Medical expert of the article
New publications
Obesity suppresses the parts of the brain responsible for willpower
Last reviewed: 30.06.2025
All iLive content is medically reviewed or fact checked to ensure as much factual accuracy as possible.
We have strict sourcing guidelines and only link to reputable media sites, academic research institutions and, whenever possible, medically peer reviewed studies. Note that the numbers in parentheses ([1], [2], etc.) are clickable links to these studies.
If you feel that any of our content is inaccurate, out-of-date, or otherwise questionable, please select it and press Ctrl + Enter.
A new study by scientists from Yale University (USA) has shown the influence of the brain on the willpower to lose weight in overweight people.
A person predisposed to obesity who is trying to lose weight may encounter resistance from their own brain. Scientists claim that in this category of people, the “glucose meter” in the brain breaks down. In this condition, the volitional center in the cortex is suppressed, which leads to an uncontrollable desire to eat.
Normally, eating food causes blood glucose levels to rise, which is a signal to the brain and blocks the food reward center, which leads to a feeling of satisfaction from eating. In overweight people, the brain's reward center does not respond to blood glucose levels, and, unfortunately, does not turn off.
The study involved 9 people with normal body weight and 5 with excess weight. All participants were shown pictures of food (French fries, cauliflower, salad and ice cream). People had to assess their feeling of hunger, as well as the amount and types of food they would like to eat. The test was repeated several hours after eating.
But this time, some participants had their glucose levels artificially lowered from the background level (9 mg/l) to 7 mg/l by injecting insulin. As a result, the subjects began to feel hungry, and they wanted to eat high-calorie food. An MRI study of the brain showed increased activity in the insular zone and the striatum, which are responsible for the feeling of satiety and satisfaction from food. The volitional center of the cerebral cortex, responsible for making decisions not to eat too much, was sharply suppressed.
The results show that the sensitivity of the brain areas responsible for the feeling of satisfaction from food in overweight people is, for unknown reasons, reduced, which leads to the desire to eat, regardless of the amount eaten.
[