Identify your unhealthy nutritional habits and get rid of them one at a time. Replace your bad habits with healthier alternatives. Then, give yourself enough time to get used to your new habits. Unhealthy habits include overeating, eating throughout the day instead of having three meals a day, snacking and eating foods that contain unhealthy ingredients. Check the labels of the foods you buy to find out more about the ingredients and calculate how many calories you need in a day to make sure you are not overeating. Meet with a nutritionist to talk about your diet if you have a hard time identifying unhealthy habits.