Celia Hassan starts each day by reaching into her fridge and opening a can of Monster Energy.

“I crack one open every morning like clockwork,” said Hassan, a 21-year old political science major at Reed College in Portland, Oregon.

At a time when national attention is being focused on energy drinks that contain alcohol, which have been banned in several states, the non-booze brands like Hassan favors are not getting much publicity.  But that hasn’t made them less widespread–or less controversial.

According to the Mintel International Group, non-alcoholic energy drinks are enormously popular.  The marketing analysts say 31 percent of 12- to 17-year-olds and 34 percent of 18- to 24-year-olds report they regularly consume energy drinks.

Hassan said she started downing them when she was 14 years old to keep her going through a busy schedule of school and athletics. 

She’s been hooked ever since and even started a Facebook page, “Admitting You Have a Problem: The Energy Drink Addicts Support Group.”  Started as a joke, Hassan says she was surprised when the group grew to its current 118 members. The page is filled with comments from people unapologetically professing their energy drink addictions.

Some researchers, however, worry that people are uninformed or misinformed about the ingredients in energy drinks and their possible effects.

“We talk with students a lot and they don’t really know what’s in (energy drinks),” explained Patricia L. Maarhuis, a coordinator at Washington State University’s Alcohol and Drug Counseling, Assessment, and Prevention Services (ADCAPS).

Energy drinks are marketed as nutritional supplements and are therefore not regulated by the U.S. Food and Drug Administration–which worries Maarhuis.

Many of the beverages are advertised as containing “natural” or “herbal” additives such as taurine, an amino acid that may or may not be a mood enhancer (the research is mixed) and stimulants such as guarana or ginseng.  But “they’re not required to tell the consumer what’s really in there so we really don’t know,” Maarhuis said.

What is known, according to a report by ADCAPS , is that the “energy” in energy drinks is really “sugared water with a lot of caffeine,” that delivers a buzz along with a can of empty calories.

According to the report, some energy drinks contain up to 200 milligrams of caffeine.  By comparison, a 1 oz. shot of espresso contains about 30 – 50 milligrams of caffeine. And energy drinks average about 200 to 260 calories, which the report notes is the equivalent of eating a large candy bar or two hot dogs.

All of this is big business; two years ago the energy drink industry’s total U.S. sales reached $4.8 billion, according to the Department of Food Science and Human Nutrition at the University of Illinois, and sales have likely grown since then, with big companies like Coca Cola, PepsiCo, and Starbucks Coffee getting in on the action and releasing their own brands. The Institute of Food Technologists predicts the energy drink market will be as much as $19.7 billion by 2013.

The ADCAPS report notes that one marketing technique has been for companies to sponsor parties on college campuses, offering to supply drinks as mixers.  And the trend of mixing non-alcohol energy drinks with beer and hard liquor inspired companies to offer the pre-mixed malt-based beverages that are now being targeted by local regulators as potentially dangerous.

Health problems associated with too much caffeine — increased heart rate and blood pressure, insomnia, and anxiety –are also linked to energy drinks, Maarhuis said.  She added that some people with sleep problems may not realize that energy drinks are contributing to the problem because they are unaware of how much caffeine they’re getting.

None of this fazes Hassan, who proudly continues to consume energy drinks daily.

“Everyone tells me energy drinks aren’t good for you,” Hassan said. “But I’ve been drinking them since I was 14 and I’m in great shape.”

She admits that she is mostly unfamiliar with what’s in energy drinks and what effects they can have but doesn’t really care so long as they work.  “I get a really bad headache if I don’t have one,” she said. “I’m not functional unless I have an energy drink.”