What's "obesity related" mean, exactly?

I've realized I'm not entirely sure what the real meaning of that term is. It can be illuminating to check out genuine disease;

Some medical disorders have symptoms that mimic allergies or asthma. Some related conditions are extensions of allergic disease, and sometimes allergies or asthma can worsen symptoms of related diseases. The lack of an accurate diagnosis, treatment plan and coordinated care can leave you feeling miserable.

That's pretty clear. Some things have similar symptoms to asthma, some things tend to come in the wake of asthma and some of those can be worsened by the symptoms of asthma itself.

Some symptoms can be worsened by weight gain, some made lessened, alleviated or even delayed or avoided. Ditto slimness. It also varies individually in a way that's hard to assess in an objective gain/loss dichotomy.

I left the last sentence in for fun. Well, as much to show how the aim with genuine illness is almost always to reassure as anything.  Panic is not thought to serve real emergencies, more the creation of them.

In the days when I bought 'obesity' wallahs' spiel more or less, hook line and sinker. I assumed "obesity related" meant; take the amount of illness slimz have, from the amount fatz have and the product is "obesity related." So, if fat people had Y level of heart attacks and slim people X, then; X - Y = obesity related.

That seems kind of silly now, but, I didn't put any thought into it. My brain just manoeuvered there, given the information, then stopped. It was all on the reputation of those saying it really.

Then I took for granted fat people had more, though I knew enough to assume that it wasn't likely to be by much.

It was still odd even then, because, how would you know when a fat person had whatever condition because they were fat, when slim people also got the same conditions? Without a distinct difference how could you know whether that would have happened to that particular person, regardless of their weight? That or something else?

My mind worked out even then that because 'obesity' has no aetiology, it cannot be said to cause disease. Association is not the same as cause. Illness is more prevalent in Black people, working class people, women as opposed to men and vice versa etc.,

I put all this aside, it seemed not central to the issue at hand. But then, obesity wallahs hadn't got round to insisting on framing fat people as costs. They seemed to borrow from drugs charities who used costs of drug addiction to alert the people to the price of drug prohibition. 'Obesity' wallahs twisted, corrupted and mis-used that as they usually do.

In that context, more recently I realized it's often referring to the costs of treating type 2 diabetes an actual disease. So its an association of a condition which elevates risk of ill health; fat associated with type 2 diabetes = overall increased risk of morbidity.  My mind interpreted related as having a clear pathway to point that out. Which the complications and co-morbidities of diabetes have. Fatness does not.

It's like defining type 1 diabetes as slim related, because its more likely to appear (be apparent?) in slimmer people. If you compared that form in a slim person and a fat one, would you be able to tell whether being fatter would have meant the person avoided it?

The way that doesn't scan is kind of how people feel about relating illness to weight as a rule. Weight is a metabolic outcome, it can undoubtedly signal health to the good or ill. The problem is, it's usually too much part of an individual profile to be abstracted on its own.