Been listening to the paleo/primal podcasts lately and I absolutely love what Angelo Coppola says at at the start of his pod cast http://www.latestinpaleo.com/, Humans are not broken by design. We are not supposed to look like the fat dude on the end of the above cartoon, 1 in 3 women and 1 in 2 men are not supposed to get cancer (heard that on Dr Oz today who knows where he gets his facts though- point is still valid however, disease is rife in our world). Evolution and nature does have a certain amount of survival of the fittest at play, sure, but when people are getting sicker and fatter and not leaner and healthier something is wrong with this mechanism.
I believe it is down to two main factors; our diet and our health care. And if you want to get really deep just one factor really- greed. You see, we changed our diets to include excess amounts of sugars and these new things grains! The we get sick, we get these "neolithic agents of disease" (the going term). Then, our helpful doctors treat our symptoms with potions and lotions to mask up the disease- take diabetes for example: symptom is high or low blood sugar, "lets give them medicine to fix that and all will be well". I actually read an article (wish i had the link- will do better at that) where this doctor was suggesting that people with diabetes get more carbs than the average diet and then take pills to LOWER their blood sugar. You read right eat more sugar and then fix it with pills. Seriously! It is so concerning that this misinformation is out there.
When you follow the money however what do you find? Pharmaceutical companies with their hands in their pockets for just the types of foods that make you sick. Think about it, why aren't they putting their hands in their pockets for say, organic farmers or grass fed meat? Where is the advertising for healthy vegetables? So greed. Money. It is very sceptical to think this way, I know, but until you see someone up in their metal tower making a change for the health and well being of human beings, what else am I supposed to think? It would probably harm their stocks, don't want to upset the investors by deciding to save the world from eating itself to death. Besides we wouldn't sell as much medicine.