The "snapshot" of the nation's mental health shows that 20 per cent of 16 to 25-year-olds showed signs of a problem with food.
The most common forms of eating disorder are anorexia, where patients start to starve themselves, or bulimia, in which they binge on food and then purge. Experts warn that both conditions typically start in childhood or adolescence and can vary greatly in severity.
The study also shows that one on four of those suffering from an eating disorder are men. While nine per cent of women appeared to have a problem, so did three per cent of men, the study found.
The problem of male anorexia and bullimia has traditionally been a taboo subject, but was pushed to prominence last year when John Prescott admitted that he had suffered from bulimia in the past.
Overall the study found that around 6.4 per cent of adults had an eating disorder. Another 19 per cent screened positive for a possible eating disorder and 1.6 per cent said that their feelings around food had a significant effect on their life.
Although the problem appeared to diminish with age, one woman in a 100 over the age of 75 was still thought to have some form of eating disorder.
Lucie Russell, from the YoungMinds campaign, said: "These statistics reflect a worrying trend that there is a generation of young people growing up unhappy and depressed, leading often to problems such eating disorders.
"We have to start intervening early. One in three children in every classroom has a diagnosable mental health disorder and that's just the ones that have been classified.
"There is still a huge stigma around mental health which means children and young people are not getting the support they need."