Yes, Americans are fat, the average adult male is 200lb and the average height is 5'9 [0]. They'd be less so if everyone could squat their own weight, especially if that was in addition to the bar itself.

Europeans are a bit lighter, about 10 pounds on average [1]. Sounds like we could all stand to lose weight before taking up lifting.

[0] https://www.cdc.gov/nchs/fastats/body-measurements.htm

[1] https://en.wikipedia.org/wiki/Human_body_weight

You don’t need to loose weight before taking up lifting. Just adjust your expectations.