I recall this being dissected in very fine detail in an elders/CO meeting years ago. Or maybe an elders school. It all tends to run together after a while.
Anyway, IIRC, the basic idea was that the bible condemns "gluttony", not "obesity". It was more about the attitude toward food as opposed to the quantity.
We had a special pioneer / elder who was pretty normal-sized, not big at all, who was legendary for the enormous and multiple 6 or 8 inch high plates he would put together for himself at congregation "get togethers" with food served buffet style. Like, seriously, the plate would be nearly as piled high as it was wide. Then he'd go back and do it again. And again. Then get a dessert plate or 3 or 4.
Never gained an ounce. It was a source of wonderment to everyone.
Anyway, once when a bunch elders were on a coffee break with a particularly zealous CO, we were laughingly recounting some of the awesome Joey-Chestnut-style sprees this guy would go on.
The CO suddenly grew deathly pale and exclaimed "That's gluttony!"
We had to talk him down from trying to remove the elder from his position, or who knows, maybe even try to DF him.