High-level brain functions play a major role in weight loss, according to a new study published in the journal Cell Metabolism.
In a study of 24 patients at a weight-loss clinic, those who achieved greatest success in terms of weight loss demonstrated more activity in the brain regions of the lateral prefrontal cortex associated with self-control.
Alain Dagher, the study’s lead author, said: ‘What we found is that in humans, the control of body weight is dependent largely on the areas of the brain involved in self-control and self-regulation. That area of the brain has the ability to take into account long-term information, such as the desire to be healthy, in order to control immediate desires.’
Two hormones, leptin and ghrelin, are known to trigger the body to eat in a weight-loss setting. Previous research confirms that these hormone levels change rapidly when weight is shed.
To assess the roles these hormones and self-control have in achieving weight loss, the researchers studied 24 subjects from a weight-loss clinic. Prior to starting a standard 1,200 kcal/day weight-loss diet, all participants received a functional MRI study of the brain, which assessed regions including the lateral prefrontal cortex, which is linked with self-regulation, and the ventral medial prefrontal cortex, a brain area involved in motivation, desire, and value.
Subjects were shown pictures of appetising foods as well as control pictures of scenery. The researchers compared the brain activity response to the food pictures, particularly the high-calorie food pictures, for each subject at baseline, one month, and three months.
During the study, researchers noted that at one month and three months, the signal from the ventral prefrontal cortex went down, and it declined the most in people who were more successful at losing weight. Additionally, the lateral prefrontal cortex signal involved in self-control increased throughout the study.
‘These results suggest that weight loss treatments that increase self-control, such as cognitive behavioural therapy, may be helpful, particularly when stress is involved in leading to overeating. Stress disrupts the lateral prefrontal cortex control mechanism, but you may be able train people to seek a different strategy,’ Dagher says.