After ‘The Biggest Loser,’ Their Bodies Fought to Regain Weight

The Science of Fat Contestants lost hundreds of pounds during Season 8, but gained them back. A study of their struggles helps explain why so many people fail to keep off the weight they lose. Danny Cahill, playing the bass during a church service near Tulsa, Okla., won Season 8 of the NBC show “The Biggest Loser” by dropping 239 pounds.