[tsimionescu]

There is an alternative possibility: you start out with a metabolic disorder, that will eventually grow into diabetes. Along the way, it will make you obese and cause (directly or indirectly) heart and kidney problems.

Unfortunately, since Ozempic treats diabetes with or without obesity, and it also treats obesity without diabetes, it won't help us figure out if obseisty is a cause or a side effect of diabetes. But there really is little reason to pretend it's clear either way.

[phil21]

History is a pretty strong indication that it’s clear to me.

I find it exceptionally hard to believe populations at scale went from relatively “normal” weights to obese as the majority due to an emerging novel metabolic disorder. All within 1 to 2 generations.

Much simpler explanation is that diets and lifestyles changed leading towards obesity. Whether or not a metabolic disorder happened somewhere in the middle there seems irrelevant to me. It’s very clear to me that obesity causes the issues and not the other way around.

I’m open to thinking differently about it, I just find the evidence uncompelling as someone who was obese the majority of my adult life. Given the unique circumstances of how I grew up and then later experienced life, I’m quite confident obesity is primarily caused by lifestyle. Put simply - put yourself in a situation where obesity becomes easy to achieve and the majority of people will become obese.

Humans being what they are will of course have myriad of outliers to refute the point, but outliers are uninteresting to discuss in this context.

[tsimionescu]

The problem with this line is that there are populations that live very similar lifestyles but have massively different obesity rates. The rate on obesity in Tonga is much larger than the one in the USA, which is itself much larger than France - and yet all three are modern industrialized nations where the vast majority of the population lead mostly sedentary lifestyles.

Even within these places, there are often huge disparities in obesity rate. For example, Colorado has half the rate of obesity as the USA: are people in Colorado leading such hugely different lives from the rest of the nation? And are people in Colorado leading lifestyles more similar to those in California than those in Kentucky?

To me, the much more plausible explanation is that there is some aspect of modern life (most likely some element in our food, but very possibly in our enviroment as well) that is causing metabolic issues that lead to this huge increase in appetite that in turn leads almost inexorably to obesity.

[TrnsltLife]

Does altitude have an effect?

[phil21]

> are people in Colorado leading such hugely different lives from the rest of the nation?

Yes, absolutely. I've spent time in very obese locations in the midwest, and spent time living in Colorado and have relatives there.

The lifestyle differences are exceedingly stark. Drastic even. It's clowned on for the hippie/health conspiracy nutjobs meme for a reason. You immediately realize why people look different.

> And are people in Colorado leading lifestyles more similar to those in California than those in Kentucky?

Yup. Again, this is obvious simply from spending time in both locations. You will find places in CA that are nearly as obese as many places in KY, and find that the lifestyles look quite similar between the two. Louisville lifestyle is quite similar to Bakersfield for example and the obesity rate just so happens to coincide with that observation.

I don't know enough about Tonga vs. France to comment, but I imagine if you spent a few months living within the populations of both and living a typical lifestyle/eating a typical diet you'd likely find immediately obvious differences. In this case, genetics is also a very plausible front-line explanation - where in western countries it simply is not due to similar demographics changing so drastically over a generation or two while removing the immigration confounder.

> To me, the much more plausible explanation is that there is some aspect of modern life

Yeah, it's the diet combined with a relatively fast switch to sedentary lifestyles. Mostly the diet and food environment. Participation in adult casual sporting leagues and other outdoor activities is right behind it. Changes in the average activity levels while at work. Just 12,000 steps a day makes a drastic difference in weight for many people.

Technology plays a major role - screen time went from minutes a day to double-digit hours for the majority of the population. Hard to be active while staring at a screen of any sort.

Like I said - I'm also open to some environmental variable not explained by much simpler facts like the food environment, but I think that's exceedingly less likely than what is smack dab obviously right in front of our faces that for some reason we ignore in pursuit of near-conspiracy level stuff. The obvious thing usually ends up being true, and I see no reason in this case to believe otherwise.

Again though - exceptions abound. Humans are complex creatures. They average out quite well though at population scale.

[Aloha]

I'm T2D - I've come to believe obesity is a side effect of diabetes, if I'm not on my medications, I can fast for 2-3 days before my blood sugar comes down, because my liver is constantly pumping out glucose into my system.

There is no doubt that hyper processed foods make this condition more likely, but its not just "you have weak willpower and got fat and sick" - I know a ton of fat people who do not have and will likely will never develop T2D.