Many of us suffer from autism or anxiety or some other mental issue and hope to cure it with some strange diet. That's why despite being some of the most intelligent people on the internet people here will latch on to some singular model of human metabolism that's being promoted by the Russians or the Chinese right now (kidding, but only partly) and use it to justify a new "experiment".

Imposter syndrome fits in there. I didn't feel like I was good at my job or any of the things people think I'm good at, so I wanted to be this jack of all trades mad scientist character who uses himself as a guinea pig. Inevitably the low confidence leads to latching onto pseudoscientific theories -- it's a vicious cycle.

Others feel out of control of their lives and try to feel some sense of control through disordered eating (looking at you, "fasting"). I don't think I was really in this camp but I know people who are.