I never noticed that in the zoo episode, but I am pretty oblivious most of the time.

I'm still always seeing new things and wondering how I ever noticed each rewatch.
I also have to agree with Sapphire, as a kid, I just didn't focus so heavily on some things that were plainly jokes and not really that bad overall.
While I think it was handled badly as an episode to focus on physical health, the gym episode, for example, I don't think it is wrong to promote being physically healthy and exercise and the jokes were kind of all on Usagi for being so obsessed and even gave a sort-of warning about these get fit quick schemes being dangerous to health. The creep way Jadeite made the sickly-looking girls feel good about their appearances after the pod treatment, for example. I'm pretty sure the intended audience (Japanese kids) were not hurt by it and took it for what it was, a cartoon...even in the 90s here I never heard of another kid being offended or damaged by it.
I'm not saying we shouldn't be sensitive to other people's feelings or be aware of harmful messages in media, (we should) I just think young people now are too hyperfocused on triggers, problematic themes, and such and it's causing them actual health and mental health issues.
This was not an issue in the 80s, 90s, and early 2000s. We played outside, we didn't have Twitter (thank goodness) and we learned to be good people without having to worry about being judged 24/7 by strangers we'll never meet but might ruin us online because they don't like us.
There was still racism, danger, bullying, and abuse back then, we dealt with it on a case-to-case basis and somehow survived.
We might have got into some different kinds of trouble back then (getting lost in the woods, scraped knees, and worse) but I think today's culture of bullies pretending to be some sort of moral authority is far scarier than anything back then and I don't envy kids who are on social media and live that crap daily. If I ever have kids (doubtful) I am not letting them on social media until they are adults. It's too toxic, damages their self-esteem, and is damaging actual growth for actual life.
I'm really beginning to see how the adults of my childhood felt saying "Back in my day..." they were right about some things and wrong about others.