Delhi Police said Wangchuk was hospitalised on medical advice and in compliance with High Court directions after his health deteriorated during the fast.
Congress and the AAP accused the Centre of suppressing democratic protest, while the BJP said the government acted only to safeguard Wangchuk's life.
AISA members remained on hunger strike and Cockroach Janta Party (CJP) founder Abhijeet Dipke announced he would begin fasting.