I would go more with, a lot of sad, fat kids at home, discovered the world of computers, where they could shine, because nobody cared how they looked in the real world, it only mattered what they could do. And this stereotype definitely still exists, I would be curious, how many of the HN crowd fit into it, but I can understand, that nobody wants to out himself like that.

edit: and I believe every fat person, knows and knew, that being fat is bad, but when you are sad and eating is your allmost only joy, what can you do? Starving and give up that little bit of happiness?

I don't have any higher education, I took the vocational school route for electronics and IT support, got a job and worked my way up through experience and various courses/certifications.

Maybe I'm a good example, because I used to be rather overweight (125+kg) and inactive. After I started working in IT, I've slimmed down to below 100kg and I've been doing crossfit for ~5 years.

A lot of us never did higher education, work in the industry, and still aren't fat.