Years of dieting have irreparably damaged your metabolism and as a result, you’ll never be as slim as you’d like. Or at least, that’s what a number of doom-mongers would have you believe. In 1984, Geoffrey Cannon published his bestselling book Dieting makes you fat. It sold so well that he re-wrote it and in 2009 released an updated version. Mr Cannon’s claim has become something of an internet meme: the more you restrict your food intake, the likelier you are to get fat in the future. If you loose weight by dieting, you’ll put it all back on, and more, when you stop. There are different explanations for why this paradoxical effect might happen. But regardless, a quick look…