Lu Zhihao, world's heaviest 4-year-old

Lu Zhihao, 4, eats a roast chicken wing at a market in Foshan, Guangdong province March 29, 2011.Photograph by: Joe Tan, ReutersLu Zhihao, who is 3 feet 7 inches (1.127cm) tall and weighs 136 lbs (61kg), put on weight dramatically since his appetite grew when he was 3 months old. His worried parents took him to several hospitals, but the reason for his obesity remains unknown, though it is