How Your Appetite Can Sabotage Weight Loss
New research is shedding light on a question that has long confounded dieters and obesity researchers alike: Why do so many people regain weight after they’ve worked so hard to lose it?
The answer, according to a new study, is appetite. People who successfully lose weight get really hungry — more than anyone had ever expected that they might. The body prompts us to eat about 100 calories more than usual for every 2 pounds or so of weight lost, researchers found.
“That’s the very first time that number has been quantified. We never knew how big that number was before the study,” says researcher Kevin Hall, PhD, who studies how the body responds to weight loss at the National Institutes of Health in Bethesda, MD.
It’s this surge in appetite, even more than the drop in metabolism people have after weight loss, that drives weight regain, he says.
The effect of appetite is three times stronger than the slowing metabolism. The two together almost virtually assure that lost pounds will creep back on, Hall says.
Independent experts who reviewed the study, which will be published in the November issue of the journal Obesity and presented on November 2 at the ObesityWeek conference, say it will probably change how doctors treat patients who’ve lost weight.
“This is a landmark study,” says Ken Fujioka, MD, director of the nutrition and metabolic research center at the Scripps Clinic in Del Mar, CA. “It gives us very useful information that will actually help us develop new guidelines,” to prevent weight regain, he says.
“We get patients all the time that hit these plateaus, and we’re trying to figure out, what do we do?” Fujioka says. “It’s real clear to us that you really need to deal with the food intake side, the driven appetite, from this paper.”
Metabolism and Food Intake
By some estimates, 80% of people who successfully lose at least 10% of their body weight will gradually regain it to end up as large or even larger than they were before they went on a diet
Obesity researchers have been working for decades to understand why it is so hard to maintain weight loss. The prevailing theory — proved dramatically in a study of contestants from “The Biggest Loser” reality TV show that Hall published earlier this year — is that the body’s ability to burn calories at rest, or its resting metabolism, slows down, making it easy to regain weight.