People with low BMI aren't more active, they are just less hungry, 'run hotter'

Re:People with low BMI aren't more active, they are just les... by marifjeren on Friday July 15, 2022 @11:27AM (#32109119)

Of course it's no surprise that people who eat less weigh less. The surprise, I think, is that people who are underweight are relatively sedentary.

Maybe this is not that much of a surprise either though? I wonder how much of this has to do with muscle. BMI infamously ignores muscle mass. An interesting followup would be whether people with low body fat % are sedentary. My guess is that they aren't.

Side note: maybe there is a disparate importance of "Calories In" vs "Calories Out" for people who are under/over weight. Maybe underweight people should focus on exercise more, and overweight people should focus on eating less?

[ Parent | on HN ]

Re:People with low BMI aren't more active, they are just les... by rpmisms on Friday July 15, 2022 @11:28AM (#32109134)

I am mostly sedentary, and maintain body fat below 10%. It's mainly genetics, and probably 20% diet.

[ Parent | on HN ]

Re:People with low BMI aren't more active, they are just les... by gamblor956 on Friday July 15, 2022 @02:34PM (#32111368)

Sub-10% body fat is underwear model territory. At that low level of fat, every muscle is well-defined, no matter how small.

A lot of guys severely underestimate their body fat %. Sub 10% generally isn't possible without heavy dieting unless you're still going through puberty; genetics has nothing to do with it.

[ Parent | on HN ]

Re:People with low BMI aren't more active, they are just les... by rpmisms on Saturday July 16, 2022 @01:10AM (#32115403)

I'm aware of what it looks like, and I've been up at 12-15% before. It's absolutely genetic, most of my family runs very skinny. I have generally decent muscle definition, although the fat I have tends to sit in my hips and shoulders. My doctor suggested I might have less interstitial fat than most people, which explains a few other health effects.

I'm not bragging, there are serious downsides, but it's absolutely possible to sit at 10% year-round, just not while maintaining any serious level of elevated muscle mass.

[ Parent | on HN ]

Re:People with low BMI aren't more active, they are just les... by sovnade on Friday July 15, 2022 @02:04PM (#32111061)

and on top of that, it looks like there's other factors of diet than just choosing what to eat - it sounds like some people are just less hungry for indefinite reasons. genetics, gut biome, etc all probably play a part.

[ Parent | on HN ]