I wonder why a company cannot invent a version of white bread that has no calories or only minimal calories, sorta like sawdust. It would be filling but far fewer calories and no insulin spike either.
Large amounts of nondigestible carbohydrate tends to give people the runs. Actually fat too, that's one of the issues with e.g. Olestra
I’ve seen a number of low-carb breads sold in the frozen section of my local grocery store. They are closer to what you suggest. Also, I now wonder if they benefit from the freezing process in the way this study suggests.