Dr. Berg is not a researcher himself, and my impression is that he is sometimes operating on the basis of outdated studies.
I prefer to listen to the primary researchers in the field. Stephen D. Phinney, M.D., Ph.D.; Jeff S. Volek, R.D., Ph.D.; Richard D. Feinman, Ph.D.; Thomas Seyfried, Ph.D.; Uffe Ravnskov, Ph.D.; Robert Lustig, M.D., Ph.D.; Eric Westman, M.D.; Benjamin Bikman, Ph.D.; Grant Schofield, Ph.D.; Catherine Crofts, Ph.D.; and many others.
The science journalists, Gary Taubes and Nina Teicholz are also known for the quality of their voluminously-documented surveys of the field of nutrition research.