LA CROSSE, Wis. -

A new investigation may have you thinking twice before reaching for that next energy drink -- or letting your teen reach for one.

The U.S. Food and Drug Administration is investigating five deaths with one thing in common: all of the deceased drank Monster Energy Drinks before they died.

Last week, the parents of a 14-year-old girl in California who died after drinking two mega-size Monster Energy Drinks in 24 hours filed a wrongful death suit.

The FDA said the fact that it's doing the investigation into those five deaths does not prove Monster Energy Drinks were the cause.

Monster said its drinks did not cause those deaths, but the attention the investigation is getting is shining a spotlight on the potential risks for young people.

Not everybody's heart handles that concentrated dose of caffeine the same way. That's especially true for young people.

"The body size can make a difference. So the smaller a person is, they can't break it down or metabolize it as well or as quickly as somebody whose body is larger," said Gundersen Lutheran internal-medicine physician Amanda Strosahl.

Plus, adults may have had more time to develop a tolerance for caffeine.

Logan High School senior Ben Belzer has been drinking energy drinks since middle school.

"It's kind of like this whole culture with the energy drinks. They just seemed like a cool thing to try out,” said Ben with a laugh. “I feel like I'm describing a drug or something.”

Administrators at Logan High are doing what they can to keep energy drinks out of students' hands, at least while they're at school.

No energy drinks are sold on campus, and students aren't allowed to bring any drinks from home to school, other than water.

"These types of drinks are promoted very heavily out in the media. And I think us, as education officials, the best that we can do is just promote the healthy eating and drinking habits," said Logan Dean of Students Wally Gnewikow.

"It would be convenient if I was able to go out and buy a Red Bull from the cafeteria or something instead of having to go to Kwik Trip or something. But I mean, I totally understand the policy against it and the sort of stigma it has with it," said Ben.

But Gnewikow said there's only so much a school can do once students leave the classroom.

"We can't run everybody's lives away from school. We can just do what we can do here on school grounds," said Gnewikow.

In the short run, an energy drink consumer may not feel any negative health effects. But Strosahl said in the long run, the large amount of sugar and calories can contribute to health problems like obesity and diabetes.

An energy drink can contain two or three times as much caffeine as a cup of coffee.