Originally posted by jonnin:

depending on how many you actually have, you can safely toss some.
even with the food and portals and torches and all, you likely have 10-20 times what you really need.
Iron is plentiful, its just tedious to get in large amounts. Ive got probably 1000 + bars in supports in buildings now.

How many you need probably depends on how many greydwarves you kill and how long you spend in the mountain biome before advancing to bread. I ate about half my eye supply in eyescream before I made it to onion soup.