Ultra-processed Food Intake and Risk of Type 2 Diabetes in Korean Adults

Several studies from the United States and European countries reported a positive association between ultra-processed food intake and diabetes risk. However, little is known about the association in Asian populations. It is also unknown about the individual ultra-processed food items that are most unfavorably associated with diabetes risk. We examined the associations of ultra-processed food intake (combined, as well as individual ultra-processed food items) with the risk of type 2 diabetes. This prospective analysis included 7438 participants aged 40-69 y from the Korean Genome and Epidemiology Study Ansan-Ansung cohort. Dietary intake was assessed at baseline using a 103-item semiquantitative food-frequency questionnaire. Ultra-processed foods were classified using the Nova definition. Incident type 2 diabetes cases were identified via follow-up interviews and health examination. Multivariable Cox proportional hazard models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs), adjusting for potential confounders. During the follow-up (2001-2019; median: 15 y), a total of 1187 type 2 diabetes cases were identified. Compared with the lowest quartile of ultra-processed food intake, the highest quartile was positively associated with diabetes risk [HR (95% CI) = 1.34 (1.13, 1.59), P-trend = 0.002]. The association did not change after additional adjustment for diet quality or BMI. Among individual ultra-processed food items, a higher consumption of ham/sausage [per 1% increase in the weight ratio: HR (95% CI) = 1.40 (1.05, 1.86)], instant noodles [1.07 (1.02, 1.11)], ice cream [1.08 (1.03, 1.13)], and carbonated beverages [1.02 (1.00, 1.04)] were associated with an increased risk of type 2 diabetes, whereas a higher intake of candy/chocolate was associated with a decreased risk [0.78 (0.62, 0.99)]. Our data suggest that the high intake of ultra-processed foods, particularly ham/sausage, instant noodles, ice cream, and carbonated beverages, is associated with an increased risk of type 2 diabetes in Korean adults.