A cop-out from what, exactly? Does society have a responsibility to make everyone thin?
Even if you say it does, how would you propose it goes about doing that? There's no scalable, organizable effort you can take that will make fat people thin.
If you say we have to throw more money at research, I say, sure, we should! Along with every other worthy cause. Where we're going to get the money, I've no idea. If you do, that's a completely different kind of argument.
Yet we don't tax sugar, processed food is the cheapest and non-processed are the most expensive.
The entire food industry is designed to sell more of 'their' product, and the addictiveness is developed more than the health value. Lobbyists ensure the governments keep the status quo.
While the libertarians might have a point that most such decisions turn out to be deleterious, it's certainly not the case that policy can't make you fat, and so can presumably avoid making you fatter.
Isn't that likely, though, that this research pays for itself?
But if obesity is primarily the fault of the person who is obese lacking will power then shouldn't we start by doing things directly addressing this.
For example, I snack late at night - except when there are no snacks in the house. Sometimes I'll still make food, but mainly I'll just wander around feeling tetchy and eventually get distracted enough to not think about it. For me it absolutely is lack of willpower (which is much better recently probably due to antidepressant meds) to avoid eating things I know aren't healthy for me; or indeed just to eat less in general.
If we're looking to prime cause then for me willpower seemingly fits the bill, as you say that revelation may not help to fix things for me - if I can do outdoor pursuits for a week then I can lose weight no problems! - but healthcare workers looking to help me should perhaps seek ways to enforce diet that don't rely on my willpower so much rather than just ignore willpower deficiency altogether?
Yes, we should. The average weight has gone up far faster than humans can change genetically, so people start looking for things like gut flora or epigenetics. Occam's razor would point to the average supermarket and restaurant selection of today versus a few generations ago to explain the obesity epidemic. Cheaper, faster, tastier food (capitalism optimizes for these three qualities in food), and more riveting, less active indoor pursuits can easily explain it. That's not to say the research is worthless, but gut biome most likely influences subconscious cravings, not BMR, and epigenetics is still young enough that many biologists think that pulling conclusions from research into it is premature at best.
This is a great analogy. "It's your fault" is not a public health policy, it's a cop-out. And it doesn't even make sense. Obesity is rising dramatically in developed countries. Is the current generation just morally inferior to the ones that came before?
Obesity is peoples' fault in the same way car accidents are. That doesn't mean the proper response is to simply blame people, instead of using science to devise solutions.