Hormones and Appetite

Your appetite is strongly influenced by biological factors. Ghrelin and leptin are two hormones that play an important role on appetite. Ghrelin is a hormone that increases appetite, or your desire to eat. To satisfy your body’s need for food, your brain stimulates the release of ghrelin through your stomach and endocrine glands when your stomach is empty. Ghrelin levels decline when you are full. Contrary to ghrelin, leptin suppresses hunger. However, obese people are often resistant to the appetite-suppressing effects of Leptin. Peptide YY is another hormone that suppresses hunger. However, obese people produce less peptide -- which further reduces their ability to suppress hunger and lose weight.

Effects of Exercise on Appetite

In addition to other health effects, physical exercise also affects the production of ghrelin and peptide YY -- appetite hormones. In a 2009 study published by the “American Journal of Applied Physiology,” researchers evaluated the effects of resistance training on hunger. The results showed that aerobic exercise decreases ghrelin levels and increases the release of peptide YY. However, weight training only lowered ghrelin levels, and peptide levels remained relatively unchanged. Moreover, physical exercise also facilitates weight loss by increasing the amount of calories you burn. Since leptin sensitivity and peptide YY levels increase as you lose weight, physical exercise may indeed help curb your appetite.

Other Ways to Reduce Appetite

Physical exercise is not the only method you can rely on to restrain your appetite. Simple and practical lifestyle changes, such as increasing fiber consumption, drinking more water and getting more sleep, may help you reduce your appetite. For example, a 2008 study in the “Journal of Sleep Research” showed that a single night of lack of sleep led to an increase in ghrelin levels. Water and dietary fiber make you feel full faster when you are eating.

Safety

While exercise has been proven to help you reduce calories, it is also important to have self control. Exercising too much without giving yourself time to recover leads to a condition known as overtraining. Although overtraining lowers appetite, it is bundled with unhealthy side effects, such as decreased athletic performance, headaches, muscle weakness and delayed recovery. If you are just starting, consider increasing activity incrementally. Make sure you're muscles are well rested before each exercise session.