Under the guise of sweet charitable giving, soda makers are handing out millions to big name health organizations so that the groups stay quiet about health issues that threaten to slim down drink profits—not to mention Americans themselves—a new study suggests.

Between 2011 and 2015, Coca-Cola Company and PepsiCo sponsored 96 national health organizations, including the American Diabetes Association, the American Heart Association, and the American Society for Nutrition, researchers report in the American Journal of Preventative Medicine. Meanwhile, lobbyists for the beverage makers successfully campaigned against nearly 20 proposed state and federal regulations aimed at protecting public health, such as improvements to nutrition labeling and soda taxes.

The pop makers' efforts to defeat public health policies casts doubt on the sincerity of their charitable giving to health groups. But the sponsorships alone are concerning, according to the study authors, Daniel Aaron and Michael Siegel of Boston University. Earlier studies have found that “sponsorships of health organizations can have a nefarious impact on public health,” they wrote, noting the efforts of Big Tobacco decades ago. Sponsors may directly or indirectly—through feelings of indebtedness—get an organization to take on their interests. As such, the Federal Trade Commission considers sponsorships a marketing tool. All in all, Aaron and Siegel conclude that the soda sponsorships “are likely to serve marketing functions, such as to dampen health groups’ support of legislation that would reduce soda consumption and improve soda companies’ public image,” they wrote.

Though the authors don’t prove that the soda sponsorships have resulted in “nefarious” effects, there’s plenty of reasons to buy the argument. For instance, in 2010, the charity Save the Children stunned colleagues and health professionals by abruptly dropping support for a soda tax—a policy the organization had been fiercely supporting as part of a campaign to combat childhood obesity. The turnabout occurred after the organization received more than $5 million from Coca-Cola Company and PepsiCo, though the charity’s executives denied the connection.

Similarly, in 2012 and 2013, the NAACP, which runs a Coca-Cola-funded health program and has close ties to soda makers, firmly opposed Mayor Bloomberg’s soda portion size limit for New York City. The stance was in spite of the fact that African American’s in the city suffer higher than average rates of obesity.

Last year The New York Times uncovered financial links between Coca-Cola and the research group, Global Energy Balance Network, run out of the University of Colorado. The researchers willfully downplayed the role of sugary beverages in poor health and obesity and shifted focus to a need for more exercise. The group has since disbanded and Coca-Cola’s chief scientist stepped down following the revelation.

And just last month, researchers at the University of California, San Francisco dug up evidence that sugar industry executives wrote fat checks to Harvard researchers in the 1960s to downplay the role of sugar in heart disease. Instead the researchers placed the blame solely on excess saturated fat—a scheme that skewed health policy and dietary guidelines for decades.

Despite such highly publicized examples of industry's meddling in health campaigns and policy, the new study by Aaron and Siegel is the first to try to capture the extent of the problem. The researchers sifted through financial disclosures on scientific literature, websites, and news reports, plus a database that tracks lobbying spending. The researchers wrote that their tally of 96 health organizations sponsored is likely an underestimate, given the potential for undisclosed funding plus the fact that they only looked for national—not state or local—health organizations.

Still, they conclude, the results show an extensive relationship between soda makers and health organizations, which have a lot of sway on policies and laws. “It is recommended that organizations find alternative sources of revenue in order to stop indirectly and inadvertently increasing soda consumption and causing substantial harm to Americans,” they conclude.

In 2009, the average American consumed 46 gallons of soda, giving the US the highest per capita consumption rate of the sugary beverages of any country. Meanwhile, about 38 percent of US adults and 17 percent of children are obese. Recent research has estimated that sugary drinks were responsible for a fifth of American’s weight gain.

American Journal of Preventive Medicine, 2016. DOI: 10.1016/j.amepre.2016.08.010 (About DOIs).