It’s actually a worse analogy if you understand the point be was trying to make.

In this scenario your engine turns diesel into used cooking oil at times.

The fact that the liver turns protein into carbohydrates (through a process that signals scarcity and arguably increases cortisol if relied on over time) completely dismantles his other overly simplistic argument that carbohydrates are poison. Our bodies make poison apparently. The logic is faulty UNLESS one has an autoimmune condition whose effects are worse than high cortisol, hair loss, suboptimal low testosterone, poor electrolytes absorption in some, etc. Otherwise, it’s kind of a larp and/or a strange lifestyle choice.