Weight loss success not all behavioral, also linked to brain composition
The scientists found that people with an over-sensitivity to food cues - such as an increased neural response after seeing and smelling food - tend to overeat regularly and in turn gain weight.
By ZACHARY KEYSERAn image of the human brain(photo credit: REUTERS)
Researchers at Ben-Gurion University at the Negev (BGU) have discovered a neural subnetwork that corresponds to future weight loss.The scientists found that people with an over-sensitivity to food cues - such as an increased neural response after seeing and smelling food - tend to overeat regularly and in turn gain weight.The theory not that simplistic, however, the researchers found that the increased neural response to food cues also induces a gastric reaction - causing satiety and hunger - which accompanies the brain activity causing these individuals to give into their urges.To conduct their study, the researchers worked with 92 individuals over an 18-month period on a dietary intervention program. The study participants were obese individuals selected for their large waist circumference and abnormal level of blood lipids at their age.Before the program start, participants underwent fMRI brain imaging scans and behavioral tests to determine what a successful weight loss program would be for each individual.However, instead of finding a universal weight loss program, the researchers located a connection between the stomach basal electric rhythm within the neural subnetwork and weight loss.The rhythm dictates the movement of the gastric waves that cause hunger and satiety and the researchers found that within their study sample a good portion were overly sensitive to seeing and smelling food - so much so that it causes a deep gastric reaction within their bodies triggering the body to eat."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. In other words, weight loss is not merely a matter of willpower, but is rather connected to much more basic visual and olfactory cues," said BGU graduate student Gidon Levakov, who led the study from the Department of Brain and Cognitive Sciences at BGU.More so, the researchers found that visual food stimulation was the most likely component to activate this neural subnetwork and bring upon the urge to eat."It appears that visual information may be an important factor triggering eating. This is reasonable, given that vision is the primary sense in humans," said principal investigator Prof. Galia Avidan.Their complete findings have been published in the scientific journal NeuroImage.
