Are you trying to lose those extra kilos around your waist by dieting? Listen to your brain first as weight loss is not merely a matter of willpower but is actually connected to much more basic visual and olfactory cues, researchers have found. The team from Ben-Gurion University of the Negev (BGU) discovered a neural sub-network of connected regions between the brain and gastric basal electric frequency that correlates with future weight loss based on connectivity patterns.

The findings, published in the journal NeuroImage, support a prevalent neural theory that people with an increased neural response to seeing and smelling food consistently overeat and gain weight. "To our surprise, we discovered that while higher executive functions, as measured behaviourally, were dominant factors in weight loss, this was not reflected in patterns of brain connectivity," said Gidon Levakov who led the study from the BGU Department of Brain and Cognitive Sciences.

The researchers identified a connection between the stomach basal electrical rhythm within the subnetwork and weight loss. That rhythm governs the gastric waves associated with hunger and satiety. They also found that the brain's "pericalcarine sulcus", the anatomical location of the primary visual cortex, was the most active node in this subnetwork. The team assessed 92 people during an 18-month lifestyle weight loss intervention.

Before the intervention, the participants underwent a battery of brain imaging scans and behavioral executive function tests. The participants' weight loss was measured after six months of dieting. The team found that the subnetwork of brain regions corresponded more closely to basic sensory and motor regions rather than higher, multi-modal regions. "It appears that visual information may be an important factor triggering eating," says principal investigator Professor Galia Avidan. "This is reasonable, given that vision is the primary sense in humans". The results may have significant implications toward understanding the cause of obesity and the mechanism of response to dieting.