"Red Bull gives you wings,” asserts one TV spot. Some energy drinks sport suggestive names like Amp and Battery, others are more matter-of-fact, such as 5-Hour Energy, which comes in “shots.”

But whether they promise a boost or a buzz, what energy drinks deliver is no great shakes, according to exercise physiologist and dietitian Kara Mitchell, RD, who coordinates both the fitness and nutrition programs at Duke Health & Fitness Center.

“The central ingredients in most of these drinks are caffeine and sugar,” says Mitchell.

Forget those B vitamins some drinks tout as their secret weapon. “There is zero research supporting that these will boost energy -- it’s just the caffeine.”

The herbal ingredient guarana, commonly added to energy drinks, also contains caffeine.

Jitter Juice

A typical cup of coffee has 80 to 135 milligrams of caffeine, but some energy drinks contain two or three times that amount.

When you consider that most fans don’t stop at one little bullet can, but consume several a day, you can understand why energy drinks make nutrition experts a little nervous.

“A little caffeine is not that bad for most people, but you just don’t need that amount in your diet,” says Mitchell, who notes that heavy caffeine consumption increases irritability, raises blood pressure, and heightens the risk of irregular heart rhythms.

“You may also be masking issues like fatigue, not getting enough sleep, that really need to be addressed.”

Bittersweet News

Those seeking to enhance a workout may opt for sports drinks like Gatorade or Powerade.

They’re a safer alternative to energy drinks because they aren’t caffeinated, says Mitchell, but she recommends sticking to the lower-calorie versions and she notes that most people simply don’t need them.

“Sports drinks are meant for athletes to replenish electrolytes. If you’re sweating longer than an hour, these might be a good resource. Some enjoy the drink because it offers hydration with flavor. I have few concerns with people drinking these kinds of beverages, but you should be aware of the sugar and calorie content in the beverage you choose.”

Water + Hype = Expensive Water

Similarly, vitamin-fortified waters (like the aptly named Vitaminwater), also known as “enhanced waters,” are little cause for alarm, especially if the taste encourages you to stay hydrated.

“These may add some flavor,” notes Mitchell, “but they’re no different or better than drinking water and taking a multivitamin.”

One major difference is cost: pennies for the water and multivitamin combo versus nearly two dollars for a 20-ounce bottle of Vitaminwater.

The greatest “enhancement” here is to the company’s bottom line -- and if you opt for the full-calorie version (100 to 125 calories per 20-ounce bottle, compared to 140 calories for a 12-ounce can of Coke), your waistline.

Protein Power Takes a Powder

Protein drinks purport to boost energy and even shore up muscle, but these claims are hard for a fitness and nutrition expert to swallow.

Mitchell explains, “Protein is a source of energy, but it’s the last one; you’re going to burn carbohydrates first."

"Protein does play a role in tissue maintenance, helping the body repair the damage to muscle fibers that occurs during exertion, which is what improves strength and endurance. What gets confused is someone thinking they need to consume more protein in order to build muscle. More calories mean more fat, not muscle.”

If you really feel you need more protein in your diet, you’re better off consuming it in foods like lean meats and legumes. But most people eat plenty of protein, she notes.

“Rarely do I see anyone who needs to increase their protein intake. Most of us eat too much, while we underconsume fruits and vegetables.”

Learn how not to be fooled by food labels at Duke Medicine’s Teer House -- a great educational venue offering nutrition classes.