I'm new to ball pythons myself, but have learned that when they are in shed, they can turn into antisocial little beasties and it's best to leave them alone. Someone told me that much of it has to do with that opaqueness making it difficult for them to see. One of mine eats every time, shed or no shed, and another one goes off her feed when it happens. You could offer the meal and see if he'll take it.