I'm not even sure eating has a great deal to do with it. I had HG with DS3 and DD so was pretty much completely starved and dehydrated for the first 5 months with DS3 and better medicated with DD so could eat and drink a bit more with less vomiting. Still they were both heavier than DS1 and not really what I'd call small babies.
Did you find that the HG tended you towards certain foods? Did you eat more refined carbs with those pregnancies?