When it comes to losing weight and becoming a healthier person, the struggle for millions of Americans is keeping weight off once it is lost. Little is more threatening to an individual’s motivation or health than the return of poundage one worked so hard to lose. In a new study, scientists have begun looking at this struggle by examining individuals who have lost massive amounts of weight in one of the nation’s most famous weight loss programs. The study, featured in the Houston Chronicle on May 3, focuses on several contestants of the reality T.V. show “The Biggest Loser,” where overweight contestants go through rigorous dieting and exercise in order to lose weight. What the study found is that many of the contestants on that show, some of whom lost hundreds of pounds, saw the excess weight return after the show’s conclusion. On many occasions, former contestants actually ended up heavier than when they first went on the show. Danny Cahill won season eight of “The Biggest Loser” when he slimmed down to 191 pounds, a shadow of the 430-pound man he was when he first came on the show. Today, however, Cahill is back up to 295 pounds, and he has to work hard to keep from gaining any more weight. Kevin Hall, the leader of the study and a researcher at the National Institute of Diabetes and Digestive and Kidney Diseases, says that Danny Cahill’s problem, and the problem of so many Americans, can be attributed to a metabolism that works against the body. Dr. Hall’s study shows that when the contestants rapidly lost weight, their metabolisms slowed just as rapidly. Since metabolism determines how many calories a body burns, a slow one can lead to devastating fat buildup. “It is frightening and amazing,” Hall said of the findings. The reality show’s doctor, Robert Huizenga, says that this study highlights the importance of expert assistance and coaching after massive weight loss. Otherwise, it is incredibly difficult to work against the body’s metabolism and keep weight at bay. Doctor’s hope that the study’s findings make it possible for further research that will combat obesity and weight gain, as well as enable smarter approaches to weight loss. The full study is set to be published May 9.