I think there are many healthy ways to eat. I like the ideas put forth in Blue Zones (a book about people who live much longer than average and what they eat). I also think the Whole30/Paleo people are onto something with "It starts with Food."

It's easy to agree on things that everyone should probably limit - highly processed grains, sugar, processed fats. If you are shopping the perimeter of the grocery store, you are probably doing just fine.