Introduction Today, the prevalence of overweight and obesity is, respectively, 49% and 17% among French adults. This research investigates their existence in the French Armed Forces, in terms of the impact on military operative response and military readiness. As no previous studies have evaluated the weight status of the whole French Armed Forces, this work assesses the situation for the first time in France. Material and Methods A prospective cross-sectional study was carried out between September 2016 and April 2017. A single anonymous questionnaire gathered the sociodemographic variables and usual care medical data. The source population was active duty members serving in units reporting to the South-Eastern French Regional Military Health Department. Results Among 1,589 respondents, prevalence of overweight and obesity was, respectively, 38.7% and 10%. Mean waist circumference was 78.2 ± 9.1 cm for women and 89.1 ± 10.5 cm for men. A third of female military and one-fifth of male military had a measure bigger than the standard International Diabetes Federation. Age, sex, weekly fitness activity, and rank were significant independent predictors of body weight excess. Less than 5% of the study population reported a diagnosis of comorbidity: diabetes 2%, high blood pressure 1%, and dyslipidemia 1.5%. Conclusions As all armies, the French Armed Forces are affected by obesity. Nevertheless, the prevalence of obesity seems lower than in other Western armies. In the French army, as in the general population, obesity is correlated with socioeconomic status and level of education. However, compared to the general French population, there is less obesity and overweight in the French Armed Forces. Moreover, overweight and obese military members have a lower cardiovascular risk than their civilian counterparts. Enlistment standards, military occupational activity, and a mandatory high level of physical fitness could explain these different proportions of overweight and obesity. This raises the question of the protective effect of regular physical activity. Is this a serious way to fight against the growing prevalence of overweight and obesity in Western countries? Indeed, this is a significant public health issue, which also affects the military’s quick response force capacity and strategic capabilities. Therefore, the identification of specific demographic characteristics should be considered in developing prevention programs.