I watch a lot, a lot of videos, presentation etc on the subject of diet and health, but nowadays I am fairly discriminately when choosing to watch or not, as I am completely on message. However, occasionally a gem emerges. This is one such, and one I am watching again.
As links don't always work, go to the tube and look for:
Dr. José Carlos Souto - 'Low-carb: myths that refuse to die'