I hope they don't deny him lean protein (like egg whites or a little boiled chicken). That will help his weight loss if fed in proper amounts.
One of the hazards of ownerships is that it's actually fun to watch them beg and eat, so they are easy to overfeed.
When we first got our baby skunk, Blossom, we didn’t know what to feed him, so I cut off a big chunk of cornbread and put it in his cage. I looked later and he was propped up in the corner with a very extended belly. It seems they don’t know when to stop eating. We raised him on cat food and the insects he could catch, also on the Japanese beetles the neighbors caught and brought to him.
Aren’t skunks vegetarians mostly? It’s not like a Dogs and Cats which are basically pure carnivores.