For decades, the United States Department of Agriculture has played a central role in shaping what Americans eat. But according to Dr. Dariush Mozaffarian, a cardiologist and director of the Food is Medicine Institute at Tufts University that role has come with a fundamental problem built into its design.
“USDA has a conflicted mandate,” Mozaffarian explained. “They’re supposed to put out the guidelines, but their major purpose is to support the US food sector. That’s what the USDA is supposed to do.”
The result he argues, has been a pattern of selective guidance spanning generations. When the scientific advisors behind the dietary guidelines recommended that Americans eat more of certain foods, fruits, vegetables, and nuts, the USDA embraced those messages readily.
But when those same scientists urged reductions in refined grains, processed foods, sugar-sweetened beverages, and processed meats, the recommendations were quietly set aside.
“Anytime the scientists who advise them have said, ‘Hey, we need to be eating fewer refined grains or less processed foods or less sugar-sweetened beverages or less processed meats,’ the guidelines have quietly buried that or eliminated or ignored it,” Mozaffarian said.
Instead of naming specific foods to avoid, prior guidelines redirected public attention toward nutrient targets, telling Americans they could eat whatever they wanted as long as they stayed within limits for fat, sugar, or other individual nutrients. This framing, Mozaffarian contends, produced a deeply misleading message.
“They’ve kind of hidden the focus on food as nutrient targets. And this has led to the incorrect message that there are no bad foods. All foods are okay. You can be indulgent as long as you’re eating a balanced diet. There are clearly bad foods and there are clearly good foods.”
He points to the 2025 dietary guidelines as a meaningful departure from this history. For the first time, the guidelines explicitly tell Americans to eat real food and to avoid packaged foods, processed foods, ready-to-eat foods, sugar-sweetened beverages, candy, cookies, and products containing artificial sweeteners, colors, and preservatives. When taken together, Mozaffarian estimates that guidance covers roughly 50 to 60 percent of the current food supply.
“That’s a big shot across the bow of the food industry,” he said.
Underpinning these concerns is the broader issue of food additives and regulatory oversight. Under a provision known as the GRAS loophole, originally created to allow commonly recognized safe ingredients like ginger or turmeric into food without formal FDA review, companies have been permitted to self-certify the safety of new additives, keep their findings private, and add compounds to the food supply without any public notification.
“99% of food additives do not get reviewed by the FDA,” Mozaffarian said. “They not only don’t get reviewed, FDA doesn’t even know they exist.”
He noted that the United States stands alone among developed nations in permitting this exception, with every other country requiring independent review of food additives before they reach consumers.
Today, approximately 60 percent of calories in the American food supply come from ultraprocessed foods, a figure Mozaffarian describes as the product of decades of compounding policy failures, tobacco industry involvement in food manufacturing, and a regulatory system that has never been adequately funded to protect public nutrition. The FDA’s total budget sits at roughly $7 billion, with only about $15 million directed toward human nutrition work including labeling, additives, and public health guidance.
“We’re trying to fix the problem instead of trying to find the underlying cause of the problem,” host Rhonda Patrick put it plainly.
Whether the current administration will follow through on proposed reforms to close the GRAS loophole remains uncertain.
