foods or supplements with calcium will block the absorption of ZMA, so you do wanna avoid dairy foods at bedtime if you take ZMA
ZMA does: help you sleep soundly at night; increase the quantity of ejaculate (I'm serious); help you maintain your baseline testosterone levels
ZMA does NOT: significantly increase testosterone (despite what you read); pack on massive amounts of muscle
basically its not a make or break supplement. but, since zinc can become deficient depending on your diet and calcium intake when eating zinc rich foods/supplements, this supp. can help maintain those levels, which would help you achieve your natural testosterone levels, which is of course important for muscle building AND fat loss.