Taxing sugary drinks could help fight obesity, two U.S. authors say. More than 300 million adults worldwide are obese, the World Health Organization has estimated.

Adding a special tax on sugared drinks like soda pop could significantly cut consumption and help reduce levels of obesity among both adults and children, say the authors of an opinion article in the New England Journal of Medicine.

The authors, Kelly Brownell of Yale University and New York City Health Commissioner Dr. Thomas Frieden, say imposing a tax of one cent-per-ounce (28 millilitres) on sugar-containing drinks could reduce consumption of the products by more than 10 per cent.

"What we're hoping for is a penny-per-ounce tax on all beverages where sugar is added," Brownell, director of the Rudd Center for Food Policy and Obesity, said Wednesday from New Haven, Conn.

"So that would include traditional soft drinks that we all know about, but also sugar-added teas, energy drinks and sports drinks. It would also include fruit-flavoured drinks."

He said children and teens are heavily targeted by — and particularly vulnerable to — the promotion of sugared beverages like name-brand pops and energy drinks on television, in films and on websites.

"It trains them to believe that sweetened drinks are good, that they're glamorous, in some cases that they're sexy, they're athletic and most of all they're cool," Brownell said. "Children have a tough time, especially at younger ages, distinguishing the commercial intent from marketing and the programming the marketing is embedded in."

Sugary drinks can add pounds 

In fact, beverages now account for 10 to 15 per cent of calories consumed by children and adolescents, the authors write, noting that a 2001 study found that each extra can or glass of sugared beverage downed each day increases a child's risk of obesity by 60 per cent.

Dr. Arya Sharma, an obesity expert at the University of Alberta, said there is a lot of evidence suggesting that over-consumption of sugary drinks can pile up excess calories. Limiting intake would "help reduce the caloric burden of the population" — as long as people don't compensate by increasing calories from other foods, he cautioned.

"I've seen patients who consume up to two litres (of sugared drinks) a day," Sharma said. "There are patients out there who appear to be drinking a lot of calories from sweetened beverages, and when they stop drinking those beverages, you actually do see quite impressive weight loss."

Don't target pop, industry says

But Susan Neely, president and CEO of the American Beverage Association, contends that taxing sweetened drinks would have no effect on reducing obesity — it would only financially harm families because of higher grocery costs.

"We agree that obesity is a serious and complex problem," Neely said in a statement. "It defies both science and common sense, however, to think singling out one product as a unique contributor to obesity will make a dent in the problem."

Brownell said sugar-laden drinks have been linked by scientific research to a number of health problems, including obesity, diabetes and even heart disease.

"Now that doesn't mean that sugared beverages are the only contributor to these problems …and it also doesn't suggest that by changing sugared beverage problems that you would wipe those medical complications away."

"But it's a very logical place to start."

Brownell said tax revenues on pops and other sweetened drinks could be used for obesity prevention, including paying for facilities and programs for physical activity and subsidizing healthy foods like fruits and vegetables to lower their cost to consumers.

"Nobody claims that sugared beverages are essential for survival," he said. "And if people switch from that to other beverages, they can do so quite readily. Their health would improve and we would have lower health-care costs."

Reward good behaviour

Dr. David Jenkins of the University of Toronto, who holds a Canada Research chair in metabolism and nutrition, doesn't believe that picking one food type for extra taxation is the way to go in the battle over the population's bulge.

"The temptation is to aim your guns on one target and then you miss the rest of the fleet," he said. "I would like to think we are more rounded in our taxation."

Jenkins said instead of trying to solve the growing obesity epidemic with punitive legislative actions like taxation, a better idea would be to use rewards, such as making gym memberships and exercise programs tax-deductible.