Ultra-Processed People: The Science Behind Food That Isn't Food

Van Tulleken examines the origins of the UPF concept. It stems from the work of Carlos Monteiro, a Brazilian nutritionist and statistician, who aimed to explain the explosion of obesity rates in Brazil from the mid-1980s onward. Studying the diets of thousands of Brazilians, Monteiro found that the problem lay not in any changes in recommended macronutrients, such as sugar or fat. Rather, the problem lay in a shift from traditional to non-traditional diets. He found that obesity was associated with new diets involving large amounts of new and highly processed foods like soft drinks, cereals, and cookies.

In 2010, Monteiro outlined a new way of defining food to understand and track the effects of these new processed foods. This was called the NOVA system. It breaks down food into four groups based on the nature and extent of its processing. NOVA group 1 includes food found in nature, such as fruit, meat, and vegetables. In group 2 are “processed culinary ingredients” like oil, lard, butter, and salt, basic ingredients that require some non-industrial processing (32). In group 3 are combinations of groups 1 and 2, foods processed largely for preservation. These include smoked or cured meats and fish, jams, and freshly made bread. In group 4 are ultra-processed foods. As Monteiro’s definition states, these are “formulations of ingredients, mostly of industrial use, made by a series of industrial processes requiring sophisticated technology and equipment” (33). These processes often involve the breaking down of whole foods into substances, which are then subject to chemical modification. In short, NOVA group 4 foods are foods that are possible only through advanced industrial technology and within a complex, multifaceted industry of food production.

Van Tulleken discusses how Kevin Hall, a British scientist and nutritionist, devised a 2019 experiment to test Monteiro’s hypothesis that UPF causes obesity. Hall, as Van Tulleken explains, was skeptical about the idea at first, questioning what exactly it could be about processing that causes weight gain. Hall set up an experiment to disprove Monteiro involving 20 men and women. Half of the participants ate an 80% UPF, NOVA group 4 diet for two weeks, while the other half ate a diet containing no NOVA group 4 foods at all. They then swapped so that the first group had the non-UPF diet and the second group had the UPF diet for a further two weeks. Critically, each diet contained the same amount of salt, sugar, fat, and fiber, and each participant was allowed to each as much as they liked of their diet.

After a month, the results showed that those on the UPF diet had eaten an extra 500 calories per day and had gained weight accordingly. In contrast, those on the non-UPF diet lost weight. Thus, Hall demonstrated that UPF causes weight gain. Indeed, van Tulleken suggests, the study probably underestimates the effects of UPF on weight. The study did not consider how the packaging, marketing, convenience, and lower cost associated with UPF, which were not factors in the study, drive excess consumption of UPF in the real world. Nonetheless, Hall’s findings gave respectability to the UPF classification of food and Monteiro’s hypothesis linking it to ill health. Since 2019, more real-world studies have corroborated Hall’s findings. These include one study of 100,000 people in the British Medical Journal, which showed that a 10% increase in consumption of UPF was associated with a 10% increase in risk of cancer.

Van Tulleken retells the story of the first synthetic fat and discusses what this says about the origins and nature of UPF. As he explains, in 1912, Germany was looking for a way to end reliance on foreign oil for its war industry when two German scientists, Fischer and Tropsch, devised a way to get liquid fuel from low-quality coal, lignite, which Germany had in abundance. By the late 1930s, this process had been perfected, with 600,000 tons of fuel derived from lignite every year, leaving behind vast quantities of a waste product called “slackwax.”

However, Germany was also short of edible fat, which it wanted as part of its policy of autarky, or self-sufficiency. This policy aimed to mitigate the effects of a possible blockade as had occurred in World War I. As such, a German businessman, Imhausen, partnered with a well-connected politician, Keppler, to help convert slack wax into edible fat in 1938. They did this by adding glycerin to slackwax to make edible fat, speisefett. They then combined speisefett with a chemical called diacetyl to give the speisefett the superficial taste of butter. Thus, Imhausen and Keppler created “coal butter” and “the first totally synthetic food” (71). This synthetic butter was used by German troops in World War II, although it was later found, in secret documents recovered by the Allies after the war, that it caused severe kidney problems in the animals on which it had been tested.