In today's world it's hard to know just what a "balanced" diet is.
Reading up on history, and gaining a basic understanding of how early man lived and what foods they could get - the answer is to remove new developments and look into modern agriculture and what foods come from where, and remove the modern. Foods that aren't manipulated before being put on the shelf, foods that grow naturally or are found in nature are all one needs. Foods that our early ancestors could hunt down, mix, chop up, cook, and eat.
I always eat farm-fed based meats for that reason. I don't like it that animals are kept in cages and injected with downers all their lives, and it is quite unhealthy to consume meats that have those hormones, or that have been mixed with all kinds of junk in factories. I normally stick with ground, farm fed turkey.