The American Society for Nutrition published a paper last week stating that processed foods make up a vital part of the American diet, drawing the ire of some prominent nutritionists, who criticized the paper and accused its authors of conflicts of interest.
The paper, published in the American Journal of Clinical Nutrition, said that beyond being vital to the American diet, processed foods contribute to the health of the U.S. population, and it gave recommendations for making processed foods more nutritious and for improving the public’s perception of them.
But some nutritionists have shot back, saying the paper relies on an overly broad definition of processed foods. It included in its analysis foods that aren't generally thought of as processed, like packaged fruits and vegetables and roasted nuts. By including them, the critics say, the paper distorts the fact that more heavily processed foods, like children’s breakfast cereal, are far less nutritious.
"They pile all the different types of processing into one big grab bag," said Dr. Robert Lustig, a professor and obesity expert at the University of California, San Francisco. "Anything from washing lettuce leaves to creating new food out of lab ingredients that sit on a shelf."
Dr. Connie Weaver of Purdue University, the paper’s lead author, said its purpose was not to distort, but rather to spark an overdue conversation among nutritionists about what does and doesn’t constitute processed food, since existing definitions are vague.
"We’re calling for all the stakeholders to get together and help create a consensus," she said.
Weaver said settling on definitions will aid efforts to make processed foods more nutritious. That’s important, she said, because processed foods have become mainstays in the American diet, and aren’t going away.
But some experts believe focusing on delivering better nutrition through processed foods is a mistake. While processed foods are a significant part of Americans’ diet, "to say that getting nutrients from processed foods is a good thing and should continue ignores the fact that we could be getting those same nutrients from less processed foods and deriving far better nutrition overall," said Dr. David Katz, a nutrition expert and director of the Prevention Research Center at Yale University.
Some critics suspect another force is at play in the paper’s effort to improve the image of processed food. Weaver and several of her co-authors are either advisers to, have received funding from or own stock in major food industry players, including Nestle, Con Agra, and Hershey.
Katz said those conflicts of interest cast doubt on the paper’s assertions.
"The concern here is that this may be more about defense of the status quo than addressing fundamental problems with the American food supply and the typical American diet," he said.
Weaver said the authors’ relationships with the food industry did not influence the content of the paper. She said the committee of authors was convened by the American Society for Nutrition, not food companies.
The dispute touched off by the paper reflects the ongoing debate among nutritionists about the role their profession should play in guiding the future of the American food system and Americans' eating habits.
On one side are nutritionists like Katz and Lustig, who believe the focus should be on promoting fresh foods, encouraging changes in consumer attitudes and in the nation’s industrial food systems, which they say are largely responsible for growing incidences of diabetes and other chronic diseases.
On the other side are nutritionists like Weaver, promoting advances and refinements in food processing techniques, based on the idea that what’s important is food’s nutrient content, not whether it’s fresh.
"Processing is just not that relevant to the nutrient contribution," Weaver said, "which is the bottom line of this paper."