Coca-Cola has poured millions into funding research that suggests exercise, not diet, is the best way to fight obesity, but public health critics call it a flawed message.

On the website for the Global Energy Balance Network, the network's vice-president Steven Blair talks about what he says are mistaken assumptions about the cause of obesity.

"They're eating too much, blaming fast food, blaming sugary drinks and so on, and there's virtually no compelling evidence that that, in fact is the cause," Blair says in the video.

The network is funded by Coca-Cola. The source of funding wasn't disclosed on the website until Ottawa-based obesity expert Dr. Yoni Freedhoff started asking questions.

Freedhoff, who writes a daily blog, said he contacted a journalist at the New York Times because he felt it was an important story.

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Coca-Cola didn't disclose it funds the Global Energy Balance Network until a Canadian obesity expert asked questions about funding. (David Goldman/Associated Press)

"For me the words energy balance is a red flag in the context of obesity," Freedhoff said Monday. "The fact of the matter is it's not a fair balance and we can't outrun our forks very efficiently."

Freedhoff said the scientific consensus is that energy input matters far more than energy output when it comes to weight. At best, exercise slows down weight gain.

Two years ago, Coke sponsored ads with a pro-exercise message. At the time, Freedhoff called the campaign Coke's way to try to avoid legislation such as soda taxes and cup size limits that would affect their sales.

Flawed message

"Providing this message that you can balance your input and your output, it's a flawed message," Freedhoff said.

He is critical of industries funding science.

"I do think that these partnerships are not going to be looked upon kindly by history. Just like we do now with tobacco, we look back and see how tightly intertwined tobacco was with research, with public health, with charity, with the arts, we think 'how did we let them do that?'"

Marion Nestle is a visiting professor at Cornell University in Ithaca, N.Y., and author of the book Soda Politics: Taking on Big Soda (And Winning).

"If you want to lose weight, there's nothing that works better than eating less," Nestle said. She suggests people start by cutting out sugary drinks, since sodas are sugar and water with no redeeming nutritional value.

Coca-Cola has given millions to produce studies published in respectable nutrition journals saying exercise is more important than what you eat. Nestle advises people to take that information with a "grain of sugar."

Smoke screen

Dr. Miguel Martinez-Gonzalez of the department of preventive medicine and public health at the University of Navarra in Pamplona, Spain, has studied financial conflicts of interest in obesity research funded by the sugar-sweetened beverage industry.

Martinez-Gonzalez and his colleagues found that 83 per cent of scientists funded by industry could find no relationship between obesity and soft drink consumption. But 83 per cent of independent researchers did. He says it adds up to a pernicious effect on scientific publications.

"They want to send a smoke screen on the real fact that they are doing harm with products," Martinez-Gonalez said. "The way of reducing the harms that these scientific findings can do to the business of the food industry is to cast doubt on the scientific strengths of the published research."

In an emailed statement, Coca-Cola said it has a long history of supporting scientific research.

"We make every effort to ensure we are providing support in an appropriate manner and in accordance to the standards set forth by the universities and organizations with which we work. It's important to us that the researchers we work with share their own views and scientific findings, regardless of the outcome, and are transparent and open about our funding," the Coca-Cola Company said.

With files from CBC's Kelly Crowe