The companies have been working in China since the the late 1990s at encouraging exercise, instead of eating healthier, to curb the country's growing obesity problem, Greenhalgh found. The New York Times first reported the findings.
The institute was founded by a Coke executive in Washington, D.C. four decades ago and now has 17 international branches, including one in China that is housed within the Chinese Center for Disease Control and Prevention, according to the research findings.
Those close government ties seem to be paying off. While Chinese public initiatives usually promote exercise, they rarely acknowledge the role of diet in losing weight and improving health.
"Presenting itself as an advocate of 'healthy active lifestyles,' Coke promoted the message that all foods and drinks are part of a healthy diet; to avoid obesity, what matters is how much you move," Greehalgh found. "And it maintained that there were health benefits to the ingredients of sugar sweetened carbonated beverages."
One government campaign cited in Greenhalgh's research called Happy 10 Minutes encourages children to exercise for 10 minutes every day — without mentioning cutting back on junk food or sugary drinks.
Coke spokeswoman Ann Moore said in a statement that company supports current recommendations by the World Health Organization and other health authorities to limit intake of added sugar.
"We recognize that too much sugar isn't good for anyone," Moore said, adding that the company has listened to prior criticism to understand its role in the fight against obesity.
She said Coke decided in 2017 to stopped providing 100 percent of the funding for any research related to well-being, either directly or through a trade group.
"We support research efforts by independent and respected research institutions and universities," she said. "Under our guidelines, we will provide financial support for such research only if a non-Coca-Cola entity funds at least 50 percent of the cost."
In a statement, the institute's spokeswoman Kristin DiNicolantonio said that the group does not lobby, conduct lobbying activities or make policy recommendations.
"Because of its unique public-private structure, ILSI fills knowledge gaps and serves society in ways that any one entity on its own cannot," spokeswoman Kristin DiNicolantonio said in a statement.
The institute's statement also noted that the group requires that at least three companies fund a project to avoid a single business dominating the agenda and that many experts named in Greenhalgh's report are no longer employed or affiliated with the organization.
Pepsi, McDonald's and Nestle did not respond to requests for comment from CNBC.
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