Your metabolism increases during sleep, causing you to burn more calories than during the day. When fat takes control of a person's body, however, breathing becomes shallower and the body burns less calories. Due to this one factor alone, we gained weight progressively over several days.If you wish to reduce weight, the majority of medical experts believe that you must monitor your diet. This is because 80% of what you do to maintain your weight has to do with what you eat and 20% with how much you exercise.