You'll never eat a burger again

Fast-food urban myths - we love them. Like the one about the deep-fried rat served as a burger.

Or the chain that rears beakless chickens so the birds cannot attack each other in their tiny coops. Or the outlets that refer to 'milkshakes' as 'shakes' because lard is used instead of milk.

Fast Food Nation is full of equally gruesome tales, but this time the truth of them has never been challenged. Since its publication in January, the book has been the talk of America - the birthplace of fast food - and will be available in Britain from the end of the month.

Sure, we already know that fast food is bad for us - good only as a quick hunger fix or an instant hangover cure. But Fast Food Nation could make a difference to the way we eat. Forever. As its author, award-winning investigative journalist Eric Schlosser, writes, 'What we eat has changed more in the last forty years than in the previous forty thousand.'

The book investigates the fast-food chain, from the slaughterhouse to the factories where chemical flavours are concocted, to the restaurant floor and beyond. Indeed, some reviewers found certain chapters, such as the one on abattoirs, so nauseating that they could not finish the book.

The facts do require a strong stomach. Think you're cutting down on mad cow risk by only having a burger a month? Sorry, no. A single burger, says Schlosser, can contain meat from dozens - even hundreds - of different cattle. Burgers can also contain traces of faeces, either from filthy hides pulled off the dead cattle or accidentally dribbled from the extracted intestines. Is it really surprising, then, that every day 200,000 Americans get food poisoning, 900 are hospitalised and 14 die?

Want more? Well, according to Schlosser, McDonald's fries derive some of their flavour from animal products. Your average strawberry milkshake flavouring contains more than 50 chemicals. Most fast-food tastes and aromas are manufactured at large chemical plants off the New Jersey Turnpike. Many fast- food workers will not eat anything in their restaurant unless they make it themselves.

'I've been eating fast food all my life and feeding it to my kids, but I had no idea where the food was coming from,' says Schlosser on the phone from San Francisco. 'And I consider myself a reasonably well-educated and well-informed person. Finding out about this food was really my impetus.'

The book started life as an article for Rolling Stone, where it generated more mail than any item the magazine had run in years. 'My original aim was a kitschy, funny look at fast food in America. I never thought I'd be exposing a dark side.'

Schlosser spent two years researching Fast Food Nation. It is heaving with facts, gleaned from hundreds of interviews from farmers to fast-food employees. It is meticulously researched and beautifully written. Schlosser also worked for seven months with a fact checker; the fast-food giants are notoriously litigious and none have directly challenged Schlosser.

Alongside the unpalatable preparation of food, Schlosser focuses on the greed of the big chains. Workers are often sent home during slow periods so the company can avoid paying overtime. Unions are non-existent. Schlosser discovered that during the late Sixties and early Seventies, one giant established a 'flying squad' of managers who were dispatched to any restaurant suspected of union activity. Some employees were even forced to take lie-detector tests.

The findings could spark a timely debate about the fast-food industry. Foot and mouth is in full swing. And the rise in anti-globalisation sentiment means that public consensus is already turning against homogenisation - the same restaurant, the same menu, but in a different city. And then there's the health issue.