With the Olympics a month away, Britain's leading middle distance runner has warned that many of the country's top male athletes are risking their health by starving themselves in an attempt to run faster. His concern is shared by the British Olympic team's doctor, who says that disordered eating is common among male athletes.

Michael East, the Commonwealth 1500 metre champion who will be representing Great Britain in Athens next month, believes that many of his male contemporaries have developed a dangerous obsession with undereating that often verges on anorexia. He believes it is taking its toll on their bodies as well as affecting their performance on the track.

The 26-year-old from Portsmouth claims that, in a desperate attempt to recreate the glory days of the 1980s when Sebastian Coe, Steve Ovett and Steve Cram led the world at middle distance running, an increasing number of male athletes are cutting their calories to the point of bare subsistence.

"It used to be just women, but more and more men are obsessed with how much they weigh and what's on their plate," East says. "They think they'll get quicker if they get thinner, but they are grasping at straws. These people aren't stupid. But it's such a mental issue and I'm banging my head against a wall trying to get through to them it's not right."

Bruce Hamilton, the athletics team doctor for the Olympics, agrees that disordered eating is common among male athletes, adding: "Mike East is at the coal face, so he knows what's going on."

He says that over time, an inadequate dietary intake will mean all body systems are compromised, leaving athletes prone to stress fractures, infections and other problems.

East says of the British middle distance squad: "They can't understand why they keep getting injured, but it's obvious to me. Their bodies just haven't got the strength to deal with the training workloads, so they break down."

Around 2m people in the UK are estimated to have anorexia or bulimia nervosa; 20% of sufferers are thought to be men, a figure which is rising, says Steve Bloomfield, of the Eating Disorders Association.

Studies by Angie Hulley at the University of Leeds, which were published in the International Journal of Eating Disorders, revealed that as many as one in 10 of Britain's leading 250 female runners have disordered eating habits, many suffering from full-blown anorexia or bulimia.

Dr Hulley, a former international marathon runner, is not surprised that the problem appears to be spreading among men. "We have assumed there is less of a problem among male athletes only because there is less evidence that it exists," she says. "But they are prone to the same performance pressures as women and it is just as easy for them to get caught up in the mindset that you need to be thin to win."

Being overweight causes problems for athletes because the body must needlessly supply energy and oxygen to fuel surplus fatty tissue. Lose the extra weight and oxygen goes instead to the working muscles, enabling faster and more efficient running, Dr Hulley says. But it is easy to overstep the mark.

"There is a very thin line between an optimum racing weight for athletes and becoming too thin," she says. "Lose too much weight and you start to lose muscle mass. You become too weak to train, more prone to viruses and injuries like stress fractures and your performance goes downhill sharply."

Seven years ago, UK Athletics, in conjunction with the Eating Disorders Association, established a working party to investigate the growing problem of anorexia mainly among female athletes. Five of the seven runners representing Great Britain's junior women's team at the 1996 world cross country championships admitted suffering from an eating disorder; some of them later ended up in hospital because of their low body weight. Earlier this year a leading young British female athlete suffered pneumonia caused by organ failure - a direct result of her long-term battle with anorexia.

East says that on international trips he has witnessed male athletes "pushing food around their plates without eating it" and says he tries to "avoid sitting with them at meal times because they are so obsessed".

"Very often what happens is that a couple of athletes in a team or squad start to undereat and there is a snowball effect in that others copy them," says Alan Currie, a consultant psychiatrist at Newcastle general hospital and chairman of the UKA working party on eating disorders. "This could be what is happening among male athletes now."

With few studies having been carried out on eating disorders among sportsmen, most evidence of its existence remains anecdotal.

Colin Jackson, the former hurdler, has admitted that, at the peak of his track career, he was secretly starving himself leading up to the 1993 world championships, where he smashed the world record for the 110 metre hurdles to take the gold medal. At the time Jackson was surviving on just several hundred calories a day. "I was really frail," he says. "I was definitely bordering on anorexia."

Dr Hulley says the human body "has an amazing ability to cope with food deprivation in the short term" which is why athletes can initially train at the same intensity despite drastic cuts in their food intake. "But if someone carries on under-eating, eventually their body draws on all its energy resources and can no longer cope," she says. "The result can be devastating."

Off track: damage to the body

What happens to the body of a male anorexic athlete

· Poor circulation, especially in hands and feet

· Osteoporosis: the brittle bone disease is a side-effect of anorexia and bulimia and is often the cause of repeated injuries in athletes who persistently undereat

· A sharp drop in male fertility and libido

· A yellow tint to the skin caused by high levels of carotene in the system

· Skin bruises easily and injuries heal slowly because of a lack of appropriate nutrients

· Dental and gum problems: repeated vomiting causes a build-up of acid that can destroy the enamel on teeth

· Bulimia is the only disorder other than mumps that causes enlarged parotid glands. The salivary glands are swollen on the side of the face, giving them a round facial appearance and the mistaken belief that they are actually getting fatter

· Growth of fine, downy hair, called lanugo hair, on the face and body. This is a response to the body's attempt to provide insulation when fat levels have become too low