I agree you should ask your vet. I just wanted to point out that there is some work involved with a low or non-pellet diet. I can only get this much green stuff for my bunnies this time of year, in the winter they must make do with commercially grown veggies and greens. To put them on a pellet-free diet during that time of year I wouldn’t risk and quite frankly, it would be very hard on my budget and I’d need another fridge to store all those greens in.
The pic above is of Yohio having a go at one of his daily helpings of greens. As you can see, he also eats a considerable amount of cardboard. I’m not sure about the nutritional value of that though. Probably just bulk.
My bunnies are voracious eaters, as most bunnies are. Both have tendencies towards plumpness, with unlimited greens and less pellets, they keep their weight fine, but then I give them so much greens that there’s always some left that wilt (and get thrown out), so I know they don’t starve. Plus they’ve hay 24/7 of course.