The survey, which examined the attitudes of almost 16,000 young people, found that more than a third of boys aged 14 and 15 did no homework at all.
Yet 29 per cent of boys of the same age cited school and career problems as their principal worry. In contrast, female pupils said that their greatest worry was their appearance.
The research, by the Schools Health Education Unit, found that 20 per cent of 14 and 15-year-old females had eaten nothing for breakfast, and 18 per cent had not had any lunch. And 39 per cent of 10 to 11-year-old boys had not heard of HIV or Aids.
David Regis, author of the report, said: "It was previously thought most important to educate young people about HIV. But we now know that young people are more likely to be affected by other sexually transmitted diseases, so teachers may be more likely to talk about those."
"Young People in 2001" is available from the Schools Health Education Unit, at pound;45. http:www.sheu.org.uk