We knew things were not looking good between Jennifer Lopez and Casper Smart, and last week the world discovered they are, in fact, over. But, though rumors have flown that the breakup had something to do with Smart's interest in transsexual models, sources tell Radar the truth is a little more mundane. J.Lo is simply "obsessed with her body," a source explains, and has become a "fitness robot" who reportedly sticks to a regimen of 90-minute workouts. She and Smart "had nothing else to talk about except diet and exercise stuff," the source says. "She has become a health and fitness bore. ... It's 'this cleanse,' 'that workout routine,'" all the time. (Click to read about 7 unusual celebrity workouts.)