Intentional weight loss occurs as a result of dieting and exercise, or through cosmetic surgery. Unintentional weight loss is an involuntary decrease in body weight and can be a manifestation of illness. In other words, you did not try to loss the weight by dieting or exercising. According to health experts, there are great health benefits to be gained from even a small amount of weight loss if: You have a significantly high body mass index (BMI) and considered obese. You have weight-related health problems or a family history of such problems that causes you to become overweight based on your BMI. Your waist measures more than 40 inches (M) and more than 35 inches (F).

There are many causes of unintentional weight loss. Some are AIDS, cancer, depression, diarrhea that is chronic (lasts a long time), including amphetamines, chemotherapeutic agents, laxative abuse, and thyroid medications, drug abuse, eating disorders, including anorexia nervosa and bulimia, hyperthyroidism, infection, loss of appetite, malnutrition, manipulative behavior (in children), painful mouth sores, mouth braces, or a loss of teeth that prevent you from eating normally, smoking, diabetes, parkinson's disease, stroke, and tuberculosis.

Weight loss is also a symptom of other diseases and conditions of the body. The loss of weight and lack of nutrition associated with a chronic illness is referred to as cachexia. Decreased body fluid, muscle mass, or fat also results in weight loss. A decrease in body fluid can come from taking certain medications, fluid loss, lack of fluid intake, or illnesses such as diabetes. Weight loss is also normal after pregnancy. The treatment for weight loss is treating the underlying causative disease or condition of the body. A weight loss of 5 to 15 percent of body weight may improve your health and quality of life, and prevent these health problems.

For a person who weighs 200 pounds, that means losing 10 to 30 pounds. Obesity is a chronic disease that affects many people and may require long-term treatment in order to promote and sustain weight loss. As in other chronic conditions, such as diabetes or high blood pressure, long-term use of prescription medications may be appropriate for some people. Even if you do not need to lose weight, you still should follow healthy eating and physical activity habits to help prevent weight gain and stay healthy as you age.