AT THE depths of the Great Depression, George Orwell wrote of the English working classes: “The basis of their diet is white bread and margarine, corned beef, sugared tea and potato—an appalling diet. Would it not be better if they spent more money on wholesome things like oranges and wholemeal bread?…Yes it would, but the point is, no human being would ever do such a thing.…A millionaire may enjoy breakfasting off orange juice and Ryvita biscuits; an unemployed man does not…When you are underfed, harassed, bored, and miserable, you don't want to eat dull wholesome food. You want to eat something a little bit tasty.”

Orwell was describing something that has become one of the world's neglected scourges: the bad diet of the poor. When people think of malnutrition, they usually picture its most acute form—listless infants with bloated bellies, the little victims of famine. But there is a chronic manifestation of hunger, too, milder but more widespread. It affects those with enough calories to eat but too few micronutrients (vitamins, minerals and so on). They suffer the diseases of poor nutrition.

These diseases are stunningly widespread. Over half of women in India and two-fifths of those in Indonesia are anaemic—deficient in iron. Lack of vitamin A causes membranes around the organs to shrivel, leaving them vulnerable. The first to go are the eyes: half a million children become blind each year. Then, the other organs: half of those children will die within 12 months. In Malawi a third of the population do not have enough calories; two-thirds lack vitamin A.

Such deficiencies do long-term damage to societies as well as to individuals. Compared with their better-fed peers, nutrition-deficient children have more diseases and lower educational standards (perhaps because they cannot concentrate in class). Nutrition-deficient adults earn less and are more likely to die early (see article). Famines lay waste to countries; bad diets cripple them silently.

Governments often try to deal with the problems of nutrition in the same breath as the problems of starvation: by dishing out cheap food. India gives subsidised food to over 400m poor people. Egypt spends over $2 billion a year on cheap bread. These policies do almost nothing to get micronutrients to those who lack them.

What is needed are little interventions: adding iodine to salt here, doling out vitamin A supplements there. Even relatively small doses work. Yet they also raise one of the great puzzles of development. These are, by some measures, the best investments you could make. When the Copenhagen Business School asked some Nobel-winning economists the best way to spend money to help the world, nutritional projects topped the poll. Vitamin A supplements cost just a dollar or two. Their benefits—preservation from fatal diseases, higher lifetime earnings—so massively outweigh the tiny costs that poor people ought to snap them up. Yet they don't. Orwell put his finger on why. The poor want something tasty. They may not believe nutritional experts who promote special diets (rich Westerners have been known not to stick to diets, too). Or food itself may not be their priority. As Orwell said, “There is always some cheaply pleasant thing to tempt you.”

Good food by stealth

The implication is that there should be a rethink of poor countries' food policies. Top-down efforts fail. But governments, companies and international institutions can do good by stealth. Firms like Nestlé and Kraft are busy stuffing packaged foods with extra nutrients. People buy them because they like the taste. “Biofortified” foods (crops with extra vitamins bred into them) work, too. Public money should be concentrated not on supplying cheap food but on providing for those who do not control what they eat: babies and children. The most important period in anyone's nutritional life is the first 1,000 days. Improving infant diets does a lifetime of good. But this depends on education and policy “nudges”, not cheap rice.