Gut-brain connection sheds light on how overeating leads to obesity

Consuming more calories than is needed for energy leads to obesity, but the question of what triggers it has remained obscure for decades. Now a new study led by researchers at Baylor College of Medicine has found a previously unexplored gut-brain connection that explains how excessive intake of food leads to weight gain.

Overeating or consuming high fat-diet increases the levels of gastric inhibitory polypeptide (GIP) in blood, a hormone in the gut that helps manage body’s energy balance. When the excess of GIP travels through the blood to the brain, it hinders the action of leptin – a “satiety hormone” that makes you feel full – and hence you continue eating, putting on more weight.

Leptin is produced by fat cells, and its role is to signal hypothalamus that we have eaten enough and to stop. But in case of obesity resulting from overeating, the brain stops responding to leptin.

Reinvigorating the brain’s ability to respond to leptin signals by suppressing the anti-leptin effect of GIP could one day be translated into weight loss strategies, the researchers say.  

Reference: Gut-derived GIP activates central Rap1 to impair neural leptin sensitivity during overnutrition (Journal of Clinical Medicine) / Baylor College of Medicine