weight loss weight loss weight loss, in the context of medicine, health, or physical fitness, refers to a reduction of the total body mass, by a mean loss of fluid, body fat (adipose tissue), or lean mass (namely bone mineral deposits, muscle, tendon, and other connective tissue). weight loss can either occur unintentionally because of malnourishment or an underlying disease, or from a conscious effort to improve an actual or perceived overweight or obese state. "unexplained" weight loss that is not caused by reduction in calorific intake or exercise is called cachexia and may be a symptom of a serious medical condition. weight loss part of a series onhuman body weight general concepts obesity (epidemiology) overweight underweight body shape weight gain weight loss gestational weight gain diet (nutrition) weight management overnutrition childhood obesity (epidemiology) medical concepts adipose tissue classification of obesity genetics of obesity metabolic syndrome (epidemiology of metabolic syndrome) metabolically healthy obesity obesity paradox set point theory measurements body adiposity index body mass index body fat percentage body shape index corpulence index lean body mass relative fat mass waist–hip ratio waist-to-height ratio related conditions diabetes (type 1) eating disorder (anorexia • bulimia • binge eating disorder) food addiction hyperthyroidism malnutrition red-s starvation (starvation response) pcos obesity-associated morbidity arteriosclerosis atherosclerosis fatty liver disease gerd gynecomastia heart disease hypertension obesity and cancer osteoarthritis prediabetes sleep apnea type 2 diabetes management of obesity anti-obesity medication bariatrics bariatric surgery dieting (list of diets) caloric deficit exercise (outline) liposuction obesity medicine weight loss camp weight loss coaching yo-yo effect social aspects comfort food fast food (criticism) fat acceptance movement fat fetishism health at every size hunger obesity and the environment obesity and sexuality sedentary lifestyle social determinants of obesity social stigma of obesity weight cutting weight class intentional intentional weight loss is the loss of total body mass as a result of efforts to improve fitness and health, or to change appearance through slimming. weight loss is the main treatment for obesity, and there is substantial evidence this can prevent progression from prediabetes to type 2 diabetes with a 7-10% weight loss and manage cardiometabolic health for diabetic people with a 5-15% weight loss. weight loss in individuals who are overweight or obese can reduce health risks, increase fitness, and may delay the onset of diabetes. it could reduce pain and increase movement in people with osteoarthritis of the knee. weight loss can lead to a reduction in hypertension (high blood pressure), however whether this reduces hypertension-related harm is unclear. weight loss is achieved by adopting a lifestyle in which fewer calories are consumed than are expended. depression, stress or boredom may contribute to weight increase, and in these cases, individuals are advised to seek medical help. a 2010 study found that dieters who got a full night's sleep lost more than twice as much fat as sleep-deprived dieters. though hypothesized that supplementation of vitamin d may help, studies do not support this. the majority of dieters regain weight over the long term. according to the uk national health service and the dietary guidelines for americans, those who achieve and manage a healthy weight do so most successfully by being careful to consume just enough calories to meet their needs, and being physically active. for weight loss to be permanent, changes in diet and lifestyle must be permanent as well. there is evidence that counseling or exercise alone do not result in weight loss, whereas dieting alone results in meaningful long-term weight loss, and a combination of dieting and exercise provides the best results. meal replacements, orlistat, a very-low-calorie diet, and primary care intensive medical interventions can also support meaningful weight loss. techniques