In your humble opinion, what should the human food plan/diet probably consist of for optimal health?

There are so many opinions and so much scientific data out there about what people really should and should not eat. Wheat-free, sugar-free, low fat, fat-free, no meat, low carb, no carb, no dairy, no animal products, lactose free, raw food, local food, high fiber, low fiber, enriched, the list goes on and on.

In your opinion, what would be the perfect, most nutritional food plan for humans? What would it consist of and what should be avoided.