What happens if people do eat the indigestible leaves? They might not get any calories from it, but people have more than enough of those already in the develo

What happens if people do eat the indigestible leaves? They might not get any calories from it, but people have more than enough of those already in the developed world. What's the difference between a leaf full of cellulose and something like psyllium husks? Do people get nauseated if they have too many large pieces of leaves(I would imagine so, but I've never eaten random leaves so I don't know)? What about the various chemicals in them? There's gotta be at least chlorophyll and probably some other active stuff, right? What do those do if you eat them regularly? Are any of them beneficial?