Children exercise with dumbbells at a military training camp during a weight-loss course in Tianjin, North China, Aug 13, 2011. More than 20 obese children take part in a series of courses to reduce weight during the summer holidays. [Photo/CFP]

A boy takes physical exercise at a military training camp during a weight-loss course in Tianjin, Aug 13, 2011. [Photo/CFP]