In June, Dr. Barbara Bowman, a high-ranking official within the Centers for Disease Control and Prevention, unexpectedly departed the agency, two days after information came to light indicating that she had been communicating regularly with – and offering guidance to – a leading Coca-Cola advocate seeking to influence world health authorities on sugar and beverage policy matters.

Now, more emails suggest that another veteran CDC official has similarly close ties to the global soft drink giant. Michael Pratt, Senior Advisor for Global Health in the National Center for Chronic Disease Prevention and Health Promotion at the CDC, has a history of promoting and helping lead research funded by Coca-Cola. Pratt also works closely with the nonprofit corporate interest group set up by Coca-Cola called the International Life Sciences Institute (ILSI), emails obtained through Freedom of Information requests show.

Pratt did not respond to questions about his work, which includes a position as a professor at Emory University, a private research university in Atlanta that has received millions of dollars from the Coca-Cola Foundation and more than $100 million from famed longtime Coca-Cola leader Robert W. Woodruff and Woodruff’s brother George. Indeed, Coca-Cola’s financial support for Emory is so strong that the university states on its website that “it’s unofficially considered poor school spirit to drink other soda brands on campus.”

CDC spokeswoman Kathy Harben said Pratt had been on a “temporary assignment” to Emory University but his work at Emory “is completed and he is now back on staff at CDC.” Emory University websites still show Pratt as currently assigned as a professor there, however.

Regardless, research by consumer advocacy group U.S. Right to Know shows Pratt is another high-ranking CDC official with close ties to Coca-Cola. And experts in the nutrition arena said that because the mission of the CDC is protecting public health, it is problematic for agency officials to collaborate with a corporate interest that has a track record of downplaying the health risks of its products.

“These alignments are worrisome because they help provide legitimacy to industry-friendly spin,” said Andy Bellatti, a dietitian and founder of Dietitians for Professional Integrity.

One key message Coca-Cola has been pushing is “Energy Balance.”Consumption of sugar-laden foods and beverages is not to blame for obesity or other health problems; a lack of exercise is the primary culprit, the theory goes. “There is increasing concern about overweight and obesity worldwide, and while there are many factors involved, the fundamental cause in most cases is an imbalance between calories consumed and calories expended,” Coca-Cola states on its website.

“The soda industry is keen on deflecting the conversation away from the well-documented negative health effects of sugar-sweetened beverages and onto physical activity,” said Bellatti.

The messaging comes at a time when leading global health authorities are urging a crack-down on consumption of sugary food and beverages, and some cities are implementing added taxes on sodas to try to discourage consumption. Coca-Cola has been fighting back in part by providing funding for scientists and organizations who back up the company with research and academic presentations. Pratt’s work with the industry appears to fit into that messaging effort. Last year he co-authored a Latin America health and nutrition studyand related papers funded in part by Coca-Cola and ILSI to investigate the diets of individuals in Latin American countries and to establish a database for studying the “complex relationship existing between energy imbalance, obesity and associated chronic diseases…” Pratt also has been acting as a scientific “advisor” to ILSI North America, serving on an ILSI committee on “energy balance and active lifestyle.” And he is a member of the ILSI Research Foundation Board of Trustees. He also served as an advisor to an international study of childhood obesity funded by Coca-Cola.

ILSI’s North American branch, whose members include Coca-Cola, PepsiCo Inc., Dr Pepper Snapple Group and more than two dozen other food industry players, states as its mission the advancement of the “understanding and application of science related to the nutritional quality and safety of the food supply.” But some independent scientists and food industry activists consider ILSI to be a front group aimed at advancing the interests of the food industry. It was founded by Coca-Cola scientific and regulatory affairs leader Alex Malaspina in 1978. ILSI has had a long and checkered relationship with the World Health Organization, working at one time closely with its Food and Agricultural Organization (FAO) and with WHO’s International Agency for Research on Cancer and the International Programme on Chemical Safety.

But a report by a consultant to WHO found that ILSI was infiltrating WHO and FAO with scientists, money and research to garner favor for industry products and strategies. ILSI was also accused of attempting to undermine WHO tobacco control efforts on behalf of the tobacco industry.

