A soft drink that burns calories? Coca-Cola Co. has just introduced one. But don't throw away your Weight Watchers plan.
In a conference call this week, the Atlanta beverage giant unveiled plans to launch Enviga, a sparkling green tea-based soft drink infused with a tantalizing claim: Consume three 12-ounce cans of Enviga over a 24-hour period, and a healthy person of normal weight can burn anywhere from 60 to 100 additional calories. Coke developed the beverage in partnership with Nestle SA.
An executive of the companies' joint venture called the new product a "breakthrough" concept. And the prospect of a drink that could actually melt pounds away set off a mini media frenzy. In a five-minute segment Thursday, NBC's "Today" show led its report on the new drink with the question, "Miracle Beverage: Can Coke drink burn calories?"
But Enviga -- which will make its first appearance on U.S. store shelves in parts of the Northeast next month, hits stores nationwide in February and then may expand to Latin America, Europe, and Asia later next year -- is no quick fix for a bulging belly.
The science behind Coke's claims -- a study funded by the Coke-Nestle partnership and led by a researcher at the University of Lausanne, near Nestle's Swiss headquarters -- depends partly on research that hasn't been publicly released or formally reviewed by other scientists. But Coke says the study, along with similar research in recent years, supports its assertion about calories burned as a result of drinking Enviga.
The study included only healthy, normal-weight men and women from the ages of 18 to 35 -- people who, by definition, don't need to lose weight. The researchers measured the energy expenditure of the 32 participants by putting them in a metabolic chamber, a small room where scientists can determine subjects' metabolic rate by measuring the heat released from their bodies. The subjects drank a placebo and then drank Enviga, along with eating a healthy diet and doing some exercise, Coke said. Coke says it didn't measure the drink's effects on overweight people.
Assuming the calorie-burning benefit is real, Enviga raises another question: Is it worth the $1.29 to $1.49 price of a 12-ounce can? Assuming a 60-calorie loss from three cans of the drink, a person would have to drink more than five cans a day of Enviga, at a cost of $6.45 or more, to burn the number of calories found in two Oreos. A brisk 15-minute walk would do the same trick. To accomplish a more substantial health benefit -- such as erasing the effects of a McDonald's Big Mac -- a person would need to drink about 28 cans of Enviga, at a cost of $36 or more.
Many nutritionists endorse drinking green tea, which naturally contains some caffeine, but some are skeptical about whether three cans a day of Enviga would be worth the effort and expense. "It's so easy to get 100 extra calories out of your diet," said Chris Rosenbloom, a nutrition professor and associate dean of the College of Health and Human Sciences at Georgia State University. (She also is a member of an advisory board for the Gatorade Sports Science Institute, a part of Coke rival PepsiCo Inc.) "I don't know that this is going to be the answer that people are looking for," she says.
Rhona Applebaum, Coke's chief scientist, agrees that the new drink is not a diet pill. "This is not a magic bullet," she says. Enviga should be consumed as part of a healthy diet and regular physical activity, she says. Enviga "gently invigorates your metabolism. It gives your body this extra boost."
Studies have yet to establish major health gains from drinking green-tea. Several studies, some still ongoing, have probed potential health benefits, such as whether a component of green tea, an extract called epigallocatechin gallate, or EGCG, could kill leukemia cells or fight heart disease.
In May, the Food and Drug Administration rejected one company's attempt to put labels on its product touting green tea's ability to help reduce risk factors for cardiovascular disease, citing "no credible evidence" to support the claim. The agency in 2005 also reviewed claims that green tea may fight certain forms of cancer, but found no evidence of benefits there, either.
Green tea's effects on calorie burning have also been probed in several studies: One 1999 paper in the American Journal of Clinical Nutrition, led by a researcher at the University of Geneva in Switzerland and cited by Coke, concluded that in a small study EGCG appeared to promote "fat oxidation."
Coke didn't petition the FDA to make a formal "qualified health claim" because the product doesn't assert an effect such as reducing a disease or a health-related condition, Coke's Dr. Applebaum said. "We're not making any weight-reduction claims," she said. The calorie-burning assertion is instead a "structure-function claim," which companies are permitted to make as long as they can back their claim up with science and vouch that the information on the label is truthful, Coke and the FDA say.
And while overweight people are the logical market for a drink that promises to burn calories, Coke says it hasn't tested the drink's effects on them. She said the Coke-Nestle partnership plans further research on the drink's effects.
Coke is late to the green-tea party. Green tea is derived from the same shrub (Camellia sinensis) as black tea and has long been believed to contain medicinal powers.
Indeed, Coke is mired in fourth place in the overall U.S. ready-to-drink tea category. Arizona Beverage Co., PepsiCo's Lipton, and Cadbury Schweppes PLC's Snapple have been selling green teas with far more success for some time. Pepsi didn't pass up the chance to take a swat at its rival, suggesting Coke was trying too hard by touting a green tea as a calorie-burner. "People know and trust the health benefits of tea," said Dave DeCecco, a spokesman for the Pepsi and Unilever NV's tea partnership. "Anything more is like smothering a Kobe steak in ketchup."
The EGCG content in Enviga is several times higher than that of other green-tea products, because the drink is made from proprietary tea leaves from a plantation in India, Coke says. Enviga contains 100 milligrams of caffeine, or about the same amount as a five-ounce cup of coffee; a 12-ounce Coke has 34 milligrams of caffeine. Enviga contains five calories per can, which Coke says have been taken into account in the estimated number of calories that the product can help burn. Coke says it hasn't documented any increased benefit to drinking more than three cans of Enviga a day. The researchers will publicize the findings of their Enviga study at a scientific meeting starting Oct. 20 in Boston.
The people most likely to try Enviga will be young people who tend to obsess over the next cool concoction -- most of whom aren't overweight, says Georgia State's Prof. Rosenbloom. "You know who's going to be drinking these," she says. "The thin girls."