I will have to add a few things to your message. Although I believe a person can prevent many diseases by eating healthy and taking care of their bodies, as you say, there is a higher authority, but this is were we disagree. My higher authority is God. He is the one who chooses what child a couple is going to have. And He is the one who puts the soul in that child, not the child him/herself. So God may have different plans than ours. Usually, He does expect from us to take care of our bodies, which in the bible is mentioned as "the temple of the Holy Spirit" (to those who are christians). So God has His plans, but at the same time we are responsible to take care of ourselves.