weight loss
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.
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 an elderly person's body weight has been lost in six months or 5% in the last month. Another criterion used for assessing weight that is too low is the body mass index (BMI). However, less 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. Serious weight loss may reduce quality of life, impair treatment effectiveness or recovery, worsen disease processes and be a risk factor for earlier mortality. Malnutrition can affect every function of the human body, from the cells to the most complex functions, including:
immune response;
wound healing;
muscle strength (including respiratory muscles);
renal capacity and depletion leading to water and electrolyte disturbances;
thermoregulation; and
menstruation.
In addition, malnutrition can lead to vitamin and other deficiencies and to inactivity, which in turn may pre-dispose to other problems, such as pressure sores.
Unintentional weight loss can be the characteristic leading to diagnosis of diseases such as cancer[1] and type 1 diabetes.
Continuing weight loss may deteriorate into wasting, a vaguely defined condition called cachexia.Cachexia differs from starvation because it involves a systemic inflammatory response. It is associated with poorer outcomes.
In the UK, up to 5% of the general population is underweight, but more than 10% of those with lung or gastrointestinal diseases and who have recently had surgery. According to data in the UK using the Malnutrition Universal Screening Tool ('MUST'), which incorporates unintentional weight loss, more than 10% of the population over the age of 65 is at risk of malnutrition. A high proportion (10-60%) of hospital patients are also at risk, along with a similar proportion in care homes.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.