Seven years ago, when he became too fat to stand up, Jesús Salvador Torres lay down on the cement floor of his parents’ humble living room in western Mexico. He has been there ever since – sleeping, bathing, defecating and, above all, eating.

“He loved his food,” says Salvador Torres, Jesús’ father. “He would always ask for a second helping.” Today, Jesús has the arteries of a 65-year-old and weighs 200 pounds. The biggest worry is that he is only nine. Jesús is an example – albeit an extreme one – of a public health problem that is sweeping Mexico. According to statistics published last month by the health ministry, the country now has the fattest population in the world, with 70 per cent of adults either overweight or obese.