My advice is: get him off of meow mix now! Meow mix is basically trash with a label that says "cat food" They compact all the inedible nutrition less left overs that they can't feed things like meat cows, and slap a label on it. Here's a guide line. If it is available at a regular grocery store, wal-mart, costco target or any non pet specialty store, don't feed it to your pet!
Do some research on hedgehog nutrition. Pay close attention to the protein and fat ratios that are healthiest for hedgies. Write them down and take it to the pet store. Try and find a food that's as close to his natural diet as you can. Things that are more "buggy" like crab or crawfish (it's out there)
I personally fed my hedgie Vita craft's sunseed hedgehog formula. It contained more buggy type ingredients, more suitable for a hedgehog.