Regarding dairy, milks from common CAFO sources and mass produced cheese created using 'enzymes' are probably worse for the body than grass-fed milk and animal rennet made cheeses.
Personally when I have the former, I will get acne breakouts. Also high fat in general, even if saturated, causes me acne. Extra zinc sometimes helps.
Anecdotal of course, everyone handles these things differently, but something to consider.