Research Shows Ultra-Processed Diet Linked to Higher Risk of Premature Death

A new meta-analysis involving more than 240,000 people found that adding more ultraprocessed foods to your diet increases the risk of dying prematurely from any cause. Researchers examined deaths occurring between ages 30 and 69, a period when death would be considered premature. The study, published Monday in the American Journal of Preventive Medicine, builds on growing evidence linking ultraprocessed food consumption to negative health outcomes across multiple countries and populations.

For each 10% increase in total calories from ultraprocessed foods, the risk of dying prematurely rose by nearly 3%, according to study coauthor Carlos Augusto Monteiro, emeritus professor of nutrition and public health at Brazil’s University of São Paulo. Monteiro coined the term “ultraprocessed” in 2009 when he developed NOVA, a system classifying foods into four groups by their level of processing. The system has since become widely used in nutrition research globally.

By Monteiro’s definition, ultraprocessed foods contain almost no whole foods. Instead, they are manufactured from “chemically manipulated cheap ingredients” and often use “synthetic additives to make them edible, palatable and habit-forming.” The NOVA system’s group one includes unprocessed or minimally processed foods like fruits, vegetables, meat, milk, and eggs. Group two includes culinary ingredients such as salt, herbs, and oils. Group three consists of processed foods combining the first two groups, while group four encompasses ultraprocessed foods.

Small Daily Increases Show Significant Health Impacts

This study is not the first to find an association between negative health outcomes and small increases in ultraprocessed food. A February 2024 study found “strong” evidence that people who ate more ultraprocessed food had a 50% higher risk of cardiovascular disease-related death and common mental disorders. Researchers in that study defined a higher intake as one serving or about 10% more ultraprocessed foods per day, demonstrating that even modest consumption changes carry substantial health risks.

Higher intake of ultraprocessed foods might also increase the risk of anxiety by up to 53%, obesity by 55%, sleep disorders by 41%, development of type 2 diabetes by 40%, and the risk of depression or an early death from any cause by 20%, according to the February 2024 study. A May 2024 study found that adding just 10% of ultraprocessed food to an otherwise healthy diet may increase the risk of cognitive decline and stroke.

Research from 2023 determined that including 10% more ultraprocessed foods was linked to a greater chance of developing cancers of the upper digestive tract. It’s estimated that as much as 70% of the US food supply is ultraprocessed. Two-thirds of the calories children consume in the US are ultraprocessed, while about 60% of adult diets are ultraprocessed, according to Fang Fang Zhang, associate professor at Tufts University in Boston.

Global Estimates Reveal Preventable Death Burden

Researchers estimated how many deaths might be prevented in eight countries with low, medium, and high consumption of ultraprocessed foods. “Premature preventable deaths due to the consumption of UPFs can vary from 4% in countries with lower UPF consumption to almost 14% in countries with the highest UPF consumption,” lead study author Eduardo Augusto Fernandes Nilson, a researcher at the Oswaldo Cruz Foundation in Rio de Janeiro, said. The calculations compared actual death rates to theoretical scenarios with reduced ultraprocessed food intake.

The United States has the highest level of ultraprocessed food consumption in the world, nearly 55% of the average American’s diet, according to the study. Researchers estimated that reducing the use of those ultraprocessed foods to zero would have prevented over 124,000 deaths in the US in 2017. In countries where consumption is low, such as Colombia at 15% of the diet and Brazil at 17.4%, reducing use to zero would have prevented nearly 3,000 deaths in Colombia in 2015.

Brazil’s reduction to zero would have prevented 25,000 deaths in 2017, according to the study. However, nutrition scientist Nerys Astbury, an associate professor at the University of Oxford in the UK, noted limitations in the research methodology. The study was unable to determine if the deaths were “caused by UPF consumption,” Astbury said, adding that “the methods of this study simply cannot determine this.” Astbury, who was not involved in the study, emphasized that observational research cannot establish direct causation between diet and mortality outcomes.

Experts Debate Methodology and Realistic Health Goals

“The authors set the theoretical minimal risk level to be 0. This implies a scenario where all UPFs are eliminated, which is highly unrealistic and nearly impossible in our current society,” Zhang said in an email. “As a result, the estimated burden of premature death due to UPFs could be overestimated.” Stephen Burgess, a statistician at the MRC Biostatistics Unit at the University of Cambridge in the UK, said that while the study cannot prove that consumption of ultraprocessed foods is harmful, it provides evidence linking consumption with poorer health outcomes.

“It is possible that the true causal risk factor is not ultraprocessed foods, but a related risk factor such as better physical fitness, and ultraprocessed foods is simply an innocent bystander,” said Burgess, who was not involved in the study. “But, when we see these associations replicated across many countries and cultures, it raises suspicion that ultraprocessed foods may be more than a bystander,” he added.

The food industry has pushed back against the findings. Sarah Gallo, senior vice president of product policy for the Consumer Brands Association, said the study is misleading and will lead to consumer confusion. “Demonizing convenient, affordable and shelf ready food and beverage products could limit access to and cause avoidance of nutrient dense foods, resulting in decreased diet quality, increased risk of food-borne illness and exacerbated health disparities,” Gallo said in an email. “No reason exists to believe that humans can fully adapt to these products,” Monteiro cowrote in a 2024 editorial in The BMJ.