What Is The Best Diet Energy Drink?

Regular energy drinks are typically a mixture of water, caffeine and sugar, which adds extra calories that you can live without. However, sugar-free "diet" variations can cut the calories while still giving you a caffeine "buzz." However, experts from the Center for Science in the Public Interest, or CSPI, and MayoClinic.com stress the importance of knowing when passing over energy drinks is the best choice of all.

Energy Drink Basics

Energy drinks, with their memorable, edgy name brands and instantly recognizable packaging, are the subject of some controversy. The CSPI and medical experts, such as those at the Johns Hopkins School of Medicine, have petitioned the U.S. Food and Drug Administration to do more to regulate this so-called "functional food" by establishing the amount of caffeine or other stimulant these drinks can contain and putting warning labels on the drinks. Diet energy drinks may not all be laden with sugar, but many brands still contain excessive amounts of caffeine, which can put you at risk for caffeine intoxication. "Many so-called 'functional foods,' would be more aptly named dysfunctional foods," said Bruce Silverglade, CSPI legal affairs director with regard to energy drinks.

Choices, Choices

Data compiled from the CSPI and manufacturer's websites indicate that diet energy drinks vary widely when it comes to can size and caffeine content. On the more modest end of caffeine content is Red Bull Sugar Free, which contains 80mg of caffeine per 8-oz. serving and Tab Energy, which contains 95mg caffeine per 10.5-oz serving. Go Girl Energy drinks, marketed to women, also contain between 75 and 100mg caffeine for every 12-oz. can -- these drinks also have fewer than 35 calories. Monster Energy Absolutely Zero has only two calories per 8-oz. can, but the manufacturer only mentions guarana and caffeine as part of its proprietary "energy blend." Other Monster Energy drinks contain 160mg of caffeine for every 16 oz. Rockstar Zero Carb is another caffeine heavyweight, containing 240mg caffeine per 16 oz. can.

Caffeine Tolerance

When choosing your diet energy drink, it may be helpful to consider how much caffeine you can handle. According to the CSPI, your average 8-oz. cup of coffee contains around 133mg caffeine, although this can range between 102 and 200mg, depending on the strength of the brew. Energy drinks that have roughly the same amount of caffeine as one or two cups of coffee may not be harmful. However, many energy drinks have excessive amounts of caffeine and other stimulating substances per ounce. Moreover, these drinks are sold in cans that contain more than one serving.

None is Best

Go Girl's marketing language suggests that this low-cal energy drink is the perfect prelude to a night out on the town with the girls. Energy drinks are often used as mixers in alcoholic beverages or as a way to "sober up" or negate the effects of drinking too much booze. The CSPI indicates that drinkers who consume energy drinks assume that they're able to drive or imbibe to excess. According to MayoClinic.com, consuming excessive amounts of caffeine raises your blood pressure, and this can cause an irregular heartbeat. Consuming too much caffeine can be dangerous if you're drinking alcohol, if you're dehydrated or if you're engaging in intense physical activity.

Before You Choose

Keep in mind that the caffeine and other herbal stimulants in diet energy drinks can still have unpleasant side effects, even if they don't pose a hazard to your health. Consuming too much caffeine can cause a rapid heart rate, anxiety, nervousness, insomnia and tremors, to name only a few. MayoClinic.com indicates that between 200 to 300mg caffeine per day puts you within the moderate range of caffeine consumption, which typically won't hurt you. However, if you get more than 500 and 600mg caffeine from your energy drink, you're probably feeling more than just a little bit of an "energy" buzz.