Speedo?
The last scene where Scott tells his new wife to not pick a tropical location for their honeymoon because "you don't want to see this in a speedo", gave me an idea.
They could have written it that Scott or any person installed as the Big Guy would "desantify" after Christmas and start resantifying right after Thanksgiving the next season. Scott was a decent looking guy in really good shape before he got the job, but the tradeoff of getting the job is morbid obesity, even if he's somehow protected from the health aspect of it.
I'm sure Carol would have preferred the look Scott had at the school Christmas party.