Well the tape worm is more of a long-term maintenance diet mechanism. It's part two of my program. (Part three involves kickbacks from the hospital.)
I try to avoid a cellulose diet though. If a cullulovorous gut microbiota developed, the gas would be awful. I have seen people marketing chitin pills (ground up crab shells) as a diet aid though. It's supposed to absorb dietary fats and pass them out through the stool. Those fishermen just have better marketing, I think.