No, I do mean precisely the average muscle mass is higher. Granted we are dealing with statistics. There is inevitably a lot more context than just a myopic focus on this single fact.
This is particular relevant in the military because your fitness level is graded relative to you BMI. Hence, it is common trope one hears in the military. It is a practical question in the military. If the BMI is based on 1950's pilots and today's soldiers have a higher average BMI, then it can have an impact on promotions, fitness scores, health assessments, etc.
Dated but still relevant: https://cepr.org/voxeu/columns/evolution-bmi-values-us-adult...
This is particular relevant in the military because your fitness level is graded relative to you BMI. Hence, it is common trope one hears in the military. It is a practical question in the military. If the BMI is based on 1950's pilots and today's soldiers have a higher average BMI, then it can have an impact on promotions, fitness scores, health assessments, etc.