This is close to a perfect world: Eating what you love and taking care of your health at the same time. A new study shows that eating some chocolate at least once a week reduces the risk of irregular heartbeat, a common problem that affects one in four people at some time. The amount that needs to be eaten varies between the sexes: women can eat just one ounce, or 30g, of chocolate to have the protective effect, while men need to eat between two and six servings a week. A 30g serving is around a third of the standard 100g chocolate bar.