Well, with all of the toxins in dog foods these days I have been very cautious and worried, so when I began reading about things I realized that dogs were fed raw or people food up until the first dog biscuit was created by a sailor who ate those dry biscuits on the ship...he decided to add meats and things to a biscuit for his dogs and ... then they started to make canned foods but in WWI the aluminum or tin became scarce and they started making kibble.
The book points out that (and I have always felt this was true) feeding one brand of kibble or one brand of canned every day is boring for your dog as it would be for you.
They need mostly protein, a tiny bit of veggies (2 TBS) and then certain minerals/vitamins...in fact, they said that one of the best sources of protein is eggs.
This book says that you can feed what you eat and usually this makes you eat a better diet too. People food with high protein makes for smaller and less smelly poops too! Yahoo!
They said that you feed much less if the food is good quality, so it can be cheaper. You only need to feed grains and carbohydrates if the dog is in a life stage where energy is an issue, as for pups, elderly dogs, etc.