A new study found that most kids in the United States are not drinking enough water, thus increasing their risk to physical, emotional, and mental problems.

Researchers at Harvard School of Public Health reviewed the data of more than 4,000 children with ages 6 to 19 between 2009 and 2012. The data was provided by the U.S. Centers of Disease Control and Prevention.

The team used urine osmolality to determine the concentration level of the urine of the participants. The urine color of a well-hydrated person is a pale yellow while a dehydrated person is dark yellow.

The analysis showed that more than half of the participants were not getting drinking enough water, especially the boys that account to 76 percent of those who were not well-hydrated. The researchers also found that 3 of 4 children and teens were not drinking plain water at all.

"These findings are significant because they highlight a potential health issue that has not been given a whole lot of attention in the past," Erica Kenney, lead author and postdoctoral research fellow in the Department of Social and Behavioral Sciences at Harvard Chan School, said in a university news release. "Even though for most of these kids this is not an immediate, dramatic health threat, this is an issue that could really be reducing quality of life and well-being for many, many children and youth."

The researchers recommend programs that would encourage children to drink more water to improve their health and performance at school.

One expert, who wasn't part of the study, wasn't surprised of the results.

"During the school day, access to water may be limited, and many children may even avoid consuming water because they prefer not to use the bathrooms at school," Dr. Ron Marino, associate chair of pediatrics at Winthrop-University Hospital in Mineola, N.Y., told HealthDay News. "This may stem from lack of privacy, embarrassment, or even bullying or other risks associated with being in the bathroom."

Marino added that the food industry is also a contributor because of the juices, sports drinks and sodas that are more appealing to the children than plain water.

The study was published in the June 11 issue of the American Journal of Public Health.