Association between body weight time in target range and risk of type 2 diabetes in adults with obesity

Background Obesity is a major risk factor for type 2 diabetes, emphasizing the need for effective weight management strategies for its prevention and control. This study evaluated the association between body weight time in the target range (TTR) and the risk of type 2 diabetes in adults with obesity. Methods Using the 2010–2022 Korean National Health Insurance Service database, 248,367 obese participants with no history of diabetes were included. Body weight TTR was defined as the proportion of time maintaining a ≥ 3% reduction from baseline body weight. Participants were categorized into body weight TTR groups of 0%, > 0–50%, and > 50–100%. The primary outcome was the incidence of type 2 diabetes. Cox proportional hazards models were used. Results During a median follow-up period of 5.6 years, 46,737 (18.8%) of the 248,367 individuals with obesity developed type 2 diabetes. Compared to individuals with TTR = 0%, those with TTR > 0–50% and > 50–100% exhibited significantly lower risks of type 2 diabetes, with adjusted hazard ratios (aHR) of 0.86 (95% confidence interval [CI]: 0.84–0.88) and 0.66 (95% CI: 0.64–0.67), respectively. A 10% increase in body weight TTR was significantly associated with a decreased risk of type 2 diabetes (aHR: 0.95, 95% CI: 0.95–0.96) after adjusting for covariates. Conclusion In adults with obesity, a higher body weight TTR was significantly associated with a reduced risk of developing type 2 diabetes, highlighting the importance of sustained weight management in reducing the risk of type 2 diabetes.