I agree that certain breeds shed a lot and season is usually the primary reason for more shedding in these breeds. Shedding can also occur with certain medical problems such as some internal medical diseases or skin diseases eg. parasites or allergies etc. which have been undetected.
Sometimes unbalanced or cheaper diets don't have enough nutrition for a healthy coat - diet does play a role but it is not a type or specific brand that does it. The better quality foods usually have correct levels of the omega 6 and 3 oils and in the correct ratio which are important for a heatlhy coat. These are the foods you want to keep your pet on.
As long as the coat is healthy just use slicka brush or shedding tool/rake on a regular basis to help remove all the dead fur.
Martin Slome DVM
Centre Street Animal Hospital
7700 Bathurst Street
Tel: (905) 771-9855