I was on he Trail for 6 days, so not too long. I lost my appetite though, the heat and fatigue I think, so was really only drinking water and electrolytes (the water had to be purified for a couple hours prior to drinking). I ate some trail mix and a little rice and steamed leaves that the locals made, a banana here and there. So I lost weight.

I was in reasonable shape I guess but the Trail is pretty brutal. Elevation map below.

https://en.wikipedia.org/wiki/Owen_Stanley_Range