The principles of the Flat Belly Diet are simple: Have four 400-calorie meals a day (including one snack you can consume in the morning or afternoon), eat every 4 hours and have MUFA-rich food, e.g., peanut butter, almonds, avocados and even semi-sweet choocolate chips, at every meal. Sticking to the following menu of flat belly diet recipes will help you lose up to 15 pounds this month.