If you exercise, you may need less food for your body and fewer calories to shed the pounds, new research indicates. A few hundred daily sprints of running probably make your waistline shrink and help ease hunger pangs, say scientists studying the impact of exercise on appetite.
The findings confirm what decades of public health advice already suggests: Walk briskly and keep your blood pressure low so you can burn more calories without feeling hungry. It’s just that the implications are more subtle than simply hearing more: When you feel full, your body burns less fat and your chances of gaining weight drop.
Dr. David Katz, director of Yale University’s Prevention Research Center, where the study was conducted, and colleagues analyzed data from almost 2,000 adults who underwent standard medical evaluations and had their body mass indexes calculated. The researchers wanted to know whether exercise helped in two ways: influencing a person’s metabolism and controlling the balance of a person’s satiety hormones, ghrelin and leptin. They wanted to know if exercise could keep your stomach fat from growing to make up for the calories you burn.
According to Katz, who presented the study at the American College of Sports Medicine’s annual meeting in San Diego, scientists don’t yet understand why exercise is so efficient in keeping a person satisfied. He suspects that exercise is causing gradual weight loss by causing blood to circulate more in the stomach, which gets the fuel needed to run your muscles, and relieving stress to the nervous system and to the brain.
If the researchers could track individuals over time to see how weight and appetite changes as they exercise, they could tell if exercise was tied to weight loss or an increase in appetite and perhaps pinpoint the calorie-burning mechanism that’s producing the satiety hormones. Eventually, they say, they want to be able to track appetite as a result of the effects of exercise and identify different kinds of exercise.
That might reveal more about the role of exercise on obesity, say Katz and his colleagues. “We may have something in our hands that could lead to an exciting new treatment strategy for obesity.”