GAINESVILLE, Fla. Once heralded as a promising obesity treatment, the hormone leptin lost its fat-fighting luster when scientists discovered overweight patients were resistant to its effects. But pairing leptin with just a minor amount of exercise seems to revive the hormones ability to fight fat again, University of Florida researchers recently discovered.
The combination of leptin and a modest dose of wheel running prevented obese rats on a belt-busting, high-fat diet from gaining weight, even though neither tactic worked alone, say UF researchers, writing in the journal Diabetes.
They dont run enough to use sufficient energy to prevent weight gain, said Philip Scarpace, Ph.D., a professor of pharmacology and therapeutics in the UF College of Medicine and the senior author of the study. What the act of running appears to do is allow the leptin to work again. Its a demonstration that this simple act can reverse leptin resistance.
More than 34 percent of American adults about 72 million people are obese or overweight, according to the Centers for Disease Control and Prevention. Scientists had hoped to wield leptin, a hormone that sends the body chemical signals to stop eating and use stored energy, as a weight-loss weapon. Studies in lean animals were promising, but overweight animals and people dont respond the same way, likely because their bodies already overproduce leptin, causing them to develop resistance to the hormone, Scarpace said.
Obese animals and humans dont respond to leptin at all, he said. Our lab is interested in elucidating why this is the case. We know that often single-entity treatments are not successful. The concept was maybe a dual-entity treatment would work.
To test this, the researchers decided to pair leptin with exercise, comparing the effects on both normal-weight and obese rats kept on high-fat diets, which simulate the type of fast-food-filled fare many Americans eat.
|Contact: April Frawley Birdwell|
University of Florida