Well, milk doesn't come out of the cow "low fat" or non-fat". If nature had intended it to be low fat or non-fat, it would have made cows that way long before genetic modification/alteration.
The more I read, the more convinced I am that "real" foods are the best foods for us. Afterall, we are "real". So why should we feed our real bodies with artificial junk?
So don't feel guilty about eating real food. It's more healthful and it's actually more environmentally friendly than eating the artificial stuff.