For some, the show “The Biggest Loser” was a source of entertainment; for others, it was the source of inspiration. For scientists, it is shaping up to be an incredible experiment in the way our metabolisms help us fight to keep off weight. 13 of the 14 contestants in a recent studied regained weight in the six years after their participation in the hit TV challenge and nearly all of the contestants have slower metabolisms than they did when they began. So what does this mean for the human body?
Scientists first looked into the case of Danny Cahill, the winner of The Biggest Loser in 2009, to answer that question. At the end of the competition, Cahill weighed 191 pounds, down from 430. After winning the show, he became a pillar of transformation—flying to public appearances and telling stories of his success. But in the years since that initial buzz, more than 100 pounds have crept back, despite his best efforts to keep them off.
Danny’s story is a common thread among former contestants—a phenomenon that has led to remarkable discoveries about the physiology of obesity that could explain why keeping the weight off is so difficult.
The study of Season 8 contestants was initiated by Kevin Hall, a scientist at a federal research center and an expert on metabolism who frequently tuned into the show. The project was designed to measure what happened to people over six years after they had lost large amounts of weight with intensive dieting and strict exercise. Hall concludes it is both “frightening and amazing” how hard the body works to fight back against weight loss.
The key lies with resting metabolism, which determines how many calories someone burns when they are at rest. When the show began, the contestants had normal metabolisms for their size—burning a normal number of calories for their abnormally large weight. By the time the winner was selected, their metabolisms had slowed radically, their bodies struggling to maintain their new figures.
Though researchers have long known that almost anyone who deliberately loses weight will have a slower metabolism when the diet ends, they were shocked to discover the second factor: even as six years passed and the numbers on the scale climbed, the contestants’ metabolisms did not recover. In fact, they became even slower—their bodies appearing to intensify their efforts to pull the contestants back to their original weight. For Cahill, that means eating 800 fewer calories a day than a typical man his size, or risking anything he consumes turning directly to fat.
This insight helps us understand why it has been so difficult to make headway against the nation’s obesity problem, which impacts more than a third of American adults. The study’s findings are just one part of a scientific push to answer fundamental questions about this epidemic by helping us understand why being fat makes so many people develop medical conditions. It will also help provide a fresh perspective toward medical care for the obese.
Source: The New York Times