I can't eat without it either, first thing I do when I wake up is light up. It's because it has an effect on ghrelin which is an appetite stimulating hormone, I don't make any without cannabis at this point I guess.
There's various stuff you can take to induce appetite, if you want to turn to medication that is. I did, but I'm still on the weed so eh, I don't know if it works as well. Various (cortico)steroids induce appetite the same way, I bought some ibutamoren as it's perfect for that, but haven't tried it yet. Prednisone is another example and a lot more easily available, but also antipsychotics or some early tricyclic anti-depressants. Anti-histamines or calcium channel blockers like gabapentin and pregabalin work too and might be a bit more recreational, but maybe not as functional.
It all doesn't work as fast as the weed though, that's light up, finish whatever you're smoking and 5 mins later you're ready to eat, almost. Yeah I don't know.