[loeg]

> The average American, both male and female, has more muscle mass than in 1924.

This is true, but sort of a sleight of hand -- obese people that don't exercise have more muscle mass than non-obese people who don't exercise, just to carry around all of the fat. And obviously the average American, both male and female, is more overweight/obese than in 1924.

(I agree with basically everything else you say, though.)

[bradarner]

Agreed, I was debating whether or not this was relevant to mention.

What I could have added was a caveat that sample non-obese people from each time would indicate that 2024 people have greater average muscle mass.

Personally, a more interesting question is whether growth along the Kardashev scale leads to a greater disparity in muscle mass vs body fat. The past 100 years would seem to indicate that it is possible. That being said, it could also be a uniquely American phenomenon. My hypothesis would be that avg muscle mass among French men has still grown over the past 100 years but I don't think obesity has grown to the extreme that it has in the USA.

[ido]

While the US is extrem, the “obesity epidemic” affects pretty much all countries as they become richer. I wonder if recent developments in obesity drugs like ozempic will have a significant impact there in the coming decades.

[loeg]

These obesity drugs are already having a huge effect -- obesity is down in the US for the first time in a long time (2023).

https://jamanetwork.com/journals/jama-health-forum/fullartic...

[amanaplanacanal]

I'm not gonna go try to find the numbers right now, but the Anglo speaking world is just ahead of the others. They are all trending the same way.

[pino999]

Obese people don't have more muscle, especially if you look into the more extreme cases. Muscle atrophy seems to happen due to low insuline sensitivity.

And relative they are weaker in the sense that the ratio between strength and body mass is smaller than that of normal people.

And then we have the powerlifting community.

[idiotsecant]

Have you never seen a fat guys calves?

[loeg]

So: extreme cases (both obesity and powerlifting) are not relevant when we're talking about population-wide averages. And relative weakness is also irrelevant (the original claim was solely about muscle mass -- if you want to talk about that being a bad metric, you're responding to the wrong comment).

You make one specific relevant claim: "obese people don't have more muscle." (Which belies everything I've read on the subject.) So, uh, why do you think that?

[danielbln]

40%[0] of the US population is considered obese. Pretty relevant to population wide averages.

[0] https://www.cdc.gov/nchs/products/databriefs/db508.htm

[loeg]

This is not responsive to my comment.

[oefnak]

It is. Read your own comment again.

[naveen99]

by that logic, women would have more muscle mass then men, because they carry around more fat. Average american by definition is average. Overweight by definition is above average. BMI normal is outdated, just needs to move up.

[JumpCrisscross]

> Overweight by definition is above average

Not true. Overweight and obese are defined on fixed scales. You can have a population that is 100% obese.

[loeg]

> by that logic, women would have more muscle mass then men, because they carry around more fat.

No? You have to compare like for like. Sedentary obese women have more muscle mass than sedentary normal-weight women, and sedentary obese men have more muscle mass than sedentary normal-weight men. (And the ratio of women to men hasn't moved very much since 1924, and both sexes are heavier than they were in 1924.)

The rest of your comment is not responsive to mine.

[strken]

Why would BMI need to move up? Because it doesn't represent the average, or because it doesn't represent health?

I think the former is uncontroversial but boring, and the later is wrong. I also think that people conflate the two because they want to pretend that being average is the same thing as being healthy.