Weight loss, in the context of medicine, health or physical fitness, is a reduction of the total body mass, due to a mean loss of fluid, body fat or adipose tissue and/or lean mass, namely bone mineral deposits, muscle, tendon and other connective tissue. It can occur unintentionally due to an underlying disease or can arise from a conscious effort to improve an actual or perceived overweight or obese state. Intentional weight loss refers to the loss of total body mass in an effort to improve fitness and health, and/or 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, osteoarthritis and certain types of cancer. While being overweight had been thought to be linked to stroke there is no strong evidence to support that link. Attention to diet in particular can be 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 thermodynamic flux: 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. It is not uncommon for some people who are currently at their ideal body weight to seek additional weight loss in order to improve athletic performance, and/or meet required weight classification for participation in a sport. However, others may be driven by achieving a more attractive body image. Notably, being underweight is associated with health risks such as difficulty fighting off infection, osteoporosis, decreased muscle strength, trouble regulating body temperature and even increased risk of death. There are many diet plans and recipes that can be helpful for weight loss. While some are classified as unhealthy and potentially harmful to one's general health, others are recommended by specialists. Diet plans are generally designed according to the recommended caloric intake but it is important to note that the most successful diets are those that simultaneously promote physical activity. There are many dietary programs that claim to be efficient in helping overweight individuals to lose weight with no effort. However, the long-term efficacy of these plans is questionable.