For many adolescents, caffeine is a regular part of their diet

Parents reported that their teens consumed caffeine most frequently at home (81%), followed by eating out (43%).

Consumption differs according to age group. More parents of 16 to 18 year olds than 13 to 15 year olds reported daily caffeine consumption – 14 percent versus 6 percent. And parents who said their children drank caffeinated beverages zero to three days a week (74%) attributed this to the fact that they generally did not consume caffeinated beverages at home or that their teen was trying to be healthy or didn't want their sleep disrupted.

Two-thirds of parents said they believe they know if their child is consuming too much caffeine.

Experts suggest a limit of 100 milligrams per day, or less, for teens, which is roughly the amount of caffeine in an eight-ounce cup of coffee or a little more than two 12-ounce soft drinks. One in three parents in the survey thought the limit was higher than that.

Caffeine is a stimulant that can help with alertness, concentration and energy. However, long-term use, especially among adolescents, may cause problems. “Excessive caffeine consumption in adolescents can affect their mood, sleep, and school performance, as well as cause side effects such as headaches, stomach upset, or heart palpitations,” according to a press release from CS Mott Children's Hospital.

It's also possible for teens to become addicted to caffeine. “Parents can ask the adolescent's health care provider to explain the risks of caffeine and suggest strategies to reduce it,” the authors write. “Plus, parents can involve their teen in selecting caffeine-free options to have at home.”

This article is part of the Post's “Big Number” series, which takes a brief look at the statistical side of health issues. Additional information and relevant research is available via the hyperlinks.