Bloke that looks like a thumb

That's kind of like saying that epileptics just stand around starting at flashing lights too often. There are people who have bio-matabolic conditions that pre-dispose them to weight gain, sometimes to a high level. I realise that these people are in a minority, but they do have reasons, which are quite different from excuses.

Quite. And there are also mental health reasons, often serious. Further, a lot of people simply don't have the education to eat well, or there are other serious restrictions to their environment that just happen to cause them enormous difficulties. We all have our problems and we do not want them to be made fun of. How do you imagine this guy feels now that he's been splashed all over the Internet? I would hope that he's taking it positively as an incentive for action on weight loss, but you never know. There are very vulnerable people on whom this would have the opposite effect.

It's always very easy to just blame people, but in reality it's a lot more complex than just being 'their fault'. Top tip: Try to make the best case for a person first, and then you can perhaps judge their weaknesses, in that order (and they might just do you the same favour). It's called basic goodwill. Yes, people make mistakes, they often do really stupid things, but just don't be so self-righteous as to assume that there aren't sometimes important reasons that they can't overcome, at least not without help.