One April 2012 email exchange obtained through a Freedom of Information request shows Pratt as part of a circle of professors communicating with Rhona Applebaum, then Coca-Cola’s chief scientific and regulatory officer, about difficulties getting cooperation on a study in Mexico from that country’s National Institute of Public Health. The Institute would not “play ball because of who was sponsoring the study,” according to an email Peter Katzmarzyk, a professor of exercise science at the Pennington Biomedical Research Center at Louisiana State University, sent to the group. Appelbaum defended the integrity of the research and expressed anger at the situation, writing “So if good scientists take $$$ from Coke – what? – they’re corrupted? Despite the fact they’re advancing public good?” In the email exchange Pratt offered to assist “especially if these issues continue to arise.”

Emails show Pratt’s communication with Applebaum, who also served a term as ILSI’s president, continued through at least 2014, including discussion of work for “Exercise is Medicine,” an initiative launched in 2007 by Coca-Cola and for which Pratt serves as an advisory board member.

Applebaum left the company in 2015 after the Global Energy Balance Network that she helped establish came under public scrutiny amid allegations that it was little more than a Coca-Cola propaganda group. Coca-Cola poured roughly $1.5 million into the establishment of the group, including a $1 million grant to the University of Colorado. But after Coca-Cola’s ties to the organization were made public in an article in The New York Times, and after several scientists and public health authorities accused the network of “peddling scientific nonsense,” the university returned the money to Coca-Cola. The network disbanded in late 2015 after emails surfaced that detailed Coca-Cola’s efforts to use the network to influence scientific research on sugary drinks.

Coca-Cola has been particularly zealous in recent years in working to counter concerns about consumption of beverages with high sugar content and links between sugary beverages and obesity and other diseases. The New York Times reported last year that Coke’s chief executive, Muhtar Kent, admitted that the company had spent almost $120 million since 2010 to pay for academic health research and for partnerships with major medical and community groups involved in curbing the obesity epidemic.

Marion Nestle, a professor of nutrition, food studies and public health at New York University and the author of “Soda Politics,” said that when CDC officials work so closely with industry, there is a conflict of interest risk the CDC should consider.

“Officials of public health agencies run the risk of cooptation, capture, or conflict of interest when they have close professional ties with companies whose job it is to sell food products, regardless of the effects of those products on health,” said Nestle.

Pratt’s ties to Coca-Cola and ILSI are similar to those seen with Bowman. Bowman, who directed the CDC’s Division for Heart Disease and Stroke Prevention, worked early in her career as a senior nutritionist for Coca-Cola and later while at the CDC co-authored an edition of a book called Present Knowledge in Nutrition as “a publication of the International Life Sciences Institute.“ The emails between Bowman and Malaspina showed ongoing communications regarding ILSI and beverage industry interests.

During Bowman’s tenure, in May 2013, ILSI and other organizers invited Bowman and the CDC to participate in a project ILSI was engaged in with the U.S. Department of Agriculture to develop a “branded foods database.” Travel costs for Bowman would be paid by ILSI, the invitation stated. Bowman did agree to participate and the CDC provided funding, at least $25,000, Harben confirmed, to support the database project. The 15-member steering committee for the project held six ILSI representatives, documents show.

Both Bowman and Pratt have worked under the direction of Ursula Bauer, director of the National Center for Chronic Disease Prevention and Health Promotion. After U.S. Right to Know publicized emails about Bowman’s ties to ILSI and Coca-Cola, Bauer defended the relationship in an email to her employees, saying “it’s not unusual for Barbara – or any of us- to correspond with others who have similar interests in our areas of work…”

Still, Bowman announced an unexpected retirement from CDC two days after the emails were made public. CDC initially denied she had departed the agency, but Harben said this week that was only because it took some time to “process” Bowman’s transition to retirement.

The relationships raise fundamental questions about how close is too close when public officials collaborate with industry interests that can conflict with public interests.

Yoni Freedhoff, MD, an assistant professor of family medicine at the University of Ottawa and founder of the Bariatric Medical Institute, said there is a real danger to when public health officials become too close with corporate players.