A new study shows that kids drink more water when they have easy access to it.

The amount of water one needs to drink per day varies depending on the age, weight and gender. Most kids drink plenty of juice and milk per day, but water is essential as it improves digestion, prevents constipation and improves blood circulation. It can also protect them from being overweight or obese.

Researchers at the New York University School of Medicine installed water jets in 10 New York City public schools in 2010 to determine if easy access to drinking water can make kids drink more. They monitored the kids' drinking habits during lunch three months after the installation and ten months later. The observation was compared to the data prior to the installation of the water jets.

The team also surveyed the kids and the cafeteria managers to get their opinion on water jets. The kindergarten students were also asked about their water intake and if they think that the water is safe and clean.

The analysis showed that prior to the installation of the water jets, only 10 percent of the kids drink water during lunch. The number increased to 34 percent when they had access to drinking water. The rate remained consistent even after the study period.

Water also started replacing the drinks of other students that started at 31 percent without the water jets, but fell to 23 percent after the installation.

Cafeteria managers found the water jets easy to clean and install.

"Water is free, and freely available from fountains, but I think that the jets are more attractive to use." Kristen E. D'Anci, a psychology researcher at Tufts University, who was not involved in the study, told Reuters Health by email.

The study had one limitation though, as it failed to look at if kids preferred water over sugary drinks. The researchers defended that the goal of the study was to devise an effective means to make kids drink more water.

 "The idea is to make the healthy choice the easy choice," said Brian Elbel, lead author of the study. "Of course you can lead a kid to water but you can't always make her drink."

This study was published in the Dec. 18 issue of the American Journal of Public Health.