Why it works

The fortified peanut butter that the children from Niger are receiving is rich in vital vitamins, minerals and calories. Peanuts contain mono-unsaturated fats, which are easy to digest. They are also very high in calories, which means that a child will get a lot of energy from just small amounts (important because their stomachs have shrunk). They are rich in zinc and protein — both good for the immune system. Protein is also needed for muscle development.

Peanuts are a good source of vitamin E, a powerful antioxidant that helps to convert food into energy.

All this is why the NGO with which I work in India gives street children peanut butter — it helps to counter malnourishment. Peanuts are a wonder food, really — the problem that we in the West have is that there is such a high incidence of peanut allergy, perhaps because we are too clean. Another theory is that we introduce nuts relatively late compared with other cultures.

Plumpy'nut was created by André Briend, who spent years working in humanitarian crises. He realised that a ready-to-eat supplement that needs no cooking or added water, and is cheap to produce, could help to save millions of lives in remote and under-developed areas. Plumpy'nut is now produced in Normandy by a company that specialises in food relief, in partnership with Unicef, the United Nation's children's organisation.

The UN says that 150,000 children under 5 are severely malnourished in Niger and a further 650,000 are moderately malnourished. This translates into ankles and wrists barely wider than a man's thumb.

The success of plumpy'nut, which is normally given for four weeks at a cost of £12, in treating that problem is raising some awkward questions, particularly for the governments whose children stand to benefit.

"It is cheap to produce and deliver, so why is it not being manufactured locally and given to children all over Africa?" asks Adrian Hartley, a white Kenyan author and commentator on Africa. "These governments always have money to buy their Mercedes cars and guns — so why not some plumpy'nut?"

A peanut butter paste fortified with milk and vitamins is helping to save the lives of thousands of malnourished children in crisis-torn Niger

Hilinki Tchadoua's black eyes sparkle with life. Huge saucer-like objects, they stare out of a tiny face as if she is barely able to believe her good fortune as she sucks on fingers from a wizened hand.

At ten months, she is too weak and frail to do anything other than move her arm back and forth from the red plastic cup lying at her feet as she slowly brings a brownish porridge-like substance to her mouth.

"This is about as bad as you get," says the nurse working at this emergency feeding centre for malnourished children in southern Niger. "But already the change is amazing. It is as if you can see her growing before you."

Ousseina, her teenage mother, nods approvingly. "Before I came here I could not give her enough to eat. Now she is growing strong again."

In Niger, where the United Nations says 150,000 children could die, Hilinki is lucky. She was so badly malnourished that she was admitted to this clinic, run by the medical aid organisation Médecins sans Frontières (MSF), for an intensive five-day feeding programme, and she is now feasting on a beige paste known as plumpy'nut.

Plumpy'nut — a fortified peanut butter stuffed with milk and vitamins — is just the sort of food that overweight Western children are advised to avoid. But for malnourished children it has an amazing effect, making it the undisputed hero of the current crisis in Niger, where 3.6 million people — 800,000 of them children — face severe food shortages.

Within two days, Hilinki's weight has climbed from 4.6kg to 5kg (10lb to 11lb). She will stay at the clinic for a further three days and receive six meals a day. Nearly all of it will be plumpy'nut — a merging of the words peanut and plump — which can add as much as 1kg (2.2lb) a week to a hungry child's weight.

"It is the only thing in this crisis that has acted quickly," says an MSF nutritional assistant in a reference to the slow response of the international community to appeal after appeal ahead of the current tragedy in Niger.

Near by, Absu, a four-year-old girl whose curly black hair is shot with streaks of blonde — one of the telltale signs of severe malnutrition — sits on a plastic sheet at the feet of her grandmother and also hungrily devours a plate of the apparently magic paste. "She became sick some time ago — since last year we have not had enough to eat," says Abu, her grandmother.

"I have struggled every day to find her food, but nothing works like the stuff they have here." Absu's mother died two years ago giving birth to another child.

Plumpy'nut, devised by a French scientist less than two years ago, is simple to deliver and to administer and has changed the nature of food-relief efforts. It comes in a small foil package, 2in square, and is given to children by their mothers. Once back to normal weight for their age, children need only one sachet a day to remain healthy.

Previously, malnourished children were given milk and other vitamin-packed substances in hospital, by drip. It took several weeks for them to regain strength, and all the while they occupied precious space in hastily erected emergency centres. Once they are back home, their only hope of survival would be if their mothers, often weak and hungry themselves, could supplement their breast-feeding with special milk formulas. Those are costly and in areas of poor water supply prone to spreading other diseases, such as diarrhoea — which can kill weak children. Aid workers are unanimous in their approval of the product.

"Normally, in a crisis like this, several children relapse once discharged, but here in Niger the number of returns is very low. This means we are getting something right," says Johanne Sekkenes, the head of MSF in Niger.

Plumpy'nut was first used last year during the crisis in Darfur in western Sudan, but it is in Niger that it has come into its own. The crisis in the vast desert country in West Africa is not a traditional famine. There is plenty of food in the markets, but prices have rocketed because of a poor harvest after years of drought and, last year, the worst locust invasion for 40 years.

"This is a nutritional crisis, " Johanne Sekkenes explains. "Children are suffering from the cumulative effects of poor diets, a lack of health services, and diseases, such as diarrhoea. That is why they are in a far worse state than the adults."

Aid agencies have given warning that if food-relief efforts now under way are not sustained and there is another poor harvest then a catastrophic famine will follow.