He doesn't know how but he knows he loses weight by dieting and exercise, link bait title.
Furthermore, what he describes is a typical low-carb diet which works by suppressing your immune system (my experience with a low-carb diet, and the experiences of most people I know who have done a low-carb diet for long enough). After burning all your fat, you will get sick as hell (I had a 1 month fever at my lowest weight before deciding to stop it).
People with great metabolism can be fine on low-carb. But if you're seriously overweight, your metabolism is probably not great.
Slow carb diet by Tim Ferriss is a bit better because you ingest more carbs (and the cheating day maintain your immune system).
If you have cold feets/hands, inflammation (swollen gums for example), bloating, slow pulse, low libido or anything not normal, then your diet is not the right one.