Ultraprocessed foods are now a regular part of American eating patterns, spanning sugary cereals, frozen meals, and snacks, according to Associated Press reporting. The AP also cited researchers’ estimates that most Americans eat ultraprocessed foods on any given day or even at a single meal, and that kids and teens consume a larger share than adults.
The question facing health researchers and policymakers is how bad those foods might be—and what can realistically be advised or regulated while science continues to refine how the risks should be interpreted. The experts interviewed by the Associated Press said much of the existing evidence links higher consumption to negative health outcomes, but they also cautioned that observational research usually cannot prove that ultraprocessing itself causes the problems.
When experts discuss “ultraprocessed foods,” they typically refer to a classification system developed by epidemiologist Carlos Monteiro and colleagues in 2009, which organizes foods according to how much they are processed rather than focusing only on nutrient content. Kevin Hall, a researcher at the National Institutes of Health who focuses on metabolism and diet, said that at the top of the four-tier scale are foods created through industrial processes and containing additives, colors, and preservatives that “couldn’t duplicate in a home kitchen.” Hall added that these foods are “most, but not all, of the packaged foods you see.”
Hall and other experts said processing alone does not automatically determine whether a food is healthy. Whole-grain bread, yogurt, tofu, and infant formula are examples of items that can involve substantial processing yet also deliver nutrition, underscoring that ultraprocessing is not the same as nutrient composition.
The Associated Press reported that higher intake of ultraprocessed foods, as a group, tends to come with higher levels of sodium, saturated fat, and sugar and lower levels of fiber and protein. Still, experts said it remains unclear whether those nutrients fully explain the observed health outcomes or whether other aspects tied to industrial processing play a role.
A key point in the debate is that some experiments try to move beyond correlation by testing similar diets in controlled settings. Hall and colleagues conducted an influential study published in 2019, the AP reported: 20 adults lived at a National Institutes of Health center for a month and ate two types of diets—ultraprocessed and unprocessed—matched for calories, sugar, fat, fiber, and macronutrients across two-week periods. The researchers found that when participants ate ultraprocessed foods, they consumed about 500 more calories per day than when they ate unprocessed foods, and they gained an average of about 2 pounds (1 kilogram) during the study period. When participants ate only unprocessed foods for the same amount of time, they lost about 2 pounds (1 kilogram).
Hall said more definitive research is still needed, including understanding the mechanisms that could connect ultraprocessed foods to deleterious health consequences. He also said a more detailed study is underway, but the process is “slow and costly,” with results not expected until late next year.
Policy questions have also entered the discussion. The Associated Press reported that advocates argue the strength and breadth of the research should be enough to spur government and industry changes even before scientists settle all the mechanisms. Neena Prasad, director of the Bloomberg Philanthropies’ Food Policy Program, called for actions such as increased taxes on sugary drinks, stricter sodium restrictions for manufacturers, and efforts to curb marketing of certain products to children, comparing those marketing efforts to tobacco restrictions. Prasad said, “Do we want to risk our kids getting sicker while we wait for this perfect evidence to emerge?”
The AP also reported that U.S. Food and Drug Administration Commissioner Robert Califf raised the subject earlier this year, telling a conference of food policy experts that ultraprocessed foods are “one of the most complex things I’ve ever dealt with,” and saying, “We’ve got to have the scientific basis and then we’ve got to follow through.”
For consumers trying to navigate what they can control at home, experts said it can be difficult to decide which products to target because ultraprocessed foods are so varied. Aviva Musicus, science director for the Center for Science in the Public Interest, which advocates for food policies, said, “The range of ultraprocessed foods is just so wide.” Instead, Musicus suggested focusing on ingredients and using labeling to choose options that match the current U.S. Dietary Guidelines, adding that “We have really good evidence that added sugar is not great for us” and that “We have evidence that high-sodium foods are not great for us.” She also pointed to evidence that “fruits and vegetables which are minimally processed are really good for us,” and she cautioned against vilifying particular foods, saying, “I think foods should be joyous and delicious and shouldn’t involve moral judgment.”
The Associated Press reporting also noted how widely available and convenient these products are, reflecting why even guidance aimed at reducing certain ingredients may run into practical limits for many households. In that context, experts’ differing views on regulation and consumer action appear less like a disagreement over whether health research matters, and more like a dispute about how soon to act while the science works through questions about mechanisms and causality.
The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Science and Educational Media Group. The AP is