[i_am_proteus]

Industrialization dramatically increases agricultural output, primarily due to use of fossil-fired tractors, harvesters, and irrigation pumps, along with fertilizers (which are either produced via industrial process such as Haber-Bosch, or are mined with the aid of industrial machines). Industrialization also enables sedentary lifestyles since humans are now examining computer screens and sheets of paper, and riding in steel vehicles on paved roads and rails, rather than labouring.

I have examined the author's claims concerning altitude. He presents a coloured map of the United States and makes the claim

`Obesity is less common at high altitudes because of the watershed.`

Yet his coloured map shows California (Most of the population lives near sea level. Even inland Sacramento sits at 46 feet.) as substantially less obese than the Appalachian states. His hypothesis is interesting but the evidence appears lacking.

[simiones]

People with sedentary lifestyles were common in the 1900s as well, well above the 1% of the population that suffered from obesity. People with sedentary lifestyles have also tended to have more access to food, again with no corresponding explosion in obesity.

Also, agricultural output is not directly related to human consumption, past some base. So again, there may be second order effects on known causes of obesity (food and exercise) but if those are already controlled for, we are only left with unknown factors.

Regarding altitude, they do mention in a future article that California seems to be an exception, but that may be explained by California's drinking water being in a separate watershed than surrounding states. I don't know enough geography to know if this is accurate or not.

Edit: here is the quote from III:

> It’s important to note that altitude itself doesn’t affect obesity directly. Instead, altitude is a proxy for how high an area is in the watershed, which is itself a proxy for how badly the local water supply is contaminated. This is why Mississippi is more obese than low-lying areas of California. In California the water supply hasn’t traveled nearly as far in its path to the ocean, and has traveled past fewer farms, highways, cities, and factories.

[three14]

I'm curious if there's good data on what constitutes a "sedentary lifestyle" over time. In the early 1900s, I suspect people with desk jobs had a lot of small activity over the course of the day that we can now avoid. I take an elevator, drive for errands, and look up just about anything without leaving my desk. I don't even have to cross the room to turn on the modern equivalent of the radio. I don't have to get anything from a filing cabinet except for perhaps a few times a year. Is that the same as "sedentary" of old?

[simiones]

That's an interesting observation and you may well be right that people in the past were more active in this way.

On the other hand, the contribution small levels of exercise (such as getting up from your desk and walking at a normal pace, even climbing a few flights of stairs a couple of times per day) to calorie consumption is likely to be almost nothing - a few dozens of kcal over the course of a day at best. I know that there have been studies for example of the additional kcal consumption from a standing desk compared to a normal desk, and the result is almost non-existent, less than 10 kcal over the course of a workday.

[three14]

The question is whether the small-scale activity has an impact on hunger, though. Very anecdotally, when I'm active, I have an easier time feeling full.

[i_am_proteus]

>Also, agricultural output is not directly related to human consumption, past some base.

Precisely. Prior to the widespread industrialization of United States farms, there were occasional famines in the United States. 1/3 to 1/2 of the country lived on farms and were engaged in farming. The industrial revolution freed us from the burden of physical labor, and provided plentiful food.

If California an exception, are Washington and Oregon also exceptions? Why does obesity not increase as one travels down the Mississippi? One would expect Louisiana (Mississippi delta) to be substantially worse than Kentucky (more mountainous and well-upstream of Louisiana) and Michigan (situated on the Great Lakes). Michigan and Louisiana are similar, and Kentucky is much worse. I refer to the author's data source.[0]

[0]https://www.cdc.gov/obesity/data/prevalence-maps.html#states

[simiones]

> The industrial revolution freed us from the burden of physical labor, and provided plentiful food.

Sure, but that happened well before WWII, while the obesity epidemic started sometime around 1970-1980 and is growing rapidly. The vast majority of the US population in 1950-60 had all the food that they could possibly want, and yet <1% of them were obese, versus 30% percent today.

> One would expect Louisiana (Mississippi delta) to be substantially worse than Kentucky (more mountainous and well-upstream of Louisiana) and Michigan (situated on the Great Lakes). Michigan and Louisiana are similar, and Kentucky is much worse.

I don't know enough US geography to be able to sustain this point one way or another. I will just mention that the CDC data is not the only piece of data the article uses to show this correlation between altitude and BMI, but leave it at that.

[i_am_proteus]

>Sure, but that happened well before WWII, while the obesity epidemic started sometime around 1970-1980

This is not correct. Mass-scale industrialization of US farms didn't start happening until the 1930s. Remember that it was the internal-combustion engine (not the steam engine) that permitted the use of tractors and other machinery to supplant human and animal labor.

Now consider that it takes time for humans to become obese. The children raised during the beginning of the massive agricultural surplus were precisely the ones who were fueling the start of the epidemic in the 1970s.