The human costs of hunger resulting from poor diets are stark and impossible to ignore.

In SOFI 2004 FAO estimates that undernourishment and deficiencies in essential vitamins and minerals take the lives of more than 5 million children every year and cost households in the developing world more than 220 million years of productive life. This occurs because lives are cut short or impaired by disabilities related to malnutrition, and cost developing countries billions of dollars in lost productivity and national income.

A vicious cycle of deprivation

Every year, more than 20 million low birthweight (LBW) babies are born in the developing world. In some places -- India and Bangladesh are examples -- as many as 30% of all children are born underweight.

From the moment of birth, the scales are tipped against them. LBW babies face increased risk of dying in infancy, of stunted physical and cognitive growth during childhood, of reduced working capacity and earnings as adults and, if female, of eventually giving birth to LBW babies themselves.

Scars that last a lifetime

Unsurprisingly, then, almost one third of all children in developing countries are stunted, with heights that fall well below the normal range for their age -- a signal of chronic undernutrition. Stunting, like low birthweight, has been linked to increased illness and death, to reduced cognitive ability and school attendance in childhood and, in adults, to lower productivity and lifetime earnings.

An "invisible" handicap

Undernourishment and stunting frequently overlap with the vitamin and mineral deficiencies that affect nearly 2 billion people worldwide. Even when mild, these deficiencies significantly increase the risk of severe illness and death. They can also cause irreversible cognitive deficits in children and productivity losses for adults.

For example iron deficiency, which afflicts an estimated 1.7 billion people, has been linked to increased maternal mortality in childbirth, poor motor and cognitive development in children and reduced productivity in adults, says FAO.