Forget Viagra the great new wonder drug to reach the UK is the new slimming sensation Orlistat. It's already been championed as a wonder drug that will allow people to eat as much as they like, and still lose weight.
But leading UK nutritionist John Garrow says the claims, made by newspapers, are extremely misleading and dangerous.
The basis of the claims was a major trial that showed the drug helped a group of obese people to lose an average of 10.3kg (22 lbs) in six months.
But Prof Garrow argues that more than half the results were achieved because the participants changed their diet.
Orlistat works by preventing the digestion of 30 per cent of dietary fat, which is excreted in faeces. So unpleasant is this that it is common for people taking the drug to reduce the amount of fat they eat which, in itself, helps reduce body weight.
Participants in the trial experienced fatty stools, increased defecation, and oily spotting. Nearly 6 per cent of those who stayed on the drug for two years had abnormally low concentrations of beta carotene and vitamins D or E (BMJ, 1998; 317: 830-1).