Are you suggesting that individuals have free will, choose the actions in their life and experience the consequences of their choices? Maybe smokers get lung cancer by chance and fat people just happen to die years earlier.  People are selfish. They want everything now and when disease appears they want a cure. "I have hypertension, give me a pill. I won't change anything, I want drugs. Why should I change anything?". The best thing about obesity is that it kills. It objectively is a trait that will die out we are watching evolutionary history unfold; enjoy the theatre.