps you can use your self-regulation system to keep things in check,” says Kelley — like not letting yourself automatically reach for a second slice of birthday cake.

(MORE: The Secrets of Self-Control: The Marshmallow Test 40 Years Later)

The researchers hope their study will contribute to the understanding of how our self-regulation system works and how our responses to reward can be controlled. “In the long-term, hopefully we can predict who are going to be the good self-regulators and we can study what we can do to teach a bad self-regulator to become a good self-regulator,” says Kelley.

The study was published in The Journal of Neuroscience.

MORE: The Key to Health, Wealth and Success: Self-Control

MAGAZINE: Getting to No: The Science of Self-Control

0 comments
Sort: Newest | Oldest