Experts Grapple with Defining Ultra-Processed Foods Amid Public Health Concerns

The Debate Over Ultra-Processed Food Definitions

Public health experts largely acknowledge the American diet's negative impact on health. In recent years, ultra-processed foods, which constitute a significant portion of the American diet, have become a focal point for health improvement initiatives.

Recent developments include:

• Health Secretary Robert F. Kennedy Jr.'s statements linking these foods to a chronic disease epidemic.
• California's recent ban on specific ultra-processed foods in school lunches.
• The Trump administration's initiative to develop a federal definition for ultra-processed foods.
• A recent survey indicating that a majority of U.S. consumers are attempting to avoid these foods.

Despite public interest and policy efforts, a consistent definition of ultra-processed foods remains a challenge among public health and nutrition experts.

Understanding Ultra-Processed Foods

The term "ultra-processed food" originated from Brazilian researchers who developed the NOVA classification system based on food processing levels. This system categorizes foods ranging from:

• Unprocessed or minimally processed foods: Examples include an apple or frozen peas.
• Ultra-processed foods: These are characterized by being made from manufactured ingredients and containing additives such as artificial colors, flavors, emulsifiers, and preservatives. Examples include processed deli meats, packaged cookies, candies, sweetened beverages, and frozen ready meals.

Dr. Dariush Mozaffarian, head of the Food is Medicine Institute at Tufts University, states that ultra-processed foods involve "additives and processing methods that aren't used in home cooking." He cites nearly 100 observational studies and three randomized controlled trials linking overconsumption of ultra-processed foods to increased risks of Type 2 diabetes, obesity, cardiovascular disease, certain cancers, and depression.

Divergent Perspectives on Defining the Category

Not all experts agree on how to classify or address ultra-processed foods.

Arguments for Nuance

Julia Wolfson, an associate professor at the Johns Hopkins Bloomberg School of Public Health, notes that some foods fitting the ultra-processed definition may not be unhealthy. Examples include packaged whole-grain breads, plant-based milks, and some yogurts, which have been associated with health benefits in studies (e.g., yogurts with lower colorectal cancer risk, whole-grain breads with lower Type 2 diabetes and cardiovascular disease risk). She also points out that some ultra-processed items, like jarred pasta sauce, can offer convenience and cost savings for home cooking. Wolfson suggests that health policies should differentiate among ultra-processed foods rather than treating them uniformly.

Debate: Processing vs. Nutrients

The central point of contention revolves around whether policy should target processing methods or the nutritional content of foods.

Dr. David Ludwig, a professor of nutrition at the Harvard T.H. Chan School of Public Health, argues for focusing on the overall nutritional quality of foods rather than processing levels. He suggests the "ultra-processed" concept is too broad, potentially stigmatizing healthy foods or inadvertently promoting less healthy ones. He provides the example of a low-sugar, high-protein packaged cereal being considered ultra-processed, while plain cornflakes (minimally processed) could become unhealthy with added sugar at home. Ludwig also notes that while some additives (e.g., emulsifiers) may pose concerns, others (e.g., dietary fiber) are beneficial or benign. He advocates for targeting nutrients known to be harmful, such as added sugars and refined grains.

The Institute of Food Technologists (IFT) supports a similar approach, recommending a definition that prioritizes nutritional quality (e.g., high in salt, sugar, and fat) over the degree of processing.

Conversely, Dr. Mozaffarian of Tufts University contends that any definition overlooking processing's role misses a critical aspect. While ultra-processed foods often contain high levels of salt, sugar, and refined starches, he asserts that "there's something about the processing itself that's important." He explains that high processing alters the physical and chemical structure of foods, influencing digestion. This "molecularly disassembled and reassembled" nature, exemplified by products like cheese puffs, leads to rapid digestion and quick absorption of sugars and starches into the bloodstream. Over time, this rapid absorption can increase the risk of insulin resistance and Type 2 diabetes. Furthermore, rapid digestion means fewer nutrients reach the lower intestine, potentially impacting the gut microbiome, which plays a role in metabolism and the immune system. Mozaffarian also points to evidence suggesting greater calorie absorption from ultra-processed foods compared to high-fiber whole foods. He concludes that sufficient evidence exists to warrant action, despite the need for further research on exact mechanisms.

Consumer Considerations

Wolfson advises consumers that ultra-processed foods remain prevalent and are often more affordable and accessible. She suggests policy changes are needed to make healthier options more attainable. In the interim, consumers can:

• Choose whole-grain options for packaged breads.
• Reduce consumption of sugary and artificially sweetened beverages and processed meats, which are strongly linked to health concerns.
• Read ingredient lists, aiming for products with fewer unfamiliar ingredients.

She acknowledges that finding non-ultra-processed options is not always feasible, and it involves a "tradeoff" between nutrition and processing. Prioritizing whole foods like beans, frozen fruits, and vegetables, which are often affordable, is also recommended.

Mozaffarian highlights the difficulty for average consumers given expert disagreement, underscoring the necessity for federal policy guidance.