Hi ! Good eveining. I am Dr Shareef answering your query. Steroids are one of the first line drug therapy for auto immune encephalitis. This no doubt causes a gain in body weight in long term use. Whether you can go for any other kind of treatment or not could be judged by your treating doctor. Therefore, I would suggest you to discuss this frankly with your doctor who is well aware of your clinical condition. I hope this information would help you in discussing with your family physician/treating doctor in further management of your problem. Please do not hesitate to ask in case of any further doubts. Thanks for choosing health care magic to clear doubts on your health problems. Wishing you an early recovery. Dr Shareef.