If you gain weight, you are probably gaining fat.  If you then lose the weight, you may not be losing the fat.  Therefore, you may weigh less, but be fatter. When you gain weight and fat and then lose the weight, fat cells shrink but don't go away. Try to avoid putting on weight that is a result of increased calorie intake, even for only a short period of time. The reason being that the extra fat cells you add will stay with you and signal your brain that you are hungry.

Fat cells appear most often as upper-body subcutaneous fat ( belly fat) , which is the fat just under the skin.  Fat also can be stored as visceral fat, which is also called deep belly fat or internal fat. Then there is lower body fat which is usually found in the hips, inner thigh and buttock areas. None of these types of body fat are good for you to be carrying around. Excess internal fat will put tremendous pressure on your stomach, pancreas, intestines and other organs. Your organs and glands are responsible for producing hormones. The added pressure from belly fat causes hormonal imbalances and deficiencies found in diabetes and many other health conditions.

When people slim down through diet and exercise, rather than just calorie reduction alone, fat around the organs will disappear twice as fast in comparison to other body fat. Proper nutrition and as little as three days a week of high intensity exercise for 30 minutes per session, can reduce your belly fat and reduce your risk of diabetes significantly. I think that the size of your waist is far more important than what you weigh. Weight does not distinguish between muscle and fat.  Check the Body Mass Index Charts. Body Mass Index (BMI) is a measure of body fat based on height and weight that applies to adult men and women.  Check the U S Department of Health and Human Services web site for more information on BMI and to calculate where you stand versus where you should be on body mass.