I have lost 20 pounds in 12 weeks. I sleep great. My anxiety is gone. I am almost never hungry or feel like I am starving myself. I have tons of energy and feel great. I eat healthy and have had only a small amount of sugar in the last 12 weeks.
I don't think 20 carbs a day is necessary to keep me feeling this way, but after 6 weeks you don't have to stay at 20 carbs a day. Most people do 50-60 carbs to maintain.