this is just a cultural thing

It is, but I feel like this is so misunderstood.

The cultural part isn't really about not minding comments on appearance . It's about hierarchies and it being rude to disrupt the "harmony" by doing anything but laughing and agreeing.

When Granny calls you fat, everyone should laugh. Let her know how her hair is thinning and see how the turn tables. Don't let Uncle know that we can see he is combing his hair with discount shoe polish so "no one" knows he's going gray.

Little Meimei is so cute when she's a chubby toddler. Everyone gives her sweets. Then one day she's too fat and the same aunties and uncles who overfed her are making snide comments about how she'll never attract a good man.

They don't disregard the comments.