Weed.
I used to smoke weed a lot just for fun with friends, I stopped for a long time and smoked a little bit maybe every 6 months. I started have stomach problems a lot (No apetite, always nauseas, stuff like that) and I always feel sick almost 24/7. I went and grabbed a little bong for $45 from a local store, got some weed from someone who grows for medical purposes so I got some that mellows me out and makes me hungry. I shit you not, one little hit and I feel fine and can eat a bucket of food. It's crazy that it isn't 100% legal everywhere...