Deer meat is very lean, and very high in protein, but to have a diet of only wild meat is not the smartest choice. Eating lots of venison and wild game you may develop Gout (sp?) as well.
I wouldnt recommend eating just deer meat. If you want lean meat go with chicken. If you want to eat healthy, eat things like chicken, rice, wheats, oatmeal, etc, etc. And stay away from fried foods like french fries. Pizza is a hard one to stay away from but you should stay away from stuff like that. Check nutritional facts, stay away from saturated and trans fats. Look for monounsaturated and polyunsaturated(?) fats in things like cashews, and any type of nuts. Just not deer nuts. Human nuts go without saying.