Why the market for mud cakes is booming in Haiti

They're mud cakes, made from clay, salt, oil and water. Eat one, and you'll keep hunger at bay for a few hours.

In Haiti, the market for mud cakes is booming. With the price of food soaring, but with wages static or falling, the poor are forced into desperation. Haiti finds itself at the whip end of a food crisis that stretches around the world.

Sign of the times: A woman dries mud cakes in the sun in Port-au-Prince, Haiti

Globally, food prices rose 55 per cent from June 2007 to February 2008. In March alone, the price of rice went up 87 per cent - and rice accounts for one fifth of all calories eaten on Earth. The prices of all staples have soared and are set to rise for the next decade.

There's a fistful of reasons why prices are so high.

First, the price of oil is connected to our food. It's not just through the energy used to bring food to our door. On the average American farm, the greatest use of energy is on fertilisers, which require tremendous amounts of fossil fuels to manufacture. More expensive oil means pricier fertiliser which, in turn, means dearer food.

Another reason prices are high is because of the boom in 'biofuels'. In 2006, the American government spent $12billion (£6billion) to turn maize into ethanol, which was mixed with petrol and sold as 'flexible fuel'.

This made farmers think they'd be better off growing maize rather than wheat. So the supply of wheat was cut and the price rose. Speculators saw the boom in the maize market and bet the price of white maize, grown in Mexico, would go up. The price soared. With it, so did the price of the Mexican staple, tortillas. That's why there were 'tortilla riots' in Mexico City last year.

While President George W. Bush puts the contribution of biofuels to the increasing food prices at no more than four per cent, and the World Bank claims it could be as high as 75 per cent, most analysts put the figure at about 25 per cent.

So, a quarter of the world food-price crisis is because we think it's a better idea to burn food than eat it.

A girl walks through a corn field in Deschapelles, Haiti, where poverty puts food out of the reach of many

The lunacy of biofuels has been made worse by unusual weather, such as the decade-long Australian drought, the recent flooding in the United States, and wheat rust in Asia.

And, on top of this, price speculation and collusion within the food industry have added another layer to the cost of food. In Britain, Spain and South Africa, price-fixing enquiries are under way to see whether supermarkets have used the crisis to overcharge consumers.

Perhaps, we might think, there just isn't enough food. But the world's food production has been growing faster than the population every year since the Sixties.

Haiti, again, points to the real problem. If you go to the cruise port of Labadee, you'll find more food than you can shake a stick at. But people are too poor to afford it.

In 2006, before the food crisis hit, there were 850million people who were hungry at some point during the year. Of those, seven out of ten were women. Today, the number of hungry people is closer to a billion.

Girls and pregnant women are particularly at risk of malnourishment. Yet while they own less than 15 per cent of the land, women produce three quarters of all food eaten in developing countries.

It is one of the bitterest ironies that the world's worst-paid people are those who grow our food.

Even in America, there are reports of middle-class women skipping meals so their children can eat. The food crisis is hitting everywhere.

But there are things we can do to beat it. When it comes to food aid, the United States has one of the most destructive policies: the food has to come from American farms and be delivered by American ships.

While free food might seem a blessing, imagine if you're a struggling farmer in a hunger-affected region. You're trying to make a living selling your crop and then free American food floods in. You're wiped out. The answer is for donor countries to buy food as close as possible to where it's needed.

We also need to stop being dependent on fossil fuels to produce food. From Nepal to Nicaragua, there are some spectacular examples of agro-ecological farming, which doesn't use artificial fertilisers or pesticides. This method, which embraces holistic methods to grow food, shows sixfold increases in output compared with conventional agriculture.

Ultimately, to solve the main problem at the heart of the food crisis we need to eliminate poverty. The best place to start is to invest in girls' education. This would tackle the world's greatest inequality and it is also the most effective way of reducing population growth.

But certain hunger-beating policies simply don't fit the current fads in international development economics. Perhaps that's the greatest tragedy here. It's not a lack of food that is causing this crisis - it's a lack of political will.

• Stuffed And Starved, by Raj Patel, is published by Portobello, price £8.99. To order your copy at £8.99 with free p&p call The Review Bookstore on 0845 155 0713.