The scientists have surveyed 10275 school children, grades, 1-12, and found that the higher caffeine intake harmed children's sleep and physical activity.

The study examined the students' intake of 19 caffeinated food items and found that caffeine consumption of more than half of UAE's children to be higher than the safe limit of 100 milligrams (mg) per day for healthy children.

For healthy adults, the safe limit is 400 mg of caffeine a day.

The study is part of a research project the university is conducting to measure caffeine intake and its possible impact on the country's school children.

The main source of caffeine for the school children are Latte coffee (11.63%), followed by instant coffee (11.04%), and espresso (10.83%), the study finds.

The researchers show that most students (74%) with high caffeine intake slept less than 8 hours per night, and the risk of sleeping less than 8 hours increased significantly by 2.6 times when consuming caffeine.

The recommended sleep duration for children ranges from 9-12 hours per day, depending on their age, according to the Center for Disease Control and Prevention (CDC).

However, the risk of difficulty falling asleep increased by 2.7 times when consuming caffeine products, the scientists maintain, adding that about 86% of the participants with low caffeine intake did not have trouble falling asleep.

Students with excessive caffeine consumption were averse to physical activity, with over 62% of high caffeine consumers exercising less than three times a week, according to the study.

The study adds that students with high caffeine consumption used smart devices more than 2 hours a day.

However, the screen time for those with lower caffeine intake, which made up 60.7% of respondents, was less than 2 hours, according to the study.

The American Academy of Pediatrics recommends a limit of an hour a day of screen time for children between the ages of 2 and 5, and two hours of non-schoolwork for school-age children between 6 and 17.

Caffeine consumption was also associated with lower grades, as 64% of students with high caffeine intake risked getting a lower GPA, the scientists reveal.

The national cross-sectional study's findings could help in establishing a proposal for interventional and educational programs promoting healthier lifestyle behaviors among children and adolescents, the scientists recommend.