It's based on the government "science" that fat is bad and carbs are good. Check "Fathead", a pamphlet made by a libertarian showing the BS on this ridiculous science.
Ever since I watched it, I completely cut grain (but still eat it when there's nothing else, like on a trip) and I've never felt better. What more, EVERY SINGLE blood stats (cholesterol, triglyceride, etc) have improved during those 7 years.