The protein in their flesh is concentrated, yes, and aquatic and semi-aquatic life is vitamin-rich.

(at least no one's dissing his food now. he's asked an interesting question though, which makes him look down at his own empty plate.)

This food is luxurious. There are things here that I was unable to obtain in my world. Cheese, butter—milk-based products, generally... Some of these recipes are things that the finest chefs in Resdayn couldn't have imagined, especially the desserts, which I have only looked at and not tried.