That may have changed in the last 18 years, but when my husband was in the Army, in the late 80's, a strict weight number was what they went by. My husband has been overweight his whole life, he was able to make the top part of the weight guidelines to get in, but he was unable to maintain it. He never failed a physical, and in PT he was constantly the #1 or #2 finisher. About 3 years into his 4 year commitment, the Army started a draw down of personnel. Things like no more reenlistment bonuses, no huge incentive to reenlist, etc. They also went back to their strict weight limits, so although my husband still met PT requirements he no longer met weight requirements so they stopped all his "perks". He could no longer take leave.
His last year in the service was miserable, and he did not reenlist.