Well, then why is everyone worried about what we eat now? Our bodies should just evolve to better handle the Big Macs, large fries and giant chocolate shakes.
The problem is that medical science is preventing that step in human evolution. If they keep on doing heart bypass operations to save people, then the genetic superiority of those who can survive "Super Sizing" their fast food meals cannot be exploited. However, if Hitlery takes over the country's medical system and drives it into the ground, people will no longer be able to survive their heart attacks.
Please look for my book "All I really needed to know about eugenics, I learned at McDonalds" coming to bookstores and drive-thrus near you.
Then, no question, I am an individually-wrapped, itty-bitty Snickers Bar. (Happens this time every year.)