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. An estimated 45 million children under 5 years of age (or 6.7%) were wasted in 2021.[1]: 4 Prevalence is highest in Southern Asia, followed by Oceania (excluding Australia and New Zealand) and South-eastern Asia.[1]: 14