Students use the caffeine in energy drinks as a means to stay awake, often with detrimental results, experts say.

“It’s a stimulant — these kids are wired and they’re not getting enough sleep anyway,” said Beverly Sedlacek, assistant professor for psychiatric nursing at the University of Alabama in Huntsville. “We are a nation that is really sleep deprived. That sets us up for other kinds of addiction that can be avoided.”

Caffeine is not a substitute for sleep, said Beth Kitchin, assistant professor in the University of Alabama at Birmingham Department of Nutrition Sciences.

“One of the things I’m most concerned about is I think a lot of people are using this as a means to get by on less sleep,” she said.

Activities, studies, competition are sometimes limiting students and adults to sleeping from midnight or 12:30 a.m. to 6 or 6:30 a.m., Kitchin said.

“They’re using caffeine to keep that process going,” she said. “What’s happening is you have a lot of sleep deprived people.”

Three-quarters of adolescents report drinking at least one caffeinated beverage daily, and nearly one-third, 31 percent, consume two or more such drinks each day, according to The National Sleep Foundation’s 2006 Sleep in America study of children in 6th through 12th grades. The study also found: “Not surprisingly, teens who drink caffeinated beverages get less sleep than those who don’t.”

Just one in five adolescents get an optimal nine hours of sleep on school nights; 45 percent sleep fewer than eight hours on school nights, according to the study.

That loss of sleep is harmful because sleep is a time for the body to rejuvenate, Kitchin said.

“We may be setting ourselves up for some bad chronic diseases later in life,” she said. “Most people say, ‘I can get by on six hours.’ Getting by and being healthy are really two different things.”