Intentional weight loss refers to the loss of total body mass in an effort to improve fitness and health, and to change appearance. Therapeutic weight loss, in individuals who are overweight or obese, can decrease the likelihood of developing diseases such as diabetes, heart disease, high blood pressure, stroke, osteoarthritis, and certain types of cancer.
Attention to diet in particular can be extremely beneficial in reducing the impact of diabetes and other health risks of an overweight or obese individual.
Weight loss occurs when an individual is in a state of negative energy balance: when the body is exerting more energy (i.e. in work and metabolism) than it is consuming (i.e. from food or other nutritional supplements), it will use stored reserves from fat or muscle, gradually leading to weight loss.