Ultra-processed food intake and risk of type 2 diabetes in a French cohort of middle-aged adults

Abstract Objective The consumption of ultra-processed foods has been increasing during the last decades, and has been previously associated with increased risks of mortality and several chronic diseases. The objective of this study is to assess for the first time the prospective associations between consumption of ultra-processed foods and the risk of type 2 diabetes (T2D). Methods 104707 participants aged at least 18 years (median age 41.5 years) from the French NutriNet-Santé cohort (2009-2019). Dietary intakes were collected using repeated 24 hour dietary records, designed to register participants’ usual consumption for 3300 different food items, categorized according to their degree of processing by the NOVA classification. Associations between ultra-processed food intake and risk of T2D were assessed using multi-adjusted Cox proportional hazard models. Results Ultra-processed sugary products, fruits and vegetables, and beverages were the highest contributors of the ultra-processed category (respectively 27.9, 18.5 and 15.6%). Ultra-processed food intake was associated with a higher risk of T2D (n = 821 incident cases; hazard ratio for an absolute increment of 10 in the percentage of ultra-processed foods in the diet = 1.15 (1.06-1.25); P = 0.0009, 582252 person-years). These results remained statistically significant after adjustment for other metabolic comorbidities, for several markers of the nutritional quality of the diet (red meat and sugary drinks consumption, intakes of saturated fatty acids, sodium, sugar, dietary fiber or Healthy/Western patterns derived by principal component analysis) and after a large range of sensitivity analyses. Conclusions In this large observational prospective study, higher consumption of ultra-processed foods in the diet was associated with a higher risk of T2D. Public health authorities in several countries recently started to recommend privileging unprocessed/minimally processed foods and limiting ultra-processed food consumption. Key messages The consumption of ultra-processed food is associated with an increased risk of type 2 diabetes. As the French Public Helath agency recommends, their consumption should be limited. Nutritional composition, food additives, contact materials, or neoformed contaminants might play a role in these associations and further studies are needed to understand their relative contribution.