Targeting Habitual Fast Eating as a Modifiable Risk Factor for Type 2 Diabetes: A Propensity Score-Matched Analysis

INTRODUCTION: Type 2 diabetes remains a growing public health concern, and modifiable lifestyle behaviors represent a key target for prevention. Eating habits have been proposed to influence metabolic risk, yet evidence from large real-world cohorts with rigorous covariate control is limited. We hypothesized that habitual eating habits, especially eating speed, are a modifiable risk factor for incident type 2 diabetes in a Japanese adult population. METHODS: This retrospective observational study used lifestyle habit data from medical check-up records collected in Shizuoka, Japan (April 2008-March 2020). After applying exclusion criteria, 98,718 subjects aged 18-75 years were eligible for analysis. The analytic sample for each eating habit varied after propensity score matching. Cox proportional hazard regression was used to assess new-onset type 2 diabetes in relation to multiple eating behaviors, including eating speed, breakfast skipping, late dinners, post-dinner snacking and frequency of vegetable consumption. Covariate adjustment was performed using propensity score matching for sex, age, BMI, smoking and drinking status, blood pressure and LDL and HDL cholesterol levels. RESULTS: During the observation period, 4631 new cases of type 2 diabetes were identified. After full adjustment, fast eating was significantly associated with increased diabetes risk (HR: 1.12; 95% CI: 1.02-1.23; p = 0.01). Sex-stratified analysis showed that fast eating among women was associated with a 14% higher risk (HR: 1.14; 95% CI: 1.00-1.30; p = 0.03), while no statistically significant association was observed in men. CONCLUSION: Habitual fast eating may represent a modifiable risk factor for type 2 diabetes, particularly among women, though the association was modest and warrants confirmation in future clinical studies.