As I understand it, the current medical consensus is that fat protects muscle, and has health benefits when it is in moderation, but increases risks for bad outcomes when in excess. And muscle weighs more than fat, and aside from heart disease, generally protects against death of all causes. If muscle is generally good, and fat is good in moderation, why do we still popularly conflate skinniness as healthiness?



You dramatically overestimate the number of people who can bench their bodyweight, forget about 2 plates. Your highschool were people in their prime, I bet those 7 did not maintain their fitness through the following 3 decades. And as I said that’s a starting point for considering whether BMI breaks down for an individual, it’s not a definitive statement.
BMI is just a tool for assessing whether there is cause for concern. Like a screening when a physician asks how many drinks you have a week. An answer of 10 doesn’t make you an alcoholic, but they’ll ask some follow up questions.
Similarly a BMI of 30 doesn’t produce an OMG reaction and pressure to get bariatric surgery. But it will drive a lifestyle conversation. And I can guarantee any physician who sees that result and and sees you’re built like a brick shit house will not be recommending food restriction.
The BMI standards were established in a healthier baseline population than currently exists. The 1940s and 1950s had a higher proportion of manual labor than we have now. So those arguments fall apart.