In medicine, wasting, also known as wasting syndrome, refers to the process by which a debilitating disease causes muscle and fat tissue to "waste" away. Wasting is sometimes referred to as "acute malnutrition" because it is believed that episodes of wasting have a short duration, in contrast to stunting, which is regarded as chronic malnutrition. According to the latest UN estimates, an estimated 52 million children under 5 years of age, or 8%, were wasted in 2011. The vast majority, about 70%, of the world's wasted children live in Asia, most in South-Central Asia.United Nations Children’s Fund, World Health Organization, The World Bank. UNICEFWHO- World Bank Joint Child Malnutrition Estimates. (UNICEF, New York; WHO, Geneva; The World Bank, Washington, DC; 2012)
CausesWasting can be caused by an extremely low energy intake (e.g., caused by famine), nutrient losses due to infection, or a combination of low intake and high loss. Infections and conditions associated with wasting include tuberculosis, chronic diarrhea, AIDS, and superior mesenteric artery syndrome. The mechanism may involve cachectin – also called tumor necrosis factor, a macrophage-secreted cytokine. Caretakers and health providers can sometimes contribute to wasting if the patient is placed on an improper diet. Voluntary weight loss and eating disorders are excluded as causes of wasting.
- Children: Weight-for-height (WFH). In infants under 24 months, recumbent (supine) length is used. WFH as % of median reference value is calculated this way:
- * Body Mass Index (BMI) is the quotient between weight and height squared (kg/m2). An individual with a BMI < 18.5 is regarded as a case of wasting.
- *Percent of body weight lost (At Tufts, an unintentional loss of 6% or more in 6 months is regarded as wasting)