By Leslie Barrie
Updated: March 02, 2016

energy-drinksCaffeine-deprived fast-food customers will soon have a new menu option—energy drinks. Franchises Carl's Jr. and Hardee's recently announced that theyre teaming up with Monster Energy to sell the über-caffeinated beverages in 3,000 U.S. stores. Their target customers? Teenagers.

“You can't walk down the street without seeing a young guy holding a can of Monster,” Andrew Puzder, the CEO of CKE Restaurant group, the parent company of both restaurants, said in a news release. “Now guests can start their morning with one of our delicious breakfasts and cap it off with a can of Monster to get a head start on the day, or they can have one after their burger to keep them going.”

These two fast-food restaurants arent the first to add the stimulant-packed beverages to their quick-serve menus. In July, Southeastern chain Krystal introduced the industrys first branded energy drink with a kid-friendly name: The Krystal Blitz is served either “frozen” or “on the rocks” (language that conjures up images more fitting of a bar than the drive-thru).

Targeting this young demographic might be a smart financial move for fast-food restaurants. The number of energy-drink users has skyrocketed from 17.4 million to 34.5 million in the last five years, according to Mintel, a market research group. Plus, it's mainly young adults who are consuming the cans. Although beverages like Coca-Cola and Pepsi continue to have a significant upper share, according to one report, the same report found that traditional soft drinks (containing about one-fifth the caffeine of a Monster) were on the decline, losing 15.6 million adult drinkers in five years.

So, what about the health of these juiced-up kids who are being targeted? A typical 16-ounce can of Monster has 160 milligrams of caffeine, almost double what you'll find in your average cup of joe. If youngsters consume two of these cans in one day, theyll surpass their advised daily caffeine limit of 300 milligrams by 20 milligrams.

Even though a 2001 study in the Journal of Amino Acids found that Red Bull may improve concentration, energy drinks can still be dangerous. Heavy caffeine use—between 500–600 milligrams a day—can cause anxiety, insomnia, dehydration, stomach woes, or a dangerously fast heartbeat in some people. A number of youngsters have felt these effects. In 2008, for example, four middle school students from Broward County, Fla., downed the energy drink Redline and were rushed to the emergency room with heart palpitations.

In light of rising obesity rates, throwing back two cans may bring up other nutritional issues. "Not only are the caffeine levels in these drinks super high, but theyre also loaded with sugar," says Frances Largeman-Roth, RD, the senior food and nutrition editor at Health magazine. "The fact that these beverages are pushing out more nutritious things like low-fat milk and fruit juice is a clear problem, because this age group is already calcium deficient—especially young women and girls."

Fast-food menus are already laden with diet traps, so quick-serve restaurants and energy drinks may be an imperfect combination. But not everyone thinks the partnership is a bad idea: “Carl's Jr., Hardee's, and Monster are made for each other,” Puzder said in his statement.