I read recently

A snippet of the linked article stands out. One Michael Edelman, weighing 1200 lb at his heaviest, in the end made serious attempts to lose weight. My emphasis:

After the sudden death of Walter Hudson [another notably fat person], with whom he had formed a long-distance friendship, Michael developed a pathological fear of eating. He rapidly lost several hundred pounds, taking nourishment only when spoon fed. At about 600 lbs, he literally starved to death.

Now, it's clear from that article that all of these people ate massive amounts, but then, one has to ask why they did that. Just what are the causal connections here? What are the causal arrows going into the "overeating" node? To say "gluttony" is just giving a name to one's ignorance and mistaking it for knowledge. What actually distinguishes someone to whom a triple chocolate muffin with chocolate sauce and a chocolate-coated chocolate flake on top with extra chocolate is a temptation to be resisted, from someone to whom it is not a temptation?

What other arrows are going into the "obese" node? What arrows are coming out of it and where do they point?

I don't think anyone knows the answers to these questions.