I understand carb depleting for three days, followed by carb loading for three days at the end of a 12-16 week pre-contest diet in which you gradually lower your carbs throughout the diet, I've done it myself, but carb depleting for weeks? That's interesting.
So in the absence of the extra water and fiber that comes from carbs, wouldn't a no carb diet lead to constipation? Though fiber slows down food digestion, which is a good thing, water and fiber also help move food waste out of your body quickly. So even if you drink extra water and take fiber and vitamin/mineral supplements to compensate, isn't it bad for your body to carry all that rotting meat and fat inside longer?
Also, wouldn't going low or no carb for so long mess up your body so that the next time you go back to moderate carb you'll store more fat from carbs than you normally would, gaining all your weight back plus some?
The whole thing just sounds like a recipe for constipation, hemorrhoids, colon cancer and fluctuating obesity. Maybe some people are just built to live on a very low to no carb diet without consequences.