The number of children who have never had an alcoholic drink has increased, while fewer children have ever smoked a cigarette, according to the Irish Health Behaviour in School-aged Children 2014 report.
58% of children surveyed have never had a drink, compared with 52% in 2010, while the proportion of those who have ever smoked a cigarette fell from 28% in 2010 to 16% last year.
Since 2010, more children are also eating fruit, 23% compared with 20%; eating vegetables more than once a day, 22% compared with 20%.
Fewer are eating sweets or drinking soft drinks.
However, there has been a disimprovement in the number of children who report having gone to bed hungry (22% in 2014 compared with 21% in 2010) and in the number of children exercising four or more times a week (52% in 2014 compared with 50% in 2010).
In terms of physical activity, significant differences are seen when the figures are broken down by gender.
For example, 30% of boys reported being physically active every day compared to 16% of girls.
More young children also reported being physically active compared with older children.
This is the fifth study of its kind.
Ireland is one of 44 countries that carries out this research.
It involved 230 schools and 13,611 children aged between ten and 17.
In relation to smoking, the number who said they were 'currently smoking' is down from 12% in 2010 to 8% in 2014.
However, 30% of those aged 12-17 reported it was easy to buy cigarettes where they live and go to school and 59% reported that it was easy to get someone else to buy cigarettes for them.
The number of children who reported having been 'really drunk' fell from 31% in 2010 to 21% in 2014, and the number of children who had reported being drunk in the past 30 days was down from 20% to 10%.
It was the first time that questions designed by children were included in the study.
They included a question on whether children felt self confident. It showed significant differences between boys and girls, with 66% of boys reporting always or often being self-confident compared to just 35% of girls.
Other questions designed by children included if they always love their family (84% of boys compared to 89% of girls), whether they always felt comfortable with friends (72% of boys compared to 68% of girls).
Overall, more children are trying to lose weight (16% compared to 13% in 2010).
The number of children who reported being in a fight in the past year was down from 34% in 2010 to 29%.
The number of children who said they had bullied others was down from 16% to 13%, however the numbers who reported being bullied increased slightly from 24% to 25%.
It was also the first time cyberbulling was included.
13% reported being bullied by being sent mean messages, or having them posted about them.
15% said someone had taken an unflattering or inappropriate picture of them and posted it online, with 19% of girls saying they had suffered that kind of abuse compared to 11% of boys.
27% of those aged 15-17 reported that they had had sex.
Of those 33% reported using birth control the last time they had sex, and 73% reported using condoms.
