Weight loss not just about willpower: It hinges on your brain’s response to sights and smells

BEER-SHEVA, Israel — Could a blindfold be the key to weight loss? Researchers in Israel say your ability to keep the pounds off doesn’t just come down to your willpower. A study of the brain finds what a person can see and smell plays a major role in overeating.

A team from Ben-Gurion University of the Negev (BGU) have discovered a subnetwork in the connection between the brain and the gastric basal electric frequency. This frequency of rhythmic waves controls when you’re hungry. The neural subnetwork they found has brain connections to a person’s vision and sense of smell.

The study theorizes that people who have higher neural responses to seeing and smelling foods are more likely to gain weight by overeating.

“To our surprise, we discovered that while higher executive functions, as measured behaviorally, were dominant factors in weight loss, this was not reflected in patterns of brain connectivity,” says Gidon Levakov from the BGU Department of Brain and Cognitive Sciences in a media release.

“Consequently, we found that weight loss is not merely a matter of willpower, but is actually connected to much more basic visual and olfactory cues.”

Is vision the biggest key to weight loss?

The Israeli team found a connection between the rhythms inside of this brain network and the ability to lose weight. In particular, their study reveals the brain’s pericalcarine sulcus is most active within the subnetwork. The pericalcarine sulcus marks the home of a human’s primary visual cortex.

Researchers examine 92 participants over 18 months. Each person was chosen based on their larger than normal waist circumference, abnormal blood lipid levels, and age. Before beginning their weight loss project, each participant underwent a series of brain scans and behavioral tests. The team then measured each subject’s weight loss success after six months, which study authors say is usually the peak time in any dieting program.

The results reveal a strong tie between the brain’s subnetwork controlling hunger and basic sensory regions. This link was higher than the subnetwork’s connection to other, more complex regions.

“It appears that visual information may be an important factor triggering eating,” principal investigator Prof. Galia Avidan says. “This is reasonable, given that vision is the primary sense in humans.”

The team says this may go a long way to understanding the causes of obesity and how to maximize a person’s dieting program.

The study appears in the journal NeuroImage.