Fat burners are supplements that help to remove fat and to define the muscle. Fat burners accelerate metabolism, calm the appetite and reduce the production of fats. They transform fat into energy. This type of supplement must be accompanied by physical effort in order to be effective. There are several types of fat burners: thermogenics that use the accumulated fat as fuel and usually have stimulating ingredients; lipotropics, which do not have stimulating substances and also use fats as a source of energy; CLA or conjugated linoleic acid, which reduces fat while increasing muscle mass; diuretics, which reduce the excess liquid in the body; carbohydrate and fat blockers, which keep the body from absorbing fat during digestion.