The role of exercise in regulating appetite isn't well-understood, though, according to the American Council on Exercise, "the vast majority of studies have demonstrated that caloric intake is usually unchanged or slightly increased in response to long-term aerobic exercise training." So a lack of appetite that starts after beginning an exercise regimen might be something you should talk to your doctor about.
Lack of Appetite
The council says some research indicates that if you exercise vigorously before you eat, the increase in body temperature and alteration in your hormone levels might make you eat less. The body's temperature control, the thermoregulatory system, has its center in the brain stem right next to the centers that control appetite and sleep, which might be why these systems interact.
Dual-Process Effect
Another possibility is that your hunger increases while the amount of food you have to eat to satiate that hunger decreases. In other words, you are hungrier but your appetite requires less to feel satiated. This might feel to you as if it is a lack of appetite because you need to eat less. Evidence backing this dual-process theory appeared in an August 2009 issue of "The American Journal of Clinical Nutrition." Researchers found that study participants who exercised regularly had increased hunger but were satisfied more quickly by the foods they ate.
Overtraining
Exercising too much, or overtraining, can have an effect on your appetite. Overtraining occurs when you push your body too hard for too long. While your exercise regimen should be challenging, if it's excessively difficult, your body might react with a decreased appetite or gastrointestinal disturbances. If you think you might be overtraining, work with a personal trainer to design an exercise regimen that includes appropriate periods of rest so your body can recover between workouts.
Considerations
The only way to know for sure whether your lack of appetite is linked to your exercise regimen is to talk to your doctor. It could be that exercise affects you differently than most people or it could be that a separate medical condition is causing your lack of appetite. For example, cancer, pregnancy, certain medications, liver disease and many other conditions can cause decreased appetite. Your doctor will analyze your medical history and your typical diet, and perform any necessary tests to determine the cause of your decreased appetite.
References
- American Council on Exercise: Q. Does Aerobic Exercise Suppress a Person's Appetite? Some Experts Say It Does, Others Say It Doesn't. Who's Right?
- "The American Journal of Clinical Nutrition"; Dual-Process Action of Exercise on Appetite Control: Increase in Orexigenic Drive but Improvement in Meal-Induced Satiety; Neil A. King; August 2009
- American Council on Exercise; What Does Overtraining Mean?; Jessica Matthews
- MedlinePlus: Appetite -- Decreased
Member Comments