Wg,
As you are in the Army you will not understand the light blue way of life in the same way we are often bemused by the antics you mad pongo's get up to.
The fat knackers you and your colleagues so gleefully disparage will, almost certainly have passed their one and now two annual fitness tests so therefore they are "technically", fit despite not being pleasing on your rather critical eye.
The system sets a level of fitness we need to achieve which pretty much all of us attain with great ease and if some choose to see that as sufficient AND are still capable of carrying out their primary role then what is the problem