More 15 to 17-year-olds are having sex.

The Health Behaviours in School Children survey shows an increase from 23% in 2010 to 27% in 2014.

The survey is a World Health Organisation collaborative study that takes place every four years.

The overall proportion of children who reported being in a physical fight has decreased from 2010 but more girls and older children report being victims of cyber bullying.

Overall health levels among Irish school children are good.

The survey shows that reported levels of fruit and veg consumption have increased since 2010, while consumption of sweets and soft drinks have decreased.

But the report also shows worrying levels of children going to bed hungry and skipping breakfast.

There was an overall decrease in reported levels of smoking and drunkenness and an increase in levels of never drinking between 2010 and 2014.

Many children reported that it is easy to buy cigarettes or get someone else to buy cigarettes for them.

20% of children say they don't wear seatbelts.