WASHINGTON (The New York Times News Service) -- As Congress debated health care legislation last month, a new ad campaign was saturating the Washington media market. It featured two happy campers, a slim, white, adult couple on a budget holiday sipping small cans of soda, and objecting to "taxes on simple pleasures."

Welcome to the 21st century edition of the tobacco wars.

Funded by the beverage industry, Americans Against Food Taxes wants to halt what health-care researchers believe is one of the best weapons in the fight against obesity: a soda tax.

Sugary soft drinks of scant nutritional value are responsible for a whopping 43 percent of the increase in Americans' daily calorie intake since the late 1970s. Evidence suggests that the body digests liquid calories in a way that accelerates weight gain.

Soda serving sizes have ballooned from 8-ounce bottles to 20-ounce containers and 30-ounce refills; an average American now downs a gallon of soda a week.

"We've got at least half the smoking gun," said Harold Goldstein, executive director of the California Center for Public Health Advocacy.

Kelly Brownell, an obesity researcher at Yale University's Rudd Center for Food Policy and Obesity who urges a penny-per-ounce tax on sugary drinks, calls it "the single most effective approach we have."

Its effects would be swift and powerful, he said, cutting consumption 10 percent, reducing medical costs by $50 billion in a decade, and raising $150 billion.

A broader tax on so-called "junk foods" could raise $500 billion over ten years, said University of Virginia scholars Carolyn Engelhard and Arthur Garson and the Urban Institute's Stan Dorn, in a paper last month.

Taxing junk food is gaining a strong following among public health researchers alarmed at the threat obesity poses to the nation's health and finances. Yes, such a tax would disproportionately affect the poor, they say, but the poor are disproportionately dying from obesity, and the revenue could be used to fight the epidemic in their neighborhoods.

Congress has shown little interest in junk food taxes despite a desperate search for money to fund health care reform. A sugared beverage tax was scuttled last year by Maine voters and died this year in New York.

In fact, Washington offers incentives to produce more salty snack foods and sugary beverages. Congress last year voted to extend corn, sugar and other farm aid despite a consensus among public health experts that such subsidies play a key role in the obesity epidemic by making processed fats and sugars cheaper than healthy food.

Brownell accused the food industry of adopting tobacco-industry tactics to ward off government intervention: promoting personal responsibility, offering "healthier" versions of products with negligible health improvements, disclaiming responsibility for abuse of their products, and claiming that people should have free choice.

Industry officials dismiss such comparisons as do-gooder demagoguery.

"We reject the notion of any connection between beverages and tobacco," said Judith Thorman, senior vice president for government affairs for the American Beverage Association.

Food and beverage companies' marketing budgets match in just four days the $100 million a year that the Robert Wood Johnson Foundation is spending to promote healthier eating, Brownell argued.

"Marketing is just washing over this country like a tidal wave," he said, "and we're trying to give people swimming lessons."

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