Weight loss is a decrease in body weight due to a decline in fat and/or muscle. It may be a desirable outcome, for instance, if someone is obese, overweight or is struggling with unwanted weight gain. However, it may also be an undesirable side effect of certain medications, medical conditions or eating disorders.
Unexplained weight loss may be a sign of an underlying medical condition, such as cancer, gastroenteritis, HIV, depression, bowel diseases, or hyperthyroidism. Certain procedures and treatments, for example, chemotherapy, may also cause weight loss.
Lifestyle and dietary changes, such as regular exercise and a calorie-restricted diet, are normally recommended for people trying to lose weight. In some cases, physicians may prescribe medication to promote weight loss.
Drug classes used to assist with weight loss include other antiobesity products, centrally-acting antiobesity products, psychostimulants, amphetamines, and peripherally-acting antiobesity products.