Most everyone does, and switching to Paleo/Zone doesn't leave a person much in the way of options if a recipe calls for breadcrumbs or batter... Our fellow CrossFitter Blake got creative with flax and walnuts, and found a perfect substitute.
Take a pork tenderloin, slather it in dijon mustard, then rub it with a mixture of ground walnuts, flax meal (optional) and any seasoning you wish (I just use a little salt & pepper). Put a little olive oil in an oven-safe pan, sear it all over, then finish it in the oven, uncovered, at 375 until cooked through (depending on size, probably 10-20 minutes oven time). In the summer, to stay cool, I cut the tenderloin into medallions and individually rub them with mustard & walnut mixture, then brown them on each side in the skillet, covering with a lid to cook through, about 5 minutes per side. Finish searing without the lid on, to get more crispness. Once cooked, let the meat rest on paper towels to absorb any extra oil.
I also use the same technique with cod, and you could use any fish you like, or chicken. Basically anything you'd otherwise douse with bread crumbs, you can substitute in this recipe.