ClucksAndCombs
Free Ranging
Wont' hurt them and any left over meat is full of protein and vitamins. But in moderation as too much "seafood" can taint the flavor of your eggs. So treat it like any other treat. No more than 10% of total diet for treats. Fish and crab meal are common ingredients in chicken feeds.
Oh yeah- I don't want obese chickens either xD. I'd give a lobster before I go on trips, and they can pick on that for the whole day. There isn't much left in the lobster when they eat it, and between 12, it's not much at all.
Also, be prepared for your coop to smell like seafood for a few days xD.