Ultraprocessed foods have become ubiquitous, filling grocery store aisles with items ranging from breakfast cereals and protein bars to flavored yogurt and frozen pizzas. Recent U.S. Census data reveals that these highly palatable yet highly manipulated food products constitute a significant portion of American diets. Over 58 percent of calories consumed by adults and a staggering 67 percent consumed by children in the United States are derived from ultraprocessed foods, marking a concerning dietary trend.
The proliferation of ultraprocessed foods has also sparked intense discussions on the global stage about their impact on public health and nutrition. Over the past decade, researchers have intensified efforts to define ultraprocessed foods and explore their potential health correlations. A series of recent studies have linked these foods to a heightened risk of various conditions, including cardiovascular disease, cancer, obesity, and depression.
However, amidst these concerns, some researchers and industry representatives raise questions about the strength of the evidence against ultraprocessed foods. They argue that the category’s definition is insufficiently precise, and the research findings are largely circumstantial. Moreover, they emphasize the role of industrial food processing in ensuring affordability, safety from foodborne pathogens, ease of preparation, and sustainability through innovations such as plant-based alternatives to meat and milk.
Ciarán Forde, a researcher specializing in sensory science and eating behavior at Wageningen University in the Netherlands, highlights the importance of a nuanced approach, stating, “You cannot throw the baby out with the bathwater and decide that you’re going to just dump everything” labeled as ultraprocessed.
Amidst this ongoing debate, one potential way forward is to invest in understanding the mechanisms through which ultraprocessed foods affect health. Researchers advocate for identifying the qualities that make these foods both appealing and detrimental to health by conducting studies involving carefully formulated diets and monitoring consumption behavior. Such research could pinpoint the most harmful types of ultraprocessed foods, enabling the implementation of warning labels and other policies. Additionally, it could guide companies in reformulating their products to offer healthier alternatives.
Filippa Juul, a nutritional epidemiologist at New York University, stresses the importance of delving into the biological mechanisms, stating, “I think the biological mechanisms are really important both to strengthen the evidence, but also to find solutions.” She, however, believes that there is already sufficient evidence regarding the harmful effects of ultraprocessed foods to recommend reduced consumption.
Defining ultraprocessed foods remains a contentious issue. While food preparation has historically involved processes like grinding, cooking, and fermenting, ultraprocessed foods, according to the widely used NOVA classification system, feature additional industrial techniques and ingredients uncommon in home kitchens, such as emulsifiers, thickeners, and flavor additives.
Most evidence suggesting the harm of ultraprocessed foods comes from observational studies, which reveal correlations between their consumption and various health issues. However, these studies cannot establish causation due to confounding variables. Nonetheless, the consistent association between ultraprocessed foods and poor health across diverse research from around the world is noteworthy. Adjusting for nutritional quality differences has failed to fully explain this link, suggesting that factors beyond nutrient content are at play.
Only one short-term randomized controlled trial has been conducted so far, revealing that participants consumed more calories and gained weight on an ultraprocessed diet compared to a minimally processed one. This result has prompted further questions about why we consume more ultraprocessed foods and whether all types of ultraprocessed foods have similar effects. Kevin Hall, a scientist specializing in nutrition and metabolism at the National Institutes of Health, believes that not all ultraprocessed foods have identical impacts, citing a 2023 study that found varying risks associated with different food types within the ultraprocessed category.