You must first realize how much food you are eating. Once you have a good idea of how much you normally eat, begin to cut down on that amount, but only by a little bit. Gradually increase the amount of food that you are cutting down. Once you are accustomed to eating a smaller amount, try to begin eating a little healthier. While you are getting healthy, it is important to exercise as well. Always check the ingredients, calories, fat, carbohydrates, and vitamins of the food you buy.