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Sept. 9, 2010 -- Weight regain is the bane of many a dieter's existence. Often dieters who regain weight after losing it are viewed as failures and judged for their lack of willpower, but new research may put an end to this blame game.
Weight regain may not be solely a willpower issue. Some people may actually be programmed to gain weight back based on their levels of two key appetite hormones, leptin and ghrelin. The new study appears in an online version of the Journal of Clinical Endocrinology & Metabolism.
"This knowledge could be used as a tool to personalize weight-loss programs that could guarantee success in keeping off the weight," says study author Ana Crujeiras, PhD, of Compejo Hospitalario Universitario de Santiago in Spain, in a news release.
In the new study, 104 obese or overweight men and women ate a low-calorie diet for eight weeks and were followed up with six months later. Their body weight, ghrelin, leptin, and insulin levels were measured before, during, and after the diet.
Ghrelin is the "go" hormone that tells you when to eat, and leptin is the "stop" hormone that tells you when to stop eating.
On average, study participants dropped about 5% of their body weight while adhering to the low-calorie diet. Six months later, 55 people maintained their weight loss, while 49 regained 10% or more of the weight they had lost. Those individuals with higher leptin and lower ghrelin levels before dieting were more prone to regain weight, the study showed.
While this may seem counter-intuitive based on the actions of these hormones, the researchers suggest that it may be a matter of some people being resistant to the effects of these hormones.
Their brains may not be getting the fullness or satiety messages that these hormones are delivering. You may have a lot of leptin, but your brain is resistant to its effects; much like people with type 2 diabetes become resistant to the effects of the hormone insulin.
Going forward, "these hormone levels could be proposed as biomarkers for predicting obesity-treatment outcomes," the researchers conclude. "Our findings may provide endocrinology and nutrition professionals a tool to identify individuals in need of specialized weight-loss programs that first target appetite hormone levels before beginning conventional dietary treatment."
Louis Aronne, MD, founder and director of the Comprehensive Weight Control Program at New York-Presbyterian Hospital/Weill Cornell Medical Center in New York, agrees. "There is something physical going on in people who regain weight," he says.
"Resistance to these hormones is a risk factor for weight regain," he says. Aronne dubs this condition "fullness resistance" and says that your brain is resistant to signals that come from your stomach and intestines telling you that you are full and to stop eating.