However, the study also found that there is a slight drop in life satisfaction and happiness -- especially among girls.
There has also been an increase in the proportion of children who have been bullied, the research added.
The overall study aims increase the understanding of young people's health and wellbeing, health behaviours and their social context.
For the study, published on the website of Ireland government, the research team from University of Ireland conducted a survey of 15,500 children in 2018 from more than 250 primary and secondary schools.
The study also revealed the increase in the number of children reporting never having had an alcoholic drink.
There is also 5 per cent drop in the number of children trying smoking, but 22 per cent of 12-17 year olds have tried e-cigarettes.
The researchers showed that consumption of sweets and sugar-sweetened drinks has gone down by 6 per cent.
Researchers also found reduction in numbers of 15-17 year olds reporting to have had sexual intercourse, but there is also decrease in usage of contraceptives.
Of those who reported having had sexual intercourse, 64 per cent said they used a condom at last intercourse to 73 per cent in 2014.
According to the data, there was a four percentage-point drop in children saying they were 'very happy' with life to 43 per cent compared to 2014, with girls significantly less likely to b very happy than boys.