Researchers have been studying the health effects of “ultra-processed foods” for over 15 years, yet doctors, food scientists, nutritionists and U.S. policy experts still haven’t agreed on a single definition for the term.
Not that the U.S. isn’t trying. In a Feb. 27 interview with podcaster Joe Rogan, Health and Human Services Secretary Robert F. Kennedy Jr. said the U.S. has a definition on the way.
“By April, we will have a federal definition of ultra-processed foods — first time in history,” he said.
We don’t know what the nation’s health leaders will adopt, but the strongest contender for a definition comes from Brazil, where restrictions on ultra-processed foods are already making their way into government regulations.
The term “ultra-processed foods” may conjure thoughts of certain junk foods: potato chips, sugary cereals, candies, sodas. But it includes a lot more groceries than you think.
That’s because the category isn’t based on how healthy or nutritious a food is, but rather how it is made. Some whole wheat breads, store-bought hummus and flavored yogurts could all be ultra-processed by some definitions.
It only takes one ingredient to make something “ultra-processed.”
Kennedy said once the U.S. establishes a definition, front-of-package food labels could provide more consumer guidance. “So every food in your grocery store will have a label on it. It’ll have maybe a green light, a red light or yellow light telling you whether or not it’s going to be good for you,” he said.
Here’s a glimpse at how defining “ultra-processed” played out in Brazil, why Kennedy’s regulatory vision may be a challenge, and why experts still can’t agree on whether regulating “ultra-processed” foods is the right approach.
Brazil’s system sorts food into four groups, including ultra-processed
In 2009, University of São Paulo researchers arrived at what would become the most popular food processing classification system used in health research — and introduced the term “ultra-processed,” into the mainstream.
The Brazilian “Nova” system divides food into four groups according to the “extent and purpose of industrial processing.” The technical definitions are complicated, but here’s the gist:
Group 1 foods are “unprocessed” or “minimally processed,” meaning they are straight from nature (fresh fruits, veggies, meats, dairy and eggs, oats, etc.), or slightly changed to make them safer or last longer (freezing, drying, pasteurizing, grinding, etc.).
Group 2 foods are “processed culinary ingredients,” things like butter, olive oil, honey, sugar, and salt that you’d have in your kitchen.
Group 3 foods are “processed.” It’s what you get when you combine the first two groups — salted nuts, cured meats, sugared fruits, canned veggies, pickles — or use fermentation, so fresh breads and cheeses count.
Group 4 foods are “ultra-processed,” defined as “formulations of ingredients, mostly of exclusive industrial use, that result from a series of industrial processes … many requiring sophisticated equipment and technology.” This group includes sodas, packaged snacks, candies, mass-produced breads, cereals, fruit yogurts, chicken nuggets and hot dogs.
If you can make it in your kitchen, it’s likely one of the first three groups. If you’d need a factory and a chemistry degree, it’s probably Group 4, or “ultra-processed.”
When trying to identify Group 4 foods, the Brazilian researchers advise looking for at least one ingredient that is “never or rarely used in kitchens” or “classes of additives designed to make the final product more palatable or appealing,” such as flavors, colors, emulsifiers, sweeteners, thickeners, carbonation or glazing agents.
Until recently, most countries, largely in Latin America, that have introduced regulations around unhealthy foods have focused on nutritional content — taxing, labeling, or restricting the marketing of foods high in fats, sugars, or sodium.
But Brazil has taken a new step.
In 2014, Brazil incorporated the Nova definitions in its national dietary guidelines and advised Brazilians to avoid ultra-processed foods. In 2020, Brazilian school regulators limited spending on processed or ultraprocessed foods for the nation’s school meal program to 20%. By 2026, it dropped to 10%.
Regulations also prohibit any money from being spent on certain ultra-processed products including soft drinks, cereals or cereal bars with additives or sweeteners, mayonnaise, cakes, candies and cookies.
Prior to the 2020 ultra-processed food policy, around 40% of Brazilian municipalities were already spending below 20% of funds on ultra-processed foods.
