Bullshit. This is just justification to excuse the supposed shame of being fat, and if you're not ashamed then you don't need this justification. Either way, the quote is pointless. And also insulting as it implies thin people have less personality.
You're not actually crazy, you're just very passionate. You want things to work out, you're loyal and care deeply about the people you care about. Passion is your superpower. Never turn down your powers.