About 10% of the UK's 90,000 anorexics are male according to the support group Eating Disorders Association. And unlike their female counterparts they're often more concerned about building muscle than just losing fat.

'Women are meant to be slim to look good, so starve themselves (anorexia) or make themselves sick (bulimia). But the ideal male figure is toned and muscular, so more men develop eating disorders through exercising than dieting,' explains EDA spokesman Steve Bloomfield.

'Doctors often don't spot the signs in men,' he adds. 'Some think men don't get eating disorders. And what's seen in women as yo-yo dieting is regarded as normal in athletes and body builders, bulking up and bingeing on high protein foods before competitions then slimming down.'

Health psychologist Ian Williamson, who has studied eating disorders in young men, says the underlying causes for eating disorders in men are the same as for women: trauma, bullying, abuse or depression. Being a perfectionist can also increase your risk.

Adam Campbell, a fitness instructor with Hi-Life Fitness and Lifestyle clubs, began weight training at school to be more popular.

'I was very skinny when I was 14 and wanted to have biceps,' says Adam, 27. 'Building myself up was about gaining recognition from my peers - and it worked.'

But there were other emotional influences on his workout regime. 'My mother had cancer and my father left home when I was 16,' he recalls. 'Looking back, I can see exercise was a way of controlling my feelings.'

Adam's eating disorder grew more serious at university: 'I wasn't emotionally prepared for uni. The first term I went out drinking five nights a week and lived on takeaway pizza. I didn't do much sport but then someone said I'd put on weight. Soon I was working out 25 hours a week. I'd get injured but keep on going.'

At the same time, he began bingeing on junk food like burgers and chocolate. 'I once had over a kilo of chocolate in one go. Half an hour later I was on an exercise bike. I'd feel guilty and deny myself, binge again then exercise more. I was an exercise bulimic.'

But, partly because he looked healthy, Adam didn't recognise he had a problem until a year after university when he began training as a fitness instructor. 'I realised then what I'd been putting myself through,' he comments.

Adam now exercises sensibly but suspects some men he sees in the gym five or six times a week may have a problem. He now tries to ensure gym members are training safely and for the right reasons, and plans to provide counsellors for those who need help. 'Exercise should be about feeling good in yourself rather than looking attractive for others.'

— David Batty