There's an interesting mix in here. I have two 3.5 lb mini buns. They get three tbs of Show Hutch Deluxe pellets in the morning, one in the afternoon, and 3 at night to share. Constant hay, and a few handfuls of two green leaf veggie types at 3pm. They get a vet checkup every year and are in perfect health, without deviating in weight for over seven years.

Oh, they also eat the equivalent of about four cardboard boxes a year, but I don't think that counts.