Overweight? It May Be Just Body Chemistry

Ever had the munchies even after you just ate? That urge to snack may be due to an overactive chemical "feedback" system that regulates appetite, food intake, fat metabolism, and body weight. The chemical culprit is called the endocannabinoid (EC) system, and it's the latest target in medicine's battle of the bulge. We can't change the EC system, but we may be able to work around it by redirecting the cues that make us overeat.

The findings are in the February issue of Food and Fitness Advisor, a monthly newsletter from Weill Medical College of Cornell University.

"What many people have traditionally viewed as a lack of willpower could actually have a biochemical basis," says Louis J. Aronne, MD, director of the Comprehensive Weight Control Program at New York Presbyterian Hospital-Weill Cornell Medical Center.

Ever had the munchies even after you just ate? That urge to snack may be due to an overactive chemical "feedback" system that regulates appetite, food intake, fat metabolism, and body weight. The chemical culprit is called the endocannabinoid (EC) system, and it's the latest target in medicine's battle of the bulge. We can't change the EC system, but we may be able to work around it by redirecting the cues that make us overeat.

The findings are in the February issue of Food and Fitness Advisor, a monthly newsletter from Weill Medical College of Cornell University.

"What many people have traditionally viewed as a lack of willpower could actually have a biochemical basis," says Louis J. Aronne, MD, director of the Comprehensive Weight Control Program at New York Presbyterian Hospital-Weill Cornell Medical Center. "It's not just a matter of lack of willpower to stop eating, or of an obesity drug not working, but the body's counterbalancing mechanisms that stops people from losing weight."

When your EC system is activated, it increases hunger and decreases satiety, driving the desire for tasty food, says Dr. Aronne. He calls this the "feed-forward" mechanism. "When you eat a high-fat, high- carbohydrate food, it activates the endocannabinoid system, leading you to eat even more," he explains. "The endocannabinoid system interacts with other hormones to make you feel hungrier, increases body fat, and drives weight gain. We now know that the endocannabinoid system is overactive in obese people. In one study, obese women were found to have higher levels of endocannabinoids than lean women."

Munchie receptors

Endocannabinoids are akin to the active chemical (cannabinoids) in marijuana that triggers its effects, including the "munchies." There are cannabinoid receptors all over the body—including the brain, the gastrointestinal tract, and fat cells. When cannabinoid receptors are activated in the brain (in the hypothalamus), it stimulates appetite, leading to increased food intake, says Dr. Aronne.