I’m just pointing out that people have had to work in some capacity to live all throughout history. People would still need to work to live under any system.

Nobody said otherwise.

… the title in OP asked, “why do we live to work, rather than work to live?”

The response was “capitalism.”

So: precisely under (not-capitalism)… we could “work to live,” rather than “live to work.”

The same reason a bad person constantly talks about how they are a good person

A lot of the current health craze is related to the effects and aftermath of the covid pandemic.

Also I believe that the more people lose control of their lives and feel like society is in a downward spiral, the more they will try to hold on in the few ways that remain. What is one of those few ways: their own personal health and fitness. Not to mention that the gym is one of the only high profile “social”/shared spaces that remain, that are not just about shopping.

Some things are true simultaneously here:

• “Standard American diet” is very bad
• The protein recommendations coming out of health/fitness circles have been largely overblown, and are related to a fairly recent new marketing push

The problem with the SAD isn’t necessarily a lack of protein, although cutting out a lot of garbage food and replacing it with healthier food would in many cases increase protein intake (but not necessarily by * that *much)