>Modern day humans no longer trust the instincts they have developed over millions of years ... or what kind of foods to eat.

Really? This is a naturalistic fallacy. It's out precisely our instincts that cause us to overeat. As has been pointed out our instincts haven't adapted to the abundance and availability of food seen today. In an environment where food is scarce it is evolutionary advantageous to ensure your body had enough calories to make it until the next available meal. And this didn't mean picking the most nutritious food sources, we didn't have that luxury, it meant picking the most available. Only as directed by science do we now know what foods provide the most benefit or determent to our health.