Dr. Gregor is aligned nutritionally with Drs. Campbell, Barnard, Ornish, and the like, and with the Physicians Committee for Responsible Medicine. So his advice is likely based on a low-fat, plant-centric diet with little to no animal products.
As the author of the book, "Carbophobia: The Scary Truth about America's Low-Carb Craze," his blog will probably only appeal to a select group. After reading several of his recent blog posts though, his nutrition advice seems reasonable.