The magnesium-sodium-potassium balance is usually the reason for water retention.
Zinc is more concentrated in meat, yes, but a bit easier to absorb from greens, as I've been finding out. ;)
I find zinc supplementation to be gentler in a vitamin with selenium, C and B1.
It always pays to go gentle in changes to the body, of course.
Copper is especially rich in beer, grains, etc, so if you go the zincroad, there's a good way to balance. Cracked organic kernels like buckwheat and rye are quite nice (Though I know there's a lot of push for plain vegetarian and fruitarian here, I take it in cycles.)