Association between ultra-processed food consumption and the incidence of type 2 diabetes: the ELSA-Brasil cohort

BACKGROUND: Ultra-processed food (UPF) consumption increases the risk of type 2 diabetes in various high-income countries, with some variation in the magnitude across studies. Our objective was to investigate the association of UPF consumption and specific subgroups with incident type 2 diabetes in Brazilian adults. METHODS: The Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) is a multicenter cohort study of 15,105 adults (35–74 years) enrolled in public institutions in Brazil (2008–2010). We followed participants with two clinic visits (2012–2014; 2017–2019) and annual telephone surveillance. After excluding those with diabetes at baseline, who died or were lost in the follow-up, with missing data, with implausible energy food intake, or reporting bariatric surgery, there were 10,202 participants. We used the NOVA classification to assess UPF consumption based on a food frequency questionnaire. We defined type 2 diabetes by self-report, medication use, or comprehensive laboratory tests. We estimated relative risks (RR) and 95% confidence intervals (95% CI) using robust Poisson regression. RESULTS: Median UPF consumption was 372 g/day. Over 8.2 (0.7) years of follow-up, we detected 1799 (17.6%) incident cases. After adjustment for socio-demographics, family history of diabetes, and behavioral risk factors, comparing the fourth (≥ 566 g/day) with the first (< 236 g/day) quartile of UPF distribution, RR was 1.24 (1.10–1.39); every 150 g/day increments in UPF consumption resulted in a RR of 1.05 (1.03–1.07). Reclassifying natural beverages with added sweeteners as UPF increased risk (RR 1.40; 1.25–1.58). Among UPF subgroupings, consumption of processed meats and sweetened beverages increased diabetes risk, while yogurt and dairy sweets decreased the risk (p < 0.05). CONCLUSIONS: UPF consumption increased the incidence of type 2 diabetes in Brazilian adults, with heterogeneity across specific food items. These findings add to previous evidence for the role of UPFs in the development of diabetes and other chronic diseases, supporting recommendations to avoid their intake in diabetes prevention and management. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13098-023-01162-2.