Squid actually has quite a bit of nutritional value because of the high amount of omega 3 fats it contains as well as lots of protein, iron, and other minerals that are essential for a healthy body. You will find that seafood as a whole is very good for you and should be eaten as often as possible.
There are many different types of fish, crustaceans, and mollusks that are both delicious and nutritious, so you will be able to get everything you need without feeling guilty afterwards. If you are looking for certain types of food with significant nutritional value, you will certainly want to look to squid because of all that it has to offer.