I had hyperemesis in my last pregnancy for the whole 9 months, I threw up everyday/night non stop. I could barely eat anything and most of what I did eat came back up within 20 mins or so, it got a bit less towards the end but still wasn't eating a lot, I lost 2 stone during the pregnancy and my daughter was 8lb 12oz!! Don't know where she got all the weight from lol! I was so worried about her during the pregnancy that she was going to be weak and tiny, but she always measured right for weeks and she was huge, healthy and strong as an ox! haha So my eating certainly didn't affect her