Why are some of us fat?

I always think about the God's strategy behind this. He could have easily made us all same as potatoes but no he had to create different shapes out of us - as shared by our fashion specialist-pear shape,apple shape...

After pondering on this question I came to a very interesting conclusion:
God has decided on quota of health and fitness He assigns to each human being depending on his performance in past life(me being a Hindu am firm believer of this).Now once this quota is decided it is subdivided into health and physical beauty.
So those who are physically beautiful with no serious health issues stand at the top of the list, and then slowly different fine percentage divisions are done which are too mathematical to be taken up here.
I for one stand some where in middle of this quota list so He could have made me slimmer but then He would have to give me a load of health problems to balance the total amount assigned to me so instead He made me fat and spared me of serious health issues.

The crux of the matter is God knows the Best,He knows what we need and He is least bothered about what we desire.I wish as parents we could also follow the same principle with our kids.