Being fat is fine as long as you MOVE

[ergophobe]

Short version: a meta study found that "fit" people as defined by relative VO2max have roughly the same all cause and cardiovascular mortality regardless of whether they are "normal" weight, overweight or obese. Unfit people, by contrast, has much higher mortality rates, again independent of bodyweight.

https://www.physiologicallyspeaking.com/p/physiology-friday-281-fitness-matters

One quibble: if 74% of the US population is overweight, why is "normal" defined as "not overweight"? That seems like a poor understanding of "normal" and stupidly judgmental, especially given the findings of the study

[rcjordan]

I have a problem accepting "fit & fat".

[ergophobe]

Remember that they are measuring relative VO2max, which is relative to weight. In other words, if I'm a 50 and you're a 50 and I weigh 2X what you do, that means that I also have 2X the VO2 capacity.

Also, there are some questions I have
 - how was VO2max measured? In theory, this can only be measured with a metabolic cart, but in practice most of these studies use proxies like the Cooper Test (which measures how far you can go in 12 minutes). Some people say this matters. Some say it doesn't.

- how is obesity measured. If they are using BMI this is more of a problem. BMI will say a bodybuilder with 7% bodyfat is obese. In most surveys, this wouldn't matter that much because the number of people with high BMI and low bodyfat is low. The converse is not true, by the way - many people have low BMI and high bodyfat. So in this study, if you are looking at low-BMI people with low VO2max, you may be looking at very fat people who happen to be skinny and highly sedentary. Also, the number of people with high VO2max and high BMI might be athletes who are actually fairly lean at that BMI and have lots of muscle, good cardiac output and can put up big numbers in a Cooper Test.

Among those who would be considered obese by BMI (>30) would be a number of NFL running backs at the time of the NFL Combine (typically a time when they are highly trained and very fit).
https://www.reddit.com/r/DynastyFF/comments/t70ao6/bmi_and_speed_score_of_running_backs_at_the_nfl/

So those could be confounders.

At the same time, people who are skinny (that's a BMI number) can be fat (that's a DEXA scan number) and to some extent fat people can be relatively fit.

For example, marathoner and ultramarathoner Mirna Valerio is definitely high fat, not just high BMI and she's slow (11-13 minute miles; 6:13 for a marathon), but I would still guess that most Americans can not do a 50km trail run (as she has).
https://www.runnersworld.com/runners-stories/a21070665/ultra/

I would describe her as fairly fit and rather fat (5'7" and 250 pounds)

I was first introduced to this in high school by Covert Bailey's Fit or Fat book. He pointed out that people can be skinny (as measured by a tape for example) and yet be fat (as measured by % bodyfat) and that you can be very unfit and skinny or fairly fit and somewhat fat. My dad has fallen into that latter category since his late 30s probably. He could hike far, carry lots of weight, lift really heavy stuff, but he carried a fair bit of fat.