In the past few years the market for so called ‘energy drinks’ has exploded. Full of sugar and caffeine, there’s now around a dozen energy drinks on the market, and they’re very popular with kids.

“I’ve had Rockstar,” says Hunter, 13.

Thirteen-year-old Will’s favorites? “Monster, Rooster Booster.”

“Sobe’s Adrenaline Rush,” answers T-J, 14.

“It tastes very good,” explains 16-year-old Corrissa, “It gives me energy.”

Energy, according to some of the marketing, that makes these drinks good for school or sports performance. “They do kind of imply they’re sports drinks,” says Nutritionist Elizabeth Redmond, Ph,D., “but a sports drink like Gatorade or something would hydrate you. And these drinks have a lot of caffeine, and they’re actually going to have a diuretic effect and can dehydrate.”

And while the caffeine in many of these drinks, the amount in an average cup of coffee, gives kids a boost, a couple hours later, they crash.

“Yeah if I drink one I might be kind of hyper for a while and then I’ll be like ‘Ehhhh’ and get real tired,” explains 12-year-old Luke.

Experts add the side effects of caffeine also include loss of appetite, moodiness, headaches, nausea, difficulty sleeping.

And while there hasn’t been any long term studies on the effect of regular caffeine use by kids, Redmond explains that, “Once you get used to the caffeine boost you’re going to want to keep getting it. But it’s just not a healthy lifestyle that you want to get into.”

Experts say parents should teach kids caffeine can be addictive, and that if they’re looking for better performance, there’s a much better way. “Getting enough sleep, being hydrated and eating a healthy diet would be the three biggest things you’d want to look at if you wanted to get more energy to do better at sports,” says Redmond.

Caffeine can be found in everything from chocolate bars to over-the-counter analgesics, from cold remedies to weight-loss pills, and from coffee to energy drinks. Sufi priests made the first caffeinated drink out of coffee-bean husks, then used the liquid to fuel all-night religious ceremonies. Early Europeans witnessing these maniacal events dubbed the participants "whirling dervishes."

While other favorite teen beverages such as soft drinks and high-energy drinks also contain caffeine, ounce for ounce they can't match the high level of caffeine in brewed coffee. Some link the popularity of frozen coffee drinks such as the Starbucks Frappuccino and Caribou Cooler to the current craze for caffeine among teens who begin with these milkshake-like beverages and soon move on to hot drinks, eventually graduating to espressos on their way to becoming coffee connoisseurs.

Caffeine isn't a drug on par with amphetamines or cocaine because it doesn't act on the areas of the brain related to reward, motivation and addiction. Caffeine, however, is by far the most widely used psychoactive drug in the world, easily surpassing both alcohol and nicotine. A study of java-drinking trends by the National Coffee Association showed that, as of 2000, a record 79 percent of U.S. adults consumed coffee.

Caffeine's molecular structure is very similar to that of adenosine, an inhibitory brain substance found in many animals, including humans. Animal studies show that adenosine could be somnolent, or sleep-inducing. When people need sleep, their adenosine levels are high, which seems to trigger the brain into wanting to shut down. The longer you're awake, the more adenosine gradually accumulates in your brain. This surplus binds to specialized adenosine receptors, depressing nervous-system activity and making you groggy. Getting sufficient sleep clears the chemical from your system. An alternative to clearing adenosine – you can block it before it has a chance to make you sleepy. Caffeine does this by binding to adenosine receptors before the adenosine gets there. Consider the following:

• The coffee industry rakes in an estimated $18 billion per year.
• As a nation, we down 350 million cups of coffee a day
• The number of teens drinking coffee in restaurants or cafes has increased 12 percent this year and 15 percent in the previous year.
• Caffeine has no nutritional value, is not needed for any physiologic function, and is commonly abused by the tired and stressed.
• Coffee can sometimes trigger gastrointestinal distress.

Caffeine is a drug. It can disrupt teenagers' already erratic wake-sleep cycle, which can have harmful effects on short-term memory and learning ability and can lead to decreased productivity, negative mood, loss of behavioral control, depression and an increase in impulsiveness. A large caffeine intake can lead to increased heart rate and increased blood pressure in teenagers. Caffeine’s effects on teenagers can be greater than on adults because of teens' varying tolerance levels and low body weight.

It's important to understand that caffeine causes physical dependence in its users, meaning users go through withdrawal symptoms, which can range from throbbing headaches to fatigue to irritability. Consider the following:

• Caffeine is a drug that affects mood, behavior and the nervous system.
• Teens who drink coffee socially should drink decaf coffee or half and half to avoid the harmful effects of caffeine.
• Teens should consume no more than three caffeinated beverages or one super-caffeinated coffee beverage per day.
• For those hoping to ace a critical exam through a short-lived boost in IQ, the current evidence indicates that caffeine doesn't make you smarter.
• Caffeine can have a dramatic effect on alertness but as you move to higher-order cognitive functioning, such as decision-making, it has little impact.
• Know that caffeine comes in many forms. There's a new caffeinated gum on the market: Jolt Caffeine Energy Gum. According to its website, two pieces of gum are capable of releasing in just five minutes the same amount of caffeine as in a cup of coffee.