Well if you grow tall it's not like you just get stretched out, but your width gets stretched out too. I am not saying there is a whole lot of different but if I had the waist I have at my 6'3 heght at 5'3 then I would be considered fat.
Can you imagine a guy 5'3 with a 36inch waist??? That's pretty fat, but not for 6'3.
-sk