Replacing Ultra-processed Items in the Diet improves Type 2 Diabetes Risk

People who consume more ultra-processed foods (UPF) are more likely to acquire type 2 diabetes, but this risk can be reduced by eating fewer processed foods, according to a new study headed by experts at UCL.

The study, published in The Lancet Regional Health — Europe in partnership with experts from the University of Cambridge and Imperial College London, looked into the association between food processing and type 2 diabetes risk, as well as which types of UPF were more at risk.

The study looked at UPF consumption and health outcomes for 311,892 adults in eight European nations for an average of 10.9 years, during which 14,236 persons got type 2 diabetes. They discovered that every 10% increase in the amount of ultra-processed foods in a person’s diet is associated with a 17% rise in type 2 diabetes risk, which can be reduced by eating less-processed foods instead.

Savoury snacks, animal-based items such as processed meats, ready meals, and sugar-sweetened and artificially-sweetened beverages were the greatest risk UPF groupings, indicating that these foods should be given special attention in order to combat illness.

The UPF subgroup analysis in this study has been revealing and confirms that not all foods categorised as UPF are alike in terms of the health risks associated with them. Breads and cereals, for example, are a staple of many people’s diets.
Rachel Batterham

The Nova classification is commonly used to assess the degree of processing in foods. It divides foods into four categories: unprocessed or minimally processed foods (MPF) like eggs, milk, and fruit; processed culinary ingredients (PCI) like salt, butter, and oil; processed foods (PF) like tinned fish, beer, and cheese; and ultra-processed foods like ready-to-eat/heat mixed dishes, savory snacks, sweets, and desserts.

The specific origins of the association between UPF and type 2 diabetes remain unknown, although various factors, including overconsumption and weight increase, are considered to be involved. In a prior study, which was supported by fresh data in this study, higher body fat accounted for around half of the connection.

Samuel Dicken, first author of the study from UCL Division of Medicine, said: “We know that ultra-processed foods are associated with a higher risk of certain diseases such as type 2 diabetes. As expected, our findings confirm this link and show that every 10% increase in the diet from UPF increases the risk of developing type 2 diabetes considerably.

Replacing ultra-processed foods in diet reduces type 2 diabetes risk

“Most studies to date only consider UPF as a whole, but we also suspect that there may be different risks associated with different types of UPF, and the risks of other processing groups have not been well researched. Our analysis goes a step further than previous studies, by looking at all four processing groups in the Nova classification to gauge the impact on type 2 diabetes risk when we substitute UPF with less processed foods, as well as looking at nine UPF subgroups. The good news is that replacing UPF with less processed foods was associated with a reduced type 2 diabetes risk.”

UCL researchers analyzed data from the EPIC study, which looked at the association between nutrition, lifestyle, and environmental factors and the development of chronic diseases in over 500,000 Europeans over time. Additional data analysis was conducted to divide UPF into nine subgroups1 in order to better understand how the level of processing influences type 2 diabetes risk.

In addition to analyzing how eating UPF affects a person’s risk of getting type 2 diabetes, the researchers used substitution modeling to investigate how replacing one Nova food group with another would alter type 2 diabetes risk. The study found that replacing 10% of the UPF in the diet with 10% of the MPF/PCI lowered the risk of type 2 diabetes by 14 percent.

Substituting 10% of UPF in the diet with 10% of PF reduced diabetes risk by 18%. The authors say this may be down to the fact that 30-50% of PF intake in this study came from beer and wine, which have been associated with a lower risk of type 2 diabetes in a previous EPIC study. PF also includes salted nuts, artisanal breads, and preserved fruits and vegetables.

Analysis of the nine UPF subgroups showed that savoury snacks, animal-based products, ready meals, and sugar-sweetened and artificially-sweetened beverages were associated with higher incidence of type 2 diabetes.

High proportions of these less healthy foods contributed to overall type 2 diabetes risk. In the top 25% of UPF consumers, where UPF made up 23.5% of their total diet, sweetened beverages alone accounted for nearly 40% of their UPF intake and 9% of their diet overall. However, UPF breads, biscuits and breakfast cereals, sweets and desserts, and plant-based alternatives were associated with lower incidence of type 2 diabetes.

Professor Rachel Batterham, senior author of the study from UCL Division of Medicine, said: “The UPF subgroup analysis in this study has been revealing and confirms that not all foods categorised as UPF are alike in terms of the health risks associated with them. Breads and cereals, for example, are a staple of many people’s diets. Based on our results, I think we should treat them differently to savoury snacks or sugary drinks in terms of the dietary advice we provide.”

According to the authors, the study’s observational nature limits its ability to measure causal effects. The UCL team is currently conducting a trial to compare the influence of UPF versus MPF diets on meeting healthy eating guidelines, which will help to clarify the findings of this study. The study results are expected to be published in 2025.

In 2023, the UK Scientific Advisory Committee on Nutrition (SACN) reviewed the available scientific evidence on UPFs and published a report concluding that increased consumption of processed foods, particularly UPFs, was associated with an increased risk of obesity, chronic diseases such as type 2 diabetes, and depression. The report also highlighted the need for additional research to understand the cause of these associations.

Professor Marc Gunter, an author of the study from Imperial College London and one of the EPIC study’s coordinators, stated: “The findings from this study add to the growing body of research that links UPF consumption with an increased risk of certain chronic diseases such as obesity, cardiometabolic diseases, and some cancers. While such a study cannot establish causative correlations, it does show that lowering intake of certain UPF and substituting them with unprocessed, whole foods may reduce the risk of type 2 diabetes. More investigation into mechanisms and probable causal pathways is now required.”

Note:

The nine subgroups were: