Initially, people skimp on non-staple foods, cutting the quality and diversity of their intake; in the next stage, the quantity and safety of diets suffer. That in turn damages their health. Currently, around 50m, or 40 per cent, of pregnant women in developing countries are anaemic. Anaemia in expectant mothers, which causes low birth weight and unhealthier babies, is likely to rise by a further 1.2m in Asia and 700,000 in Africa.

To make matters worse, this is happening at a time when the global slump is causing job losses or wage squeezes everywhere — worldwide unemployment rose to 6 per cent in 2008 — so in some poor countries, it now takes an extra ten hours a week or more to feed a family of five.

The resulting burden falls heavily on women. As the report says starkly: "Women are usually the last to benefit from increasing income [but] they are usually the first to make sacrifices when the financial situation deteriorates."

© The Economist Newspaper Limited 2009