Overview: It all depends on calories, you need a certain amount to live, but without exaggerating. The risk of obesity is increasingly frequent, at least in our rich societies. Then it also depends on what foods we eat to obtain the energy we need. So? Let's eat the right amount, avoid junk foods and maybe do some exercise. Easy to say! Otherwise, there are diets. But beware of those fake ones that make you lose weight more than your waistline... your wallet!