I don't think so - as far as I know, baby takes what it wants from you, but I dont' think it matters if you are putting in extra calories in, it will take what it needs to grow.

I know smaller women than you that have had huge babies (bigger than 4kg) so I don't think its necessarily a size thing, although my OB was concerned I had GD because DD1 was 3.9kg. I don't - I just breed good sized bubbas!