Experts are concerned that Britain's youth are prepared to take risks with their health.

The Health of Young People survey is the most comprehensive ever commissioned by the Department of Health.

The survey painted a grim picture of Britain's youth with smoking, drinking and obesity commonplace. Twenty-three per cent of young men and 19% of young women are overweight, and 6% and 8% respectively are obese, according to the survey.

However, the research also uncovered evidence that many young females, aged 16-24, worry unnecessarily about their weight.

The survey found young women tended to perceive themselves as overweight when they were not.

Among those with a desirable weight, 20% said they were too heavy and 45% were trying to lose weight.

Even among underweight women 10% were trying to lose weight.

Chief medical officer Professor Liam Donaldson said: "Weight at all times of life is a particularly important predictor of health. If you are very overweight you run a risk of developing a heart attack or a stroke.

"The fact that a high proportion of children are overweight and 10% are obse is a worrying finding.

"But we found a group who, despite being below their ideal weight, were still trying to lose weight.

"That was particularly adolescent girls. We know about the problems of eating disorders and perception of body image among young girls, and this was a particuarly worrying finding to find it confirmed in such a striking way in the survey."

The survey also found that among the 16-24 age group:

• The proportion of young men who smoke increased from 20% at age 16 to 40% at age 18. For young women the proportion was higher at age 16 (25%), but lower at age 18 (30%);
• The prevelance of cigarette smoking was much higher in lower social groups;
• The proportion of young men who reported drinking on at least three days a week increased from 10% at age 16 to 53% at aged 21, and then declined to 42% at age 24. The corresponding percentages for young women were 6% at age 16, 32% at aged 21 and 18% at age 24;
• Over half (53%) of young men aged 18-24 said they had exceeded four units of alcohol at least one day a week, and one third exceeded eight units at least once a week. Among women, 28% exceeded three units and 13% exceeded six units at least once a week.

Children

Among children aged 2-15 poverty was a major factor in health.

The survey found:

• Problems with children's psychological well-being are "significantly" linked to low income;

• Poor dietary habits are more likely among children in lower social groups;

• Children from households with a low income are more likely to suffer from poor health.

The survey also found that 29% of girls and 44% of boys under the age of 15 did not take part in physical activity lasting 30 minutes outside organised sessions at school.

Smoking was more prevalant among children who came from households where at least one parent smoked (24%) compared with those from no smoking households (7%). However, nine out of ten children rated their health as "good" or "very good".

All young people

Among all young people males were more likely to suffer major and minor accidents than females.