One panel on sweeteners in schools was sponsored by the Corn Refiners Association, whose members produce high fructose corn syrup.

Inside the exhibition hall, Hershey's was handing out chocolate and strawberry milk and Butter Buds gave out fake butter crystals.

"These nutritionists and dietitians were here getting continuing education credits," says Butler. "So going to this conference and attending these sessions is something that they need to do to keep up their accreditation. These people work in all kinds of places. they work in school cafeterias, hospital cafeteria, they work in corporate settings — these are really the gatekeepers of our nutritional information."

The problem with such a heavy industry presence, according to Butler, is that "they are getting their information from a very one-sided panel that is sponsored by manufacturers of high-fructose corn syrup, which we know contributes to the obesity epidemic."

Butler says some of the attendees were troubled by the heavy industry presence at the meeting. "There were a lot of eye rolls at the McDonald's lunch," she says.

One veteran nutritionist told her: "I can't believe we're sleeping with the enemy."

One group of dietitians within the professional organization, Dietitians for Professional Integrity, wants to change the sponsorship policy but have been unable to get much traction. And Butler says sponsorships are still going strong.

She notes a study by Michelle Simon, a public interest lawyer and blogger, of corporate sponsorships of nutritionists' conference. Simon found that in 2001, the Academy of Nutrition and Dietetics listed 10 sponsors, and by 2011 there were 38, including Coca-Cola, PepsiCo, Nestle, Mars and others.

Copyright 2014 NPR.

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