I wonder how does the skinnies get dressed oversea: I wear European S which translate to XXS in the US, but there’s many people skinnier than me, still within a “normal" BMI. Do they have to find XXXS? Do they wear oversized clothes? Choosing trousers is way easier because the system of cm/inches of length+perimeter correspond to real values.
It's a crazy experience being just physically larger than most of the world. Especially when the size on the label carries some implicit shame/judgement. Like I'm skinny, I'm pretty much the lowest weight I can be and not look emaciated / worrying. But when shopping for a skirt in Asian sizes I was a 4XL, and usually an or L-2XL in European sizes. Having to shift my mental space that a US M is the "right" size for me was hard for many years. But like I guess this is how sizing was always kinda supposed to work.
The shame is inherent to the crushing expectations put on women's appearances and the pressure to be small. It manifests in clothing sizing for the same reason it manifests standing on a scale, it's a measure of your smallness. And what makes it insidious is that the measures are juuust comparable enough across different people to make people feel bad for not having the same numbers as someone 5" shorter than you.
And my experience isn't unique in any way here and it's really hard to not see it pervasive through our culture.
I worked at a Norwegian hospital once which had sizes from xxl (ekstra ekstra liten) to xxs (ekstra ekstra stor). So it's simple, you cross the ocean, you go from size xxl to xxs without having to do anything at all...
I should say though, that's the only place I've seen this particular localization.
For healthy adults, thirst is a perfectly adequate guide to hydration needs. Historically normal patterns of drinking - e.g. water with meals and a few cups of tea or coffee in between - are perfectly sufficient unless you're doing hard physical labour or spending long periods of time outdoors in hot weather. The modern American preoccupation with constantly drinking water is a peculiar cultural phenomenon with no scientific basis.