So, my advice is, "don't pick a clearly deficient diet, and don't not pick (i.e. default diet)"- beyond that, it doesn't seem like you can do much besides match to your individual tastes. I think it would take a health benefit of 10 extra years for me to give up bread, since I really like bread.

I hear you. Paleo = NO bread. I am not choosing to go that far. Seven months ago I had grains at the base of the food pyramid at ~ 40% of my daily calorie intake. Now it is less than 5% and the idea of eating a foot long subway is not appetizing to me at all right now. I am genetically European and I eat dairy and I consume alcohol; it is interesting and disturbing to observe at first hand people who dairy and alcohol make physically ill because they have some different G-A-T-C sequences deep in the works of the organism.

It is a mystery at this point. I have the latest American Dietetic Association Complete Food and Nutrition Guide. They have the food pyramid with grains at the base just like they showed us all in elementary school. My recent experience is that for my bio makeup that pyramid is not the best guide.