Mahaprabhu Nitayananda took sannyasa at an early age. As per the Sri Sri Chaitanya-Bhagavata, the first authentic biography of Sri Chaitanya by Srila Vrindavana Das Thakura, Sri Advaita Acharya says Nityananda Mahaprabhu lovingly:
matsya khay mansa khay kemata sannyasi/...tare boli sannyasi ye kichu naahi chhay/bolaye sannyasi dine tinbar khay// (Madhya-KhaNda, Chapter 24).
Meaning : You eat fish! You eat meat! How are you a sannyasin? A sannyasin should eat food once in a day, but you claim to be one and eat thrice.
Was Mahaprabhu Nityananda a non-vegeterian?