I know this is a controversial topic especially on here but I do believe there’s some truth to it.
It could be (bad) gutbacteria steering your son towards it because they need it to thrive on it,hence why he doesn’t look that healthy because of it.
It could be the PUFAS in peanut,the starch,maybe molds…..specific kinds of gutcritters crave different kinds of foodsources.
My guess is that it migth be the PUFAS. Josh Rubin has done an older video on it.