I am blessed with that low muscle insertion calves genetics, so I never need to train my calves. My calves grow even just by walking a lot, but you'll notice that a lot of fat people have huge calves as well.

I've been wondering, does feet size also plays a role in the size of your calves? I have a friend who has about the same height and size as me (186cm 100kg), but he wears US 9 shoes while I wear US13 shoes, and his calves are tiny compared to mine. He used to be obese as well and his calves were small then.