BMI Alterations and Prevalence of Overweight and Obesity Related to Service Duration at the German Armed Forces

The aim of this study was to assess body mass index (BMI) and the prevalence of overweight and obesity at entry and release of service at the German Armed Forces and related associations to service duration. In a cohort study, 85,076 paired BMI data sets (entry and release of service) of German soldiers (5.4% females) between 2010 to 2022 were analyzed retrospectively to assess BMI alterations and the prevalence of overweight (BMI ≥ 25) and obesity (BMI ≥ 30) after service durations of ≤2 years, 2–5 years, or ≥5 years. Between 2010 and 2022, we observed a trend for BMI increases of about 0.5 kg/m(2) (X(2) = 27.104, p = 0.007). BMI increases differed significantly (X(2) = 7622.858, p < 0.001) after ≤2 years (0.0 kg/m(2)), after 2–5 years (1.1 kg/m(2)), and after ≥5 years (2.4 kg/m(2)) and were correlated to service duration (r = 0.34, p < 0.001). The prevalence of overweight increased from 33.0% to 39.5%. Obesity prevalence increased from 3.7% to 6.3%. The switch to obesity was more pronounced for longer service durations. Although secular trends for BMI increases among soldiers were in line with the general population, service duration was related to BMI increases. Especially, the service time depending on pronounced prevalence of obesity should be a matter of debate leading to counteracting measures at the German Armed Forces.