I am 25 w pregnant with my second child.

My first child was born only 6lbs and has grown up to be toddler in 18 percentile weight. He is a picky eater. This time around I am wishing if I have a baby that is more towards average weight...like in 50 percentile or so. So that she turns out to be eating well. I dont know if my theory will work but are there any foods or diet that result in a more healthy baby ? What are the pros and cons ?