I agree with the others here. I wouldnt worry about it all. It sounds as though what you are eating is really good for you and just what bubs needs. You would be doing yourself and bubs more harm if you denied food when you were hungry.
If I didnt eat for a period of more than 2-3 hours I would get dizzy and shaky and nauseous, I think it gave me low blood sugar or something.

Alot of weight does come off straight after the birth as well. I lost 12kg in 2 weeks. But that is because I had put a whopping 37kg on during pg...(I only put on so much because I had given up smoking and previously stuffed up my metabolism due to an unhealthy lifestyle!)