Is there a food with all the nasty bits left out?

I have just read the ingredients of my dog's food and I have spent a hair-raising 30 minutes on the Internet googling all the weird things that are in her current diet!
Can anyone point out a food that doesn't have loads of preservatives, colourings, grains or chemical additives? What’s the choice out there? Surely someone is doing something that leaves all that nasty stuff out without me having to cook for my dog myself?
Dawn Morley, Wales