A few Latin American countries have started to follow Brazil’s lead — regulating food not just based on nutrition but on the extent of processing. Mexico and Argentina have expanded package warning labels to include specific non-sugar sweeteners and caffeine, and in 2023, Colombia introduced a tax on ultra-processed foods that were also nutritionally poor.
Defining is one thing, regulating is another
Can a classification like Nova really be translated into American policy? Experts said that would be a challenge.
“Research definitions (like Nova) were designed to classify foods for epidemiological studies, not to create legally enforceable, product-by-product regulatory boundaries,” said Kantha Shelke, a food scientist and Johns Hopkins University senior lecturer.
The definitions in Brazil’s Nova groups are descriptive, and when tested, even food experts disagree on which foods belong in which category.
Since food manufacturers aren’t required to publicly disclose how food is made, ultra-processed foods typically have to be identified by the ingredients listed on the packaging — colors, flavorings, other additives — that are considered “markers of processing.”
This is an imperfect system. Not all “processing” is reflected on the ingredient label (extrusion cooking, for example), and the purpose of an additive — whether it is used as a preservative or thickener — can change whether a food is considered “ultra-processed.”
“Just the fact that there might be rare exceptions to the rule makes the Nova system and the definition of ultra-processed food, not surprisingly, a hot topic in policymaking,” said Maria Gombi Vaca, an assistant professor at the University of Connecticut’s Center for Food Policy and Health.
Barry Popkin, a University of North Carolina, Chapel Hill, nutrition professor, said regulations would not be that difficult, specifically if regulators didn’t go after all ultra-processed ingredients, just the color and flavor additives that are legally tracked by the U.S. Food and Drug Administration. That would capture most ultra-processed foods on the market, he said.
Several experts said new U.S. regulations would be subject to fierce litigation from the food industry and should account how policies affect food access and affordability.
Is ‘processing’ how we should think about healthy eating?
Experts are still debating whether the focus on ultra-processed food is the path to healthier food or a red herring.
A growing body of research has established an association between ultra-processed food consumption and negative health effects, including obesity, heart disease, diabetes and cancer.
Most studies, however, are observational, a 2025 Lancet research paper noted, and don’t necessarily prove that the processing of the food is the cause. Studies that measure causation have been short-term, lasting one to two weeks, and small, involving nine to 20 people.
Skeptics of the “processing-is-the-problem” camp warn that variables such as a person’s economic status, educational level, exercise habits and location can shape diet quality and health outcomes.
Experts disagree on what is making these foods so unhealthy. Are potato chips, for example, bad for you because of what’s in them or because of how they are made?
Popkin said processing itself matters. By breaking down the food before it gets to our bodies, “we digest it really quickly, and we’re hungry really quickly.”
Sugar from a glass of orange juice, for example, is absorbed much faster than a whole orange.
This is true for some food groups, notably fruit and carbohydrates, but not all, said Dr. David Ludwig, a Harvard University professor and pediatric endocrinologist. Fats and proteins are both digested more slowly, and processing them doesn’t really change how our body reacts. Eating a minimally processed steak is not much different than eating a hamburger patty.
Definitions of “ultra-processed foods” get the most heat for leaving nutrition out of the equation.
With a focus on processing, nutritionally rich foods such as whole grain breads, yogurts and plant-based meat alternatives can be categorized as “ultra-processed,” while foods that aren’t as healthy, but use sugar, salt, and butter, can skirt the label.
Marion Nestle, New York University professor of food, nutrition, and public health professor emerita, said there are “remarkably few” nutritious examples of ultra-processed foods. “The concept works pretty well in research and most people get it pretty easily.”
In the end, health experts said an awareness of both processing and nutritional content was important for a healthy diet.
PolitiFact Researcher Caryn Baird and Staff Writer Zoe Weyand contributed to this report.
Editor’s Note: Minimal use of Google Translate was used in the research of this story to translate websites and documents into English. We corroborated our understanding of translated documents with additional sources.
