Implications of obesity in the US military: unfit to serve?

Obesity remains a significant public health concern with substantial implications for military readiness. Rising rates of overweight and obesity among service members challenge recruitment, retention and deployability. Although the military continues to screen and manage obesity, current body composition tools and policies often fail to capture true health risk or operational capability. This narrative review evaluates the prevalence and impact of obesity in the US military, critiques existing assessment methods and discusses recent policy updates across service branches. Particular attention is given to limitations of traditional metrics such as body mass index and circumference-based measures, as well as the potential of modern approaches to improve accuracy and effectiveness. Despite policy revisions, obesity remains the leading medical disqualifier for service and a major contributor to lost workdays, injuries and medical costs. Aligning body composition standards with scientific evidence and operational demands is essential for supporting readiness across modern defence forces.