I lost weight rapidly during a 2 week experiment of <20 grams/day carbs, zero alcohol, and 1600 cal/day total intake. Can't recal the exact number but even after the muscle glycogen was replenished, I was down over 5 lb. But by the end of the two weeks, I was so weak on the bike, I couldn't stand it. People were passing me on the commute! If I get desperate I might try that again and just be more zen on the bike.