Feeling the spine?

2/3rds is pretty good. Sounds about right to me.

Deffinitely sounds right to Diamond too. I always find a bit left when I got to do the next feeding. So I may go ahead and drop her to 2/3rds since she is not eating it all anyway. Burnie however is a little vacuum anad would eat an entire bag of pellets if left to it. So I know I will have to watch him.

I'm a first-time rabbit owner, have had my minirex for over three years and I was shocked at how lean and lanky they are. I could feel his ribs and bumps in his spine, but the vet said he was a good weight at 4.5 pounds. (Just over 2 kilos for the rest of the world) Though if you are that concerned, like others are saying give some extra pellets to be safe until the vet weighs in.

I have a mini rex and she is exactly the same. She eats more than all my other rabbits; but she is still lanky. I can feel her spine and she is pretty "boney". I have taken her to the vet (she weighs 4 lbs.) and all checks out. I think it is just her "build". She has been the same weight as long as I have had her (she is 7) and is healthy.
I think your rabbit is fine. Rabbits like people just have their own unique frame. I wouldn't worry as long is your rabbit is healthy and eating normally.