Across the country, visions of sugarplums are fast turning into dreams of svelte physiques.
Stuffed with sweets and woozy from eggnog, millions of Americans are tugging at their waistbands, groaning in despair and resolving to lose weight this year.
Once they hoist themselves off the couch, they'll be greeted by a new beverage that promises to pave the path to flat abs and trim thighs: Enviga, the first drink to boast not low, not zero, but negative calories.
But if dieters think guzzling can after can of Enviga will allow them to nibble on leftover holiday cookies and skip the gym for one last session in front of the Yule log, they may be stuck in their 2006 bodies well into 2007. Doctors call Enviga little more than hype in a can and fuel for fantasies about weight loss.
The makers of Enviga bill the sparkling, caffeinated green tea as an energy drink designed to promote a healthy lifestyle. According to tests conducted by Switzerland's University of Lausanne and Nestle, who manufacture the beverage along with Coca-Cola, drinking three 12-ounce cans of Enviga per day burns 50 to 100 calories.
Though it's only available in New York City and Philadelphia now, early this year, the drink will hit store shelves nationwide.
Enviga gets its calorie-burning power from the combination of caffeine and EGCG, an antioxidant naturally found in green tea. Though its makers stand by the drink's ability to burn calories, Nestle and Coca-Cola claim they're not marketing Enviga as a weight loss product.
"This product seems ideal for folks that are exercising regularly, have a balanced diet, and are taking care of themselves. This is one more step. It would be great if the product was inspirational, but it's not a weight loss product," Coca-Cola spokesman Ray Crockett said.
Though Enviga is not marketed specifically as a weight loss product, some doctors and consumer advocates say that looking at the ads, it's hard to think of anything else.
Bright, splashy pictures of the drink in its three incarnations -- green tea, peach and berry -- along with cryptic catch phrases like "less than nothing, better than anything" evoke the magic elixir from Alice in Wonderland.
But according to doctors, drinking the green tea concoction is unlikely to make anyone shrink in size. For that reason, earlier this month the Center for Science in the Public Interest announced it will sue Coca-Cola and Nestle if they persist with the current ad campaign for Enviga.
"This is all marketing hype based on small measured increases in metabolism from green tea. When tested on patients, green tea does not produce measurable weight loss, probably because if it boosts your metabolism you eat more to compensate," said Dr. Darwin Deen of Albert Einstein College of Medicine's department of family medicine and community health.
Dr. David Katz, ABC News medical contributor and associate professor at Yale University's School of Public Health, said Enviga's calorie burning claims are based on insufficient research.
"It's putting marketing hype ahead of science," Katz said. "The science here is not ready for primetime. There is a hint in animal research and in very early studies that EGCG can boost metabolism a little bit, but we don't know if that contributes to weight control."