There's so much to unpack beyond these surface-level statistics, though. Like how there's some evidence that the health risks associated with increased BMI are partially an artifact of weight loss diets being really bad for your health, plus selection bias. People with lower BMIs are significantly less likely to attempt these health-destroying weight loss diets in the first place. Which would then imply that an approach to the issue that focuses primarily on how to get people who are already fat to lose weight, rather than as a prevention-focused public health initiative, may be doing more harm than good.

Or how lumping the overweight and obese groups together is a great example of lying with statistics by gerrymandering the BMI quantiles that seem to be healthiest together with those that have the poorest health outcomes, and away from a group that was arbitrarily defined the better part of two centuries ago based on one person's aesthetic standards rather than any health indicators, most of which weren't even known at the time. In other words, it's the crux of a pervasive piece of statistical circular reasoning.

And the moralizing statements like "normalization of the increasing status quo" that politicize the issue, thereby making it harder to have a nuanced, thoughtful discussion about the topic, and instead push it toward always being yet another pea shooting contest between the "personal responsibility" and "fat positivitiy" caucuses. Which only serves to drown out any attempt to really contend with the full magnitude of the nuances and unknowns that surround this issue.

This is nonsense. Obesity doesn’t cause health issues because of crash diets - the link between obesity and several bad health outcomes (insulin resistance/diabetes, hypertension, joint damage, to name a few) is extremely well established, and has nothing to do with diet and everything to do with the accumulation of superhuman levels of fat relative to the conditions in which humans evolved. You’re right that there is some controversy about where exactly the line for “overweight” should be, but there’s no question that when you get into the obese category (41% of Americans) it is extremely bad for your health, irrespective of what diet you’re on - humans simply aren’t designed to handle the amount of fat we now routinely accumulate.

> humans simply aren’t designed to handle the amount of fat we now routinely accumulate.

Maybe so, but like with all other evolution, presumably we'll either adapt or die?

Maybe fat accumulation via material prosperity is the Great Filter.

Yes, over the long term (tens of thousands of years?) evolution will probably come up with adaptations to material abundance assuming it lasts. Cold comfort to the people that suffer from it today though. Evolution can't do anything to help anyone who is alive today.

The link between many health issues and constant failed, and increasingly desperate attempts to lose weight is also extremely well established. Why do you dismiss the connection as if it were nothing in order to frame fatness as moral failure and disease as punishment?

> as nothing to do with diet and everything to do with the accumulation of superhuman levels of fat relative to the conditions in which humans evolved

This is a religious belief. Evolution doesn't visit judgement on human behavor, and any number of things that we do now that we didn't do in the Stone Age fail to have negative health consequences. Some might even be good for you, judging by the comparative lifespans of prehistoric humans and modern ones.

Look, if you care about people losing weight instead of wallowing in the cruelty and definitely something that looks like jealousy (e.g. that happy feeling some people get when they hear that people who have sex caught a venereal disease) - if you really care, then the health consequences of crash diets would concern you. The consequences of repeated failures to lose weight would concern you. None of this would be dismissed if your concern were health instead of moral superiority.

Sorry for the accusatory tone. To preempt, I'm 6', 175lb..

edit:

> Or how lumping the overweight and obese groups together is a great example of lying with statistics by gerrymandering the BMI quantiles

This is the fucking worst because it's conscious dishonesty. It's intentional deception.

I said nothing about the link between crash diets and health issues in my post. I only addressed this point in the OP:

> there's some evidence that the health risks associated with increased BMI are partially an artifact of weight loss diets

which is misleading at best - there is a huge amount of evidence that fat accumulation directly leads to health issues.

I am not moralizing in any way, I don't see anything in my original comment which indicated I'm passing moral judgement at all. I am simply stating that the health consequences of obesity are well known, and the causal direction is clear - obesity itself causes health problems. Again, I'm not passing judgement here - in fact I find the common refrain "eat less, move more" to be an extreme oversimplification of the problem, and I'm well aware that diet change is neither easy nor sufficient to solve the obesity problem. I'm just pushing back on the idea that crash diets are what cause the primary health issues associated with obesity - it's simply not true, and there's a mountain of evidence to back that up.

You have set up a false dichotomy. Why do you ignore that word "partially" in the sentence you quoted?

When someone proposes a partial cause, then pointing out the existence of other causes does absolutely nothing to challenge the premise that there might be multiple contributing factors.

This is not a particularly controversial idea among health researchers. I've been casually following obesity research for decades now, and one of the big themes I've seen is one of scientists being frustrated at their inability to get journalists and popularizers to give a proper accounting of the level of nuance in the knowledge we have. Your use of the phrase "the causal direction" implies that your knowledge is informed by these same popular sources that perennially frustrate the research community, because a proper accounting of the science does not permit the use of a definite pronoun in such a statement.

Because the magnitude of the effects isn't the same. The evidence is very clear - obesity _causes_ several negative health conditions. To suggest that crash dieting somehow reduces the relevance of those conditions is to deliberately mislead. Some links:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC380258/

https://pubmed.ncbi.nlm.nih.gov/33882682/

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5038894/

I would love to see any research you're aware of that would show evidence that crash diets cause significant health issues (I don't doubt that there are some diets that cause weight loss while being bad for health in other ways) but to suggest that the side effects of those diets compare in magnitude to the side effects of obesity itself is extremely misleading. If you have any reputable sources that provide evidence to the contrary I would be happy to read them, but I think you're misleading people, deliberately or inadvertently.

> there's some evidence that the health risks associated with increased BMI are partially an artifact [sic] of weight loss diets being really bad for your health

Citation needed.

Without fail when an article about health, weight loss and diet appears on hacker news these comments appear. Suggesting obesity isn't dangerous, and that we should be careful about addressing it due to normative standards, bias, demonisation etc.

In reality the severity of the impact of obesity on health is enormously underplayed in mass media - especially in the United States where are you admit there is a 'fat positivity' lobby.

There are lots of nuances around how and why this epidemic has happened. From food deserts to the promotion of fast food and high fructose corn syrup to shift work to sedentary lifestyles. But the impact itself is scientifically uncontroversial.

Sharing pragmatic articles about how to address this in our communities and our own lives is literally life saving.

I failed to find a citation in your own comment.

Not at all. The science is very clear and has been for quite some time - being overweight is bad for your health and increases all cause mortality.

I could link meta analyses about how strong the link between increased weight and CVD is as one example, but I don't think you're really looking to change your mind.

Instead I'll just make it as simple as possible. Increased weight = increased metabolic demand = more stress on the heart and other organs.

> I could link meta analyses about how strong the link between increased weight and CVD is as one example, but I don't think you're really looking to change your mind.

You could not say that you could do something if you don't plan to do it, and you could avoid blaming the person you're arguing with for your failure to produce evidence that supports your point instead. Try making it complicated.

your advice makes your own comment pretty ironic, don't you think?

but no. I really don't have to provide evidence that the sun is hot, that Washington D.C. is the capital of the United States, or that being fat is bad for you. I understand HN is for a technical audience, but in the nutritional and health field, this is an accepted fact.

> Being overweight and diabetes are comorbidities of nearly everything

https://www.independent.co.uk/life-style/health-and-families...

The only reason people treat statements like the ones you're making as obviously settled is because it plays into Protestant bullshit about being punished for enjoyment i.e. the worse it tastes the better it is for you.

The science of health vs fat is complicated, it's not some abstract moral tale of the gluttons being punished by god for their immoderate behavior.