The Janitor has a normal weight, the Wax Bellman is basically anorexic and the Lady is normal weight too. The members of the staff are however relatively of 'healthy' weight compared to the Guests.
The reason for this is obviously their gluttony, which makes them eat constantly and might be because of either the Lady's hypnosis/magic or for psychological reasons (considering they go to this resort to get away from the Pale City's madness and cruelty, they most likely engage in every sinful activity that can bring them some 'positive' emotion).
Well, the Guests are morbidly obese compared to the Maw's staff to the point they can barely waddle and crawl around.
