Two of my dogs are on canidae.It has enough oils and stuff in it that they dont shed or have dandruff.My boy on wellness does shed a lil more.The two that are on canidae is a border collie and a rottie.I quit having to spend money on fish oils after switching to canidae.
You may not be able to stop the shedding with food, no matter what you use. Shedding is natural, it happens. However, if you have a dog with under coat and that undercoat is falling out because it is now spring. Go to a good dog groomer, tell them that you want the undercoat removed. They cannot brush it all out, but they have ways of cleaning out a great deal of the undercoat which will cut down a TON of the hair in your house.
A good bath, lots of shampoo in very warm water, and a brink towl dry will also help dogs without under coat drop a great deal of unwanted hair.
I've been feeding Eagle Pack and I notice the Holistic Anchovy, Salmon, Sardine and Oatmeal formula really reduces shedding.
I'm actually in the process of switching to Canidae though (a little cheaper from where I buy my food and I heard good things about it from people on here - the ingredients look great...).
You'll find premium foods often have Omega 3 & 6 fatty acids in them, this helps maintain a healthy coat and skin. Better quality food also allow more of the nutrition to go to the coat because the body is well maintained. This helps reduce shedding and dander.
Spaying/neutering - especially with longer coated breeds - will also reduce shedding as a portion of shedding is linked to hormones.
AND if you bathe your dog with a good Oatmeal based Shampoo that also helps. :)
(I raise Shelties - we're always thinking about shedding...)