There are many types of diet pills which are being elaborated here. Firstly, weight-loosing diet pills which forbids some specific types of food or food itself in general. It is not very necessary that if by using this technique some one has lost weight and this will equally be beneficial for all. It does not happen because of difference in function of metabolism. Secondly many use weight-gaining diet pills as happens in case of athletes, wrestlers and boxers. They want to put on more weight to have an overwhelming effect on field as well as on their opponent. Thirdly, people who are underweight they again use weight-gaining diet pills to restore normal level of body fats.