This longitudinal study examined sex‑specific changes in body composition across the first academic year in military university students using multi‑frequency bioelectrical impedance analysis (InBody 970). A total of 497 cadets (408 men, 89 women) were assessed at baseline and follow‑up. In both sexes, body mass increased primarily due to gains in fat‑free mass and skeletal muscle mass, accompanied by higher total body water and basal metabolic rate, while changes in adiposity indicators were small. Men exhibited greater increases in lean‑related parameters, whereas women showed a modest reduction in percent body fat. These findings support MF‑BIA as a practical tool for large‑scale monitoring of functional and medical readiness in military populations.