    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. "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.  intentional weight loss is commonly referred to as slimming. ==unintentional== ===characteristics=== unintentional weight loss may be a result of loss of fat, muscle atrophy, fluid loss or a combination of these. it is generally regarded as a medical problem when at least 10% of a person's body weight has been lost in six months or 5% in the last month.page 67 in: the role of nutrition in maintaining health in the nation's elderly: evaluating coverage of nutrition services for the medicare population. author: institute of medicine (u.s.). committee on nutrition services for medicare beneficiaries. isbn 0-309-06846-0, isbn 978-0-309-06846-8 another criterion used for assessing weight that is too low is the body mass index (bmi). however, even lesser amounts of weight loss can be a cause for serious concern in a frail elderly person. unintentional weight loss can occur because of an inadequately nutritious diet relative to a person's energy needs (generally called malnutrition). disease processes, changes in metabolism, hormonal changes, medications or other treatments, disease- or treatment-related dietary changes, or reduced appetite associated with a disease or treatment can also cause unintentional weight loss.{{cite journal|last=itoh|first=m|author2=tsuji, t |aut
Dietetics Nutrition Obesity Symptoms_and_signs:_General Weight_loss