5 Appetite Hormones That Control How Much You Eat

August 28, 2011

by Cathe Friedrich

Your stomach is growling, and you can’t get your mind off of food. Hunger is a powerful motivator that sends you running to the kitchen for a meal or a snack. If you’re like most people, you have a good appetite. Maybe too good. But have you ever wondered what it is that motivates you to eat? Appetite hormones send signals to your brain to tell you to eat more or to stop eating. Here are the key appetite hormones that play a key role in how much you eat.

Leptin

Leptin is the best known of the appetite hormones. Leptin is produced by fat cells. It sends a signal to your brain to tell you to stop eating. Therefore leptin is a hormone that suppresses appetite. Some overweight and obese people have high leptin levels. If that’s the case, why don’t these high levels of leptin turn off their appetite?

Obese people can have leptin resistance where they no longer respond to the appetite-suppressing signals that leptin sends. Thus, they continue to eat even after their leptin levels rise. In contrast, thin people usually have low leptin levels, because they have fewer fat stores to produce it.

Ghrelin

Ghrelin has the opposite effect of leptin. It’s produced by cells in the stomach, and it stimulates rather than suppresses appetite. Normally ghrelin levels increase during fasting and decrease for about 3 hours after a meal. Ghrelin levels are reduced in people who are overweight or obese and higher in thin people and those with anorexia nervosa. Ghrelin and leptin levels are also affected by sleep. Ghrelin rises and leptin levels fall with sleep deprivation. This may explain why people who don’t get enough sleep snack more and often gain weight.

Cholecystokinin

CCK is a hormone produced by the small intestine that stimulates the release of digestive enzymes. It also functions as an appetite suppressant by binding to receptors in the brain that control the urge to eat. CCK release is greatest when you eat a meal that’s high in fat. It also slows down the rate at which the stomach empties, which helps to reduce appetite. The release of CCK after a meal higher in fat may explain why fatty foods are more satiating than carbs.

GLP-1

GLP-1 or glucagon-like peptide-1 is an appetite hormone that’s not as well understood as the others. It’s a hormone produced in the small intestines when you eat carbohydrates or fats. It works in partnership with CCK to slow down the rate of food digestion and reduce the desire to eat. These two appetite hormones are a powerful combination for suppressing appetite. Interestingly, a study showed that Korean pine nut extract stimulates the release of CCK and GLP-1. So if you want to get full quicker, add fresh pine nuts to your salad.

Adiponectin

Adiponectin is a hormone found in fat tissue that may one day be used to tackle the growing obesity problem. When researchers injected adiponectin into mice, the mice lost weight without a change in their appetite. Despite the fact that the mice continued to eat the same quantity of food, they still shed body fat.

Can the metabolism-boosting benefits of adiponectin be harnessed to help obese people lose weight? Hopefully, further research will provide the answer. Not surprisingly, people who are overweight have less adiponectin in their bloodstream than thinner ones.

Other Players

There are other hormones that play a role in appetite such as peptide YY, neuropeptide YY, insulin, and cortisol, but these five are some of the biggest players when it comes to turning on and off your appetite. Now you know what’s happening when hunger strikes.

References:

WebMD. “How Sleep Affects Your Weight”
Rejuvenation Science. “Satiety – Appetite Control”