Some observations:
1) Young kids and teens don't get nearly as much exercise in school as we once did because P.E. and recess time have been drastically reduced over the years so that the kids are effectively chained to their desks to get more "instructional time." I see it with my two kids currently in school.
2) Kids don't go outdoors and play like we did for various reasons, including video games, television, and safety (with child predators seemingly infesting every community these days).
3) On base food courts and fast food joints serve mostly junk to the troops in garrison.
4) The proliferation of "mandatory training" and "administrative/staff duties" in today's military keep the troops, especially officers, sitting flat on their butts many days in cubes, offices, and/or auditoriums, instead of out in the field.