I bought a baby in August who was a CH July '06 baby, and she was only 80g when I got her. A week after I brought her home, she got a fat, small adult mouse and easily got it down. Now she gets a medium adult once a week and does just fine. She weighs 160g now and is a little chunker.

I'm sure ya'lls little boy would be just fine(and happier) with a slightly fuller belly.