Boyfriend is shallow, should I try to explain to him he's being shallow and make him understand his comments are not okay?

Long post, sorry.

Little background: all my life, I've often been a victim of mean comments about my appearance. I've been told I'm fat, I look like I'm pregnant because of my big belly and I've always been made to feel less valuable because of my looks. Appearance is a sensitive subject for me and while I'm now confident with myself, it bugs me when people comment on other people's looks.

My boyfriend and I were talking about babies today and he mentioned how he doesn't understand why people would want to take pictures when a child is born because "both the baby and the mother look terrible in that moment - the baby is all gross, and the mother is all fat and sweaty". I was shocked at this statement because, while I'm aware it's might not be the prettiest sight, it's still a beautiful moment of a child being born! Plus the comment about the mother being fat is just ridiculous. He also often makes comments about how people look and it makes me think he's really shallow. I told him it makes me feel like I'm under a lot of pressure to stay lean because if I put on weight, he might not like me anymore, to which he said that beauty comes from within and that, as long as I'm healthy, he's alright with me gaining weight, because he knows I'm a great person. But still, I can't keep thinking about his words and how shallow and horrible they sounded...

I don't know what to do, this is a fresh relationship, we haven't been together for a long time and I'm afraid these issues will become bigger with time. It makes me sick to my stomach that he would say something like that... Also I didn't react quite the way I wanted to, I tend to avoid conflict so I kept some things to myself which I'm now sorry I did, and I don't know if I should bring it up again.

I'm 29, my boyfriend is 31.