Wasting is a symptom of acute under-nutrition and is usually a combined consequence of insufficient food intake and a high incidence of infectious diseases, especially diarrhoea. In many developing countries, wasting most severely affects children during the second year of life, when they are no longer breast-fed. The missing benefits of breast milk are often not compensated by nutritious weaning foods. And in the absence of breast milk, children lose their protection against infection at just the time when they are becoming increasingly mobile and coming into direct and frequent contact with an often unhealthy environment.
Stunting, on the other hand, is a consequence of chronic under-nutrition arising from insufficient food intake and exposure to infections over a long period. Given the cumulative effect of these conditions, the longer they prevail the more likely a child is to be stunted. Stunting is a more widespread condition than wasting, and as many children seem to adapt to it and to function at or near normal levels, there is some debate about how severe stunting really is. In the long term, however, this condition has a number of serious consequences. For example, women who themselves were stunted during childhood are more likely to develop complications when they have their own babies and to give birth to low-birth-weight children.
Wasting and stunting represent two quite different biological processes. "Wasted" describes a child who is abnormally thin; "stunted" describes one who is abnormally short. Wasting peaks in the second year, when children are finally weaned from the breast and are most exposed to diarrhoeal disease. Stunting is a different and controversial matter, particularly because it is accompanied by mental retardation. If being short is being malnourished, the 50% of children in countries such as Bangladesh and Nepal should be considered undernourished. There is evidence to suggest that whereas wasting results from an inadequate amount of food, stunting results from an inadequate quality of food, in respect perhaps of protein, or of minerals such as calcium or zinc. Moreover it has been shown that both physical and mental stunting are reversible.
For a long time it was the custom to assess the degree of
A stunted child is adapted. It needs less food and therefore is more likely to survive when food is short.