Exercise helps with weight control, but it may not be only because it burns calories and fat. New research shows exercise also helps with appetite control by changing how gut hormones are released after a meal and how your body responds to them. These changes decrease appetite and cause you to eat fewer calories.
Appetite Hormones and Exercise
Ghrelin is a hormone produced by cells in the stomach that stimulates the appetite. Researchers at Johns Hopkins University found rats that ran in a wheel experienced a more rapid decline in ghrelin levels when they ate a meal. Such a decrease in ghrelin levels should help to suppress appetite and prevent overeating.
After running in a wheel, they also had higher levels of a hormone called amylin in their bloodstream after eating. Amylin has the opposite effect of ghrelin. It reduces appetite and slows down the movement of food through the digestive tract, thereby causing a rat or human to feel full. In addition, these rats also had a greater response to another appetite-suppressing hormone called CCK after exercising and eating a meal.
What does this mean? Exercise alters the way hormones that control appetite are released. Another hormone that controls food intake is leptin. Leptin levels rise during fasting and starvation and decrease after a meal and when the body is well fed. Unfortunately, the cells of some overweight people are no longer sensitive to leptin, because their cells have built up a resistance to it. This means they don’t get the signal they’re full and keep right on eating. Vigorous exercise seems to boost sensitivity to leptin and reduce leptin resistance. That’s a good thing if you’re trying to control your weight.
What Type of Exercise Suppresses Appetite Best?
Exercise may not only burn fat, but it may also change how you respond to food by altering gut hormones and how your body responds to them. But which type of exercise suppresses appetite best, aerobic or strength training?
In one study carried out in the U.K, researchers found that a vigorous treadmill workout decreased ghrelin and increased levels of an appetite-suppressing hormone called peptide YY. A weight-lifting session only lowered ghrelin levels but didn’t change peptide YY levels. When they questioned the participants after their workout, they felt less hungry after both types of exercise, but their appetite was suppressed more after the treadmill workout than the weight lifting one.
What Does This Mean?
Exercising, particularly vigorous aerobic workouts, not only burn calories and fat, they alter levels of gut hormones in a way that keeps you from feeling hungry afterward. Exercise helps to burn off the calories that you eat, and it may keep you from consuming too many afterward. Such is the power of a good workout.
References:
Medical News Today. “Exercise May Help Regulate Body Weight By Influencing Gut Hormones Released Before and After Meals”
Science Daily. “Exercise Suppresses Appetite By Affecting Appetite Hormones”
