Like walking into a bank wearing a suit and a good haircut vs ragged jeans and long hair. It’s also a big weakness of humans that they dole out trust this way, but it makes all the sense in the world that we do so.

I think one of the most remarkable demonstrations of this I know of is a study I remember seeing referenced somewhere (maybe "Influence" by Cialdini) that showed that people are more likely to cross a road on a red light if someone in a suit crosses it first.

Can you please elaborate a bit? What differences did you notice?

Having been through this myself, my own experience:

Going from being ignored in nightclubs, and have people tap my shoulder if they needed to get past, to having people instead slide their hands over my pecs or stomach or pat them to get past (both men and women suddenly started doing that), getting my butt pinched half a dozen times a night, and having half a bunch of random strangers who also lifted weights want to high five me for no reason.

I'd never had women pick me up in nightclub before, as opposed to having to be the one to approach. Afterwards I did. I had random women want to make out with me within minutes of meeting on many occasions. Of course not all of that is necessarily down to the change in my appearance - it's very possible some of it was also down to my increased self confidence, but either way the difference was massive.

Looks and confidence are of course by no means the only things, but it's a multiplier, and you can up that multiplier significantly by lifting weights.

I was pretty attractive in high school. The most startling example of this I ever experienced was sitting at a table playing yugioh with only traditionally "nerdy" looking guys, and a girl came by and said "do you know how unattractive playing that game is?" and then she looked at me and said "except you, it's cute when you do it". It truly is a completely night and day experience in how you're treated, negative things about you become cute and quirky and you can do no wrong in many people's eyes.

When he was obese, people were like, ugh a fat slug who needs to stop eating 2000 calories a sitting. plus his nose is kinda crooked. When he got fit, all the sudden he started looking a pretty sexy guy who's got it together. that slightly crooked nose? now a cute quirk that makes his face more unique and charming.