I think it makes a difference. If you overeat, even if it's healthy, it's got to go somewhere, and it's not necessarily bad. Imagine if you practically starved yourself, of course your baby would be smaller, so I guess it's the same in reverse. I put on 17.7kg and my baby was 8 10 (3.9kg). I am normally 57-58kg (163cm tall) if that's any help.