What is 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.
Unintentional weight loss may be a result of loss of fat, muscle atrophy, fluid loss or a combination of these.[1][2] 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[1] or 5% in the last month.[3]Another criterion used for assessing weight that is too low is the body mass index or BMI.[4] However less weight loss can be a cause for serious concern in a frail elderly person, for example.[5]
Unintentional weight loss can occur because of a diet lacking in adequate nutrition for a person's energy needs (generally calledmalnutrition). But it can also occur because of disease processes, changes in metabolism, hormonal changes, as an adverse effect of medication or other treatment, disease- or treatment-related dietary changes, or reduced appetite associated with a disease or treatment.[1][2][6][7][8] Serious weight loss may reduce quality of life, impair treatment effectiveness or recovery, worsen disease processes and be a risk factor for earlier mortality.[1][5] Malnutrition can affect every function of the human body, from the cells to the most complex functions, including:[4]
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.[4]
Unintentional weight loss can be the characteristic leading to diagnosis of diseases such as cancer[1] and type 1 diabetes.[9]
Continuing weight loss may deteriorate into wasting, a vaguely defined condition called cachexia.[5] Cachexia differs from starvationbecause it involves a systemic inflammatory response.[5] It is associated with poorer outcomes.[1][5][6]
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.[4] 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.[4] A high proportion (10-60%) of hospital patients are also at risk, along with a similar proportion in care homes.[4]
Unintentional weight loss may be a result of loss of fat, muscle atrophy, fluid loss or a combination of these.[1][2] 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[1] or 5% in the last month.[3]Another criterion used for assessing weight that is too low is the body mass index or BMI.[4] However less weight loss can be a cause for serious concern in a frail elderly person, for example.[5]
Unintentional weight loss can occur because of a diet lacking in adequate nutrition for a person's energy needs (generally calledmalnutrition). But it can also occur because of disease processes, changes in metabolism, hormonal changes, as an adverse effect of medication or other treatment, disease- or treatment-related dietary changes, or reduced appetite associated with a disease or treatment.[1][2][6][7][8] Serious weight loss may reduce quality of life, impair treatment effectiveness or recovery, worsen disease processes and be a risk factor for earlier mortality.[1][5] Malnutrition can affect every function of the human body, from the cells to the most complex functions, including:[4]
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.[4]
Unintentional weight loss can be the characteristic leading to diagnosis of diseases such as cancer[1] and type 1 diabetes.[9]
Continuing weight loss may deteriorate into wasting, a vaguely defined condition called cachexia.[5] Cachexia differs from starvationbecause it involves a systemic inflammatory response.[5] It is associated with poorer outcomes.[1][5][6]
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.[4] 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.[4] A high proportion (10-60%) of hospital patients are also at risk, along with a similar proportion in care homes.[4]
