I was instructed not to give too much food to my rabbit to eat. Then one day, I found that my friend's rabbit was so heavy and full of "flesh" under the fur. So, I figured that my rabbit is under nourished.
We also realised that he is getting smarter. If the door to the cage is not fully latched, he knows how to open the door.
So, he is eating anything... rice, orchid, etc.