What food scientists really think of the ultra-processed foods panic

Dr. Matt Teegarden likes to compare apples to apples. Or, at the very least, he wants studies on ultra-processed foods to compare apples to applesauce—not just apples to orange juice. That distinction, he argued in a Wednesday seminar hosted by the Institute of Food Technologists, is crucial in parsing the nutritional complexity of modern food processing. As it stands, many of the most-cited studies on the topic conflate categories in ways that obscure rather than illuminate the role of processing in nutrition.

The conversation around ultra-processed foods (UPFs) has accelerated in recent years, with public health advocates and consumers alike turning to the NOVA classification system to decode the complexities of modern food production. But Teegarden, a food scientist and chemist, alongside Dr. Susanne Bügel, a professor at the University of Copenhagen, suggests that the system is oversimplified, failing to account for the nuances of nutrition, formulation and processing methods.

The NOVA system —  which was developed in the early 2000s by researchers at the University of São Paulo, led by Brazilian nutritionist Carlos Monteiro — classifies foods into four categories: unprocessed or minimally processed foods, like fresh fruit and vegetables; processed culinary ingredients, like oils and sugars; processed foods, such as canned vegetables or tinned fish; and ultra-processed foods, which include packaged snacks, sodas and flavored yogurts. The issue, Teegarden pointed out, is that the system treats vastly different foods as nutritionally equivalent simply because they undergo a similar level of processing. 

A loaf of whole wheat bread, for instance, can be classified as either a category 2 or a category 4 food, depending on the production method. The same goes for yogurt and canned beans.

“If beans are just canned in water and a little bit of salt, that would be group three,” Teerfarden said. “But if maybe they have EDTA [ethylenediaminetetraacetic acid] added for color retention, that would be seen as a cosmetic additive, and they would be group four, even though they're virtually the same product.”

Bügel is leading an initiative aimed at refining this approach. Her team is working on a classification system that integrates processing methods with nutritional content, providing a more holistic view of a food’s health impact. She points out that foods like mass-produced packaged breads, breakfast cereals and fruit yogurts are classified as ultra-processed under the NOVA system, yet despite this classification, these products still offer significant nutritional value. 

“It’s very difficult to use [the NOVA system], both for the professionals and for the consumers,” she said. “For the professionals, we have to guess whether people are eating bread bought in a supermarket or bread bought in a bakery. It’s absolutely not based on scientific evidence.” 

The oversimplifications of the NOVA system become even more apparent when examining epidemiological studies linking UPFs to negative health outcomes. Many rely on dietary recall data, a notoriously unreliable metric, and don’t necessarily track food consumption with processing levels in mind. 

“Importantly with NOVA, the data that’s been collected in a lot of the studies that have been published thus far, the data is not necessarily collected with processing in mind,” Teergarden said. “In fact, a lot of the data was collected before NOVA was even invented. We have a lot of historical data here. So the processing levels of the foods in these dietary surveys are actually implied.” 

That imprecision, coupled with the broad category definitions, has led to some dubious findings. One study, Teegarden pointed out, found a correlation between UPF consumption and accidental death — a statistical oddity that likely indicates residual confounding rather than causation. “So be careful if you’re eating a candy bar and walking under an air conditioning unit,” he joked. 

Other studies, while more rigorous, still struggle with the challenge of isolating processing as an independent health factor.

In contrast, the gold standard for nutritional research is the randomized controlled trial, which allows scientists to isolate specific dietary variables. Only a handful of such studies exist on UPFs, but they do suggest that ultra-processed diets may encourage overeating. However, Teegarden argues that even these studies lack crucial nuance.

Take, for instance, a recent study conducted in Japan. On the first day, participants assigned to the ultra-processed diet were given fried chicken, biscuits and a giant bowl of sweetened yogurt. Meanwhile, the minimally processed diet featured rice, vegetables and lean protein. 

“My issue here as a food scientist is that we're not testing whether or not making something ultra-processed is causing these effects,” he said. “We're testing these overall dietary patterns. So we're missing the buck a little bit here because we've controlled for nutrient content, but we haven't controlled for food type.” 

The idea that all ultra-processed foods are inherently unhealthy ignores an inconvenient truth: Some UPFs contribute meaningfully to a balanced diet. Fortified cereals provide essential micronutrients, plant-based milks cater to those with dairy intolerances and some packaged breads offer whole grains that many people wouldn’t otherwise consume.

The goal, according to both Teegarden and Bügel, shouldn’t be to demonize processing as a concept, but rather to refine how we assess its impact on health. A smarter classification system — one that accounts for processing, formulation and nutrition — could help public health officials provide more accurate dietary guidance.

Until then, the conversation about ultra-processed foods remains muddied, shaped more by broad-strokes panic than by the scientific precision it deserves. And if we want to truly understand the role of processing in modern diets, we need to move beyond comparing apples to orange juice — and start comparing apples to applesauce.