A sweeping statewide study released today points to soda and other sugar-sweetened beverages as one of the main reasons why we are fat.

"For the first time, we have strong scientific evidence that soda is one of the – if not the largest – contributors to the obesity epidemic," Dr. Harold Goldstein, executive director of the California Center for Public Health Advocacy, said Wednesday.

Obesity costs California $41 billion a year, an earlier report from the same organization found.

Suspicion of a link between soda and obesity isn't fresh news, but authors said the study is unprecedented in its scope.

"Bubbling Over: Soda Consumption and Its Link to Obesity in California" – a joint effort by the California Center for Public Health Advocacy and the UCLA Center for Health Policy Research – interviewed 42,000 Californians of all ages.

The study found that 24 percent of adults drink one or more non-diet sodas a day, and these adults are 27 percent more likely to be overweight.

The results for children were worse, researchers said. Sixty-two percent of adolescents ages 12 to 17 and 41 percent of children ages 2 to 11 imbibe at least one sugar-sweetened drink a day.

These kids, Goldstein said, will end up costing the state in future health care bills.

"This could be the first generation in modern history that will have a shorter life expectancy than their parents," he said.

The main culprit in soft drinks is sugar – lots of it. Soda racks up 17 teaspoons of sugar and about 250 calories per 20-ounce serving, and many add caffeine.

"A bottle of soda is nothing more than a sugar delivery device," said Goldstein. "We have a lot of very sweet kids."

He says the key to fixing the obesity epidemic is eliminating soda consumption, because many soft drinks are high-calorie and do little to curb hunger.

"When you eat food, it makes you full," said Judith Stern, a professor at the University of California, Davis' nutrition department. "When you drink a soda, it doesn't make you feel full, so it's wasted calories."

American soda consumption has been steadily rising: Compared with 30 years ago, we consume an average 278 more calories per day, almost half of it from soda, according to the California Center for Public Health Advocacy.

In the mid-1990s, children's intake of sugared beverages surpassed milk. And for each glass of soda consumed per day, a child's likelihood of becoming obese increases 60 percent.

Beverage makers say soda is unfairly demonized. In promoting healthy lifestyles, some soda companies – including Coca-Cola and PepsiCo – have introduced vitamin- enhanced zero-calorie sodas in the past several years, marketed as "sparkling beverages."

"The fact remains you can be a healthy person and enjoy a soft drink," Dr. Maureen Storey, an American Beverage Association spokeswoman, wrote in a statement.

Experts on childhood obesity say a sweet tooth for soda develops early in life.

"I have seen a number of children who come into the doctor's office with soda in their baby bottle," said Dr. Ulfat Shaikh, a pediatrician who works at UC Davis Children Hospital's weight management clinic. "That, frankly, is frightening."

Some parents say banning soda from the start is the only way to go.

Debi Ravenscroft of Loomis has never allowed her 10-year-old daughter to drink soda, even though her husband, Bob, drinks six to eight sodas a day.

Because her daughter never started drinking soda, she doesn't crave it.

"If she is at her friend's house and they offer soda to her, she says, 'Can I have a water, please?' " Ravenscroft said.

Ravenscroft sees other positive effects of keeping soft drinks away from her daughter.

"I have seen other kids who are allowed to drink Pepsi, and I honestly believe that's the reason why they can't sit still," she said.

The study also rekindled talk of a "soda tax" among California policymakers.

California limits school sales of sodas, candy and other junk food. Sodas, unlike most other foods, are subject to sales tax.

A 1 cent tax per ounce of soda would generate $1.8 billion per year in California.

Six states – Arkansas, Missouri, Rhode Island, Tennessee, Virginia, and West Virginia – have soda taxes.

"It's time to revisit the soda tax debate, now that we have ever-more convincing evidence of its role in obesity," said state Sen. Alex Padilla, D-San Fernando Valley, who chairs a committee on obesity and diabetes.

On a weekday afternoon, middle-schoolers on the way home from California Middle School stopped by a Marie's Do-Nut Shop on Freeport Boulevard in Sacramento. Several purchased soft drinks.

"It's just so … sugary," said 13-year-old Duy Ngo, as he snapped open a can of 7-Up.

Call The Bee's Anna Tong, (916) 321-1045.