Almost one in four Irish 13-year olds are overweight or obese, a new survey has shown.

The survey found that found that 60% of 13-year-olds exercised six or more days every two weeks.

The 'Growing Up in Ireland' study also found that almost 40% of girls in this age group were trying to lose weight.

Around 7,500 13-year-olds were surveyed - the study previously surveyed the children when they were nine years old.

The study also found that the number of families experiencing money difficulties had doubled since they were previously surveyed as part of the ongoing study.

Some of the main findings were:

* 60% of 13-year-olds exercised six or more days in the last 14 days – boys were more likely to exercise than girls.

* Higher levels of exercise were more common among children from socially advantaged backgrounds.

* Most young people maintained a healthy body weight over time, but 26% were either overweight or obese at 13 years – 20% were overweight and 6% obese.  Girls were more likely to be overweight or obese than boys (30% vs 23%).

* There were some changes in weight status between nine and 13 years of age.  Relatively few (11%) non-overweight nine-year olds had developed weight problems by the age of 13. However, those with weight problems at nine years of age tended to maintain them.

* Just over half who were overweight at nine remained overweight at 13, with 11% becoming obese. Girls were more likely than boys to maintain weight problems.

* Dieting behaviours were evident among 13-year-olds. Girls (39%) were more inclined to report that they were trying to lose weight than boys (30%).

* Children with weight issues were trying to do something about it – 78% of children who were obese were exercising to lose weight (compared to 39% of those who were not overweight or obese).

* 19% of 13-year-olds live in one-parent families. In general, the structure of families is stable over time, though there have been changes from one-parent families to two-parent families and vice-versa over the four years between interview.

* About 4% of children in the age-group went from a two-parent to one-parent family between 9 and 13 years while another 4% went from a one-parent to two-parent unit.

* Almost all 13-year-olds indicated that they got on well with their parents.  The majority felt that parents spent time talking to them; could be counted on if they had a problem; did fun things with them and that their parents respected their privacy.  More young people spent time talking to their Mum (70%) than to their dad (60%).  In contrast, more young people did fun things with their dads (72%) than their mums (63%).

* 46% of 13-year-olds had discussed sex and relationship issues with their parents – more girls (51%) than boys (42%).  Mothers were the main source of information (32%).  Only 6% of 13-year-olds mentioned their father as the main source of information.

*91% of 13-year-olds had never smoked and 2% said they smoked at the time of interview but a further 7% have tried it at some time.  A slightly higher percentage of girls than boys said they smoked.

* 15% of 13-year-olds said they had tried alcohol.  There was really no difference in the rates between boys and girls. 

* Only very small proportions (just over 0.5%) said they drank once a month or more. 83% of 13-year-olds had regular spending money – an average of just under €9 per week. Most 13-year-olds said they get the money from their parents as they need it. Girls were more likely than boys to say they get spending money for doing chores.