The science and politics behind the panic over ultraprocessed foods

Ultraprocessed foods are industrially manufactured products made from ingredients rarely found in home kitchens and containing little to no whole foods. They are designed for mass production, long shelf life, and convenience, often using techniques like separating whole foods into substances, chemically altering ingredients, or adding cosmetic additives such as food dyes. Examples include sodas, deli meats, frozen dinners, and packaged snacks. The term ultraprocessing was coined in 2009 by Brazilian epidemiologist Carlos Monteiro as part of the NOVA classification system, which categorizes foods into four groups based on processing level: unprocessed or minimally processed foods (Category 1), processed culinary ingredients (Category 2), processed foods (Category 3), and ultraprocessed foods (Category 4). Unlike homemade versions of foods like cakes, industrially produced versions with additives are classified as ultraprocessed, even if their nutritional content is similar.

Food processing has existed for millions of years, beginning with cooking, the first form of food processing, dating back 2 million years. Over time, humans developed traditional methods like grinding, baking, fermenting, drying, and pressing. The industrial age, starting in the mid-18th century, introduced new processing techniques such as canning, pasteurization, and refrigeration. These innovations improved food safety, shelf life, and convenience, enabling the development of urbanized societies and global food supply chains. By the mid-20th century, food manufacturers added complex technologies to create standardized, mass-market foods. While these innovations brought benefits, public health experts warned about the rise of junk foods high in salt, sugar, and saturated fat, which are linked to obesity, diabetes, and other chronic diseases.

The NOVA framework, developed by Carlos Monteiro, classifies foods into four categories based on their level of processing. Category 1 includes unprocessed or minimally processed foods like fruits, vegetables, and raw nuts. Category 2 covers processed culinary ingredients such as oils, butter, and sugar, derived from Category 1 foods. Category 3 consists of processed foods made by combining Category 1 and 2 ingredients using traditional methods like baking or canning, including items like canned beans or fresh bread. Category 4, ultraprocessed foods, are industrially manufactured products designed to be convenient, hyperpalatable, and profitable. Examples include soft drinks, packaged snacks, and frozen meals. The framework emphasizes that ultraprocessed foods are often engineered to displace whole foods and are typically high in additives, preservatives, and artificial flavors.

Research has linked ultraprocessed food consumption to higher risks of chronic diseases and early death, with studies showing that people consuming more ultraprocessed foods tend to have worse health outcomes. However, the science is not definitive. Some ultraprocessed foods, like sodas and processed meats, are consistently associated with negative health effects such as heart disease and stroke. Others, like breads, cereals, and yogurt, show no clear links or even lower rates of these health problems. Only a few clinical trials have examined the direct health effects of ultraprocessed foods, and their results are mixed. One study found that participants eating ultraprocessed foods consumed more calories and gained weight compared to those eating minimally processed foods, but other experiments found no significant effects. These studies typically last only a few weeks, making it difficult to draw conclusions about long-term health impacts.

The definition of ultraprocessed foods is highly contested. Critics argue that the NOVA classification is ambiguous and subjective, as the same food can be classified differently based on whether it is homemade or industrially produced. For example, a homemade cake is a Category 3 processed food, but an industrially made cake with preservatives is a Category 4 ultraprocessed food, even if their nutritional profiles are identical. Many nutrition scientists are unconvinced that processing alone explains health risks, instead pointing to poor nutritional profiles and overeating as key factors. They also warn that demonizing ultraprocessed foods could create unnecessary fear, promote disordered eating, and stigmatize products like plant-based meats or baby formula. Additionally, ultraprocessed foods provide convenience and affordability for many families, making their complete rejection impractical for some.

Public health researchers and food policy advocates argue that the evidence linking ultraprocessed foods to health risks is strong enough to justify immediate policy action, such as regulating their production, marketing, and sale. They contend that ultraprocessed foods are a symptom of an unsustainable industrial food system dominated by a few corporations, which harms public health, food culture, business, and the environment. Advocates also note that many supporters of ultraprocessed foods have ties to the food industry, raising concerns about conflicts of interest. On the other hand, skeptics argue that the debate has become a moral panic and that the focus should remain on improving the nutritional quality of foods rather than banning ultraprocessing entirely. The key disagreement is whether policymaking should target ultraprocessing directly or focus on traditional nutrient-based dietary guidelines.