It takes a deficit of about 3500 calories to lose 1lb. Let’s say you stop eating at all for those 60 days. Assuming you burn 2500 calories a day idle, then after 60 days you’d have burned 150,000 calories, which would lose you ~43 lbs. Also your metabolism would slow down if you stopped eating and would make you lose less.

I don’t think it’s possible without some kind of surgery, but that violates your requirement of not spending a lot.