[Evgeny]

Yes. The only way the carbs are stored in the human body is in the form of glycogen, in liver and skeletal muscle. There's about 1 kg of it in total, maybe a bit more if you're a trained athlete. And glycogen binds about, maybe, up to 3 times as much water by weight. So, altogether, about 4 kg.

After switching to keto, glycogen is used up gradually, due to no carbs entering the body. And the water is also lost. Therefore, the "signing bonus" of the keto diet - a significant weight loss in the beginning, but due to water lost, not fat burned.

BUT. That only accounts for about 4 kilos, maybe just a bit more. You can't really blame water for a gain of 20 pounds.

Am I missing something?

[freehunter]

No one ever said it could account for 20 lbs. Merely that you should expect weight loss when you're cutting carbs and weight gain when you reintroduce carbs.