>(Anything above ~15% bodyfat in men has negative implications for lifespan, and ~30% for women; when reviewed at scale)

Can you link evidence for this? I stay at 12% year around as male (confirmed via DEXA)

▲

adam_arthur 7 hours ago | parent | next [-]

The claim comes from this study:

https://www.acpjournals.org/doi/pdf/10.7326/M15-1181

Though to be clear, there aren't a ton of studies that look at bodyfat percentage. Most use BMI and similar measures.

Likely overall fat levels matter more than %, I'd guess.

E.g. I'd presume being 15% at very muscular levels is less healthy than 15% at moderate.

(Because absolute fat mass plus visceral fat would be higher)

▲

Jweb_Guru 4 hours ago | parent | prev [-]

Sounds like absolute BS to me. Even in very large scale studies specifically designed for studying mortality, only morbid obesity has been negatively correlated with lifespan. There is even some evidence that being a little overweight is actually helpful for the very old (essentially, because it gives them more buffer if they get sick enough that they stop eating for a while). A lot of this is because modern medicine has gotten very good at treating stuff like diabetes and other stuff caused by obesity. Your quality of life will undoubtedly improve if you are thinner, but that's not the same thing.

▲

adam_arthur 3 hours ago | parent | next [-]

https://pubmed.ncbi.nlm.nih.gov/36756765/

Lowest risk is around 18-20 BMI in this recent study, which controls for many confounding factors not controlled for in other studies.

Other studies show slightly higher troughs, but often don't sufficiently control for correlation of weight with health in elderly people.

From this study: Estimates of mortality differences by body mass index (BMI) are likely biased by: (1) confounding bias from heterogeneity in body shape; (2) positive survival bias in high-BMI samples due to recent weight gain; and (3) negative survival bias in low-BMI samples due to recent weight loss

And if you follow the longevity/health space and studies as they come out, it's becoming pretty clear that bodyfat is objectively bad for you above a pretty low baseline.

It shows up in insulin resistance, heart markers, inflammation, and once you control for confounding factors sufficiently, mortality.

You likely won't become diabetic with a bodyfat of 25%, but all your health markers will be worse than somebody at 15%. This is measurable and clear.

	▲	IndySun 2 hours ago \| parent [-]
		BMI, in many cases, is considered a poor measure of health. https://www.sciencefocus.com/comment/bmi-we-know-its-flawed-...

▲

andsoitis 3 hours ago | parent | prev [-]

[dead]