A recent study conducted by researchers at UCL has revealed that individuals consuming high amounts of ultra-processed foods (UPF) are at a higher risk of developing type 2 diabetes. However, this risk can be mitigated by opting for less processed foods.
The findings, published in The Lancet Regional Health – Europe, in collaboration with experts from the University of Cambridge and Imperial College London, examined how the level of food processing is related to the risk of type 2 diabetes, specifically identifying which types of UPF pose the greatest risk.
The research team analyzed dietary habits and health outcomes of 311,892 participants from eight different European nations over an average period of 10.9 years, during which 14,236 cases of type 2 diabetes were identified.
The study highlighted that for every 10% rise in ultra-processed food consumption, there was a corresponding 17% increase in the likelihood of developing type 2 diabetes. However, this risk can be reduced by incorporating less processed foods into the diet.
The types of UPF that posed the most significant risks were savory snacks, processed animal products like meats, ready-made meals, and both sugar-sweetened and artificially sweetened drinks, indicating the need for careful consideration of these food items to address health concerns.
Food processing levels are often classified using the Nova system, which categorizes foods into four groups: unprocessed or minimally processed foods (like eggs, milk, and fruit); processed culinary ingredients (such as salt, butter, and oil); processed foods (like canned fish, cheese, and beer); and ultra-processed foods (including ready-to-eat meals, savory snacks, pastries, and desserts).
While the exact reasons for the link between UPF and type 2 diabetes are not entirely clear, various factors—including overconsumption and resulting weight gain—are believed to play a role. Previous research indicated that increases in body fat accounted for about half of this connection.
Samuel Dicken, the lead author from UCL Division of Medicine, noted, “Our results reaffirm the known association between ultra-processed foods and the heightened risk of diseases such as type 2 diabetes. Our research confirms that even minor increments in UPF consumption lead to considerably increased diabetes risk.”
“Most prior studies examined UPF in general, but we believe different types of UPF carry different risks, and there hasn’t been extensive research on the other processing categories. Our analysis further explores all four groups in the Nova classification to evaluate how replacing UPF with less processed foods impacts diabetes risk, while also investigating nine specific UPF subcategories.”
“Encouragingly, we found that swapping out UPF for less processed options was linked to a lowered risk of type 2 diabetes.”
In this investigation, UCL researchers utilized data from the EPIC study, which focuses on assessing how diet, lifestyle, and environmental elements correlate with chronic disease occurrence among over half a million Europeans over time.
The team further refined their analysis by categorizing UPF into nine subgroups1, enabling a more nuanced understanding of how food processing levels relate to type 2 diabetes risk.
In addition to examining the influence of UPF on diabetes risk, the researchers employed substitution modeling to predict how replacing one Nova classification group with another would alter diabetes risk.
The findings demonstrated that replacing 10% of UPF in one’s diet with 10% of minimally processed or processed culinary ingredients lowered diabetes risk by 14%. When participants swapped 10% of UPF for 10% of processed foods, the risk decreased by 18%. This reduction may relate to the fact that 30-50% of processed foods consumed in this study comprised beer and wine, previously linked to diminished diabetes risk in another EPIC study. Processed foods also include items like salted nuts, artisanal breads, and preserved fruits and vegetables.
Analyzing the nine identified UPF subgroups, researchers found that savory snacks, animal-based products, ready-made meals, and sweetened beverages had the highest association with increased type 2 diabetes instances.
In fact, for those in the top 25% of UPF consumers, who derived 23.5% of their total dietary intake from UPF, sweetened drinks accounted for nearly 40% of their UPF consumption and 9% of their entire diet.
Conversely, UPF items like breads, biscuits, breakfast cereals, sweets, desserts, and plant-based alternatives were associated with lower chances of developing type 2 diabetes.
Professor Rachel Batterham, a senior author on the study from UCL Division of Medicine, remarked, “The subgroup analysis sheds light on the fact that not every food classified as UPF carries the same health risks.”
“For instance, breads and cereals are staples in many diets, and based on our findings, it’s essential to distinguish them from savory snacks or sugary drinks when providing dietary guidelines.”
The authors emphasize that since this study is observational, it cannot establish causal relationships, only associations.
The UCL team is currently conducting a trial aimed at assessing the impacts of UPF versus less processed diets, adhering to healthy eating recommendations, which will help clarify the findings of this research. Results from this trial are slated for publication in 2025.
In 2023, the UK Scientific Advisory Committee on Nutrition (SACN) reviewed existing evidence on UPFs, concluding that higher consumption levels of processed foods, especially UPFs, were linked to increased risks of health problems, including obesity, chronic diseases like type 2 diabetes, and even depression. The report also emphasized the need for further research to unravel the underlying causes of these associations.
Professor Marc Gunter from Imperial College London, an author of the study and co-coordinator of the EPIC study, commented, “This study contributes to the growing evidence linking UPF consumption to elevated risks of various chronic diseases, including obesity, cardiometabolic disorders, and certain cancers. Although this study cannot assert causal relationships, it suggests that reducing UPF intake and replacing them with whole, unprocessed foods could potentially lower the risk of type 2 diabetes. Further investigation into the mechanisms and possible causal pathways is essential.”
Note:
1 The nine subgroups included:
- Breads, biscuits and breakfast cereals
- Sauces, spreads, and condiments
- Sweets and desserts
- Savoury snacks
- Plant-based alternatives
- Animal-based products
- Ready-to-eat/heat mixed dishes
- Artificially and sugar-sweetened beverages
- Alcoholic drinks
- Other ultra-processed foods
