The trans-fat debate

DIET: In 2004 President Bush ordered the labelling of foods that contain trans-fatty acids

DIET: In 2004 President Bush ordered the labelling of foods that contain trans-fatty acids. These trans-fats were implicated in Kritchevksy's early experiments on rabbits.

When he fed them a semi-purified diet, one including trans-fats, the rabbits developed arteriosclerosis. Kritchevsky maintains that the harm done by trans-fats is minimal.

Recent research has played down their presence in western diets. Opponents of trans-fats point out, however, that because trans-fats are not labelled, it is impossible to say how much of them we consume. Trans-fats are found in many popular foodstuffs, including cakes, biscuits, pizzas, and children's sweets.