Rock Candy

The bump this gives is small, small enough that nobody builds around it. What matters is that it is not zero, and walking into a boss with no food buff at all is the most common free mistake in the game. Eat it once you are standing in the arena, not on the walk over, so the timer is not half gone before anything starts.

Anything higher on the ladder replaces it outright, so there is no reason to hoard a stack. If you have better food you should be eating that, and if you do not, the candy in your chest is doing nothing for you sitting there.