From Our 2007 Archives

Energy Drinks Pack a Caffeine Punch

Analysis Shows High-Calorie and High-Caffeine Content in Each Bottle or Can

By Jennifer Warner
WebMD Health News

Reviewed By Louise Chang, MD

Aug. 6, 2007 -- "Energy drink" may sound healthy, but downing one of the new carbonated energy drinks may give you more of a caffeine and sugar buzz than you bargained for.

A new review in Consumer Reports analyzed the caffeine and calorie content of a dozen popular energy drinks and found caffeine levels, which often aren't listed on the label, can top 200 milligrams per bottle or can. Meanwhile, the calorie count may reach up to 260 calories.

Researchers say a big part of the problem has to do with serving size. Many energy drinks list their nutritional content on the label per 8-ounce serving. But the bottles or cans they're sold in often contain more than that and few people stop drinking halfway.

Behind the Buzz of Energy Drinks

Researchers say U.S. consumers spent $744 million on caffeinated energy drinks in the last year, a 34% increase over the previous year.

The energy drinks are heavily marketed toward young adults, but they contain stimulants that make them unsuitable for young children and pregnant women.

The analysis shows caffeine levels per 8-ounce serving ranged from 50 milligrams in Archer Farms Energy Drink to 145 milligrams in Celsius Energy Supplement. In comparison, a cup of coffee contains about 100 milligrams of caffeine, and a 12-ounce Coca-Cola has about 24 milligrams.

Up to 300 milligrams per day is considered safe for most adults, but children are advised to keep their caffeine intake to fewer than 100 milligrams per day.

Meanwhile, the calorie content ranged from fewer than 10 calories per 8-ounce serving among the low-calorie energy drinks (Enviga Sparkling Green Tea, Tab Energy Drink, Celsius Energy Supplement) to 130 calories per serving of the higher-calorie energy drinks (Rockstar and Sobe No Fear).

Most of the drinks listed at least one caffeine-related stimulant, and some have ingredients, like ginseng, that may amplify caffeine's effects.

Researchers say the bottom line is that an occasional energy drink is fine for most people, but do the math and avoid overindulging.

SOURCES: Consumer Reports, September 2007; p 6. News release, Consumers Union.

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