In many Latin cultures, just as an example, it's perfectly normal and common for families to assign nicknames based on body type eg height, weight (whether skinny or fat, tall or short). Its obviously affectionate in nature as well, but blatantly honest, when not used ironically (ie you might also ironically refer to a family/friend as 'gordo' who is very skinny). I say this as an overweight person myself (insulin resistance coupled with bad habits, full admittance there!).
In fact, I distinctly remember one Latin man I ever dated, who I could tell was obviously attracted to me, but once remarked to me very matter of factly 'you're a big woman'. I was in disbelief and confused at why he said it (it had genuinely not come up before) - i tutted, rolled my eyes and responded along the lines of 'yes, I'm aware, thanks for pointing out the obvious...' and he responded with 'no, i mean, even if you lost weight, you also have a big frame. Look at me I am very small, too small'. He didn't typically neg me or anything like that, when I look at the span of our time dating, in fact was very typically complimentary.
The reason I bring it this up, is the more Latin people I dated and met (and Italians, come to think of it, though to a lesser degree), the more I realised that within family, friends etc is it just the norm in some cultures, because people just aren't quite as sensitive to it. They can be very realistic and factual about themselves, and others. It isn't uncommon to discuss with both friends or dating partners exact heights and weights down to the cm and kg, even when you're both sat together and can obviously see!). In fact I distinctly remember another latin man i was dating, who had eyes in his head, could see, and after discussing height, proceeded to tell me his weight in kg and then ask mine! - then just move on to the next topic of conversation.
The point I'm making, is I do believe people need to build up a resilience to other peoples comments, and not everyone need shrink away under such comments. We as a society have become very sensitive to comments on appearance, and in many places and cultures in the world, it just isn't so.
This all being said, i also DO understand your point, because for me, personally, it's never entered my head to comment on peoples bodies or appearance, it just doesn't seem necessary. Plenty of people just do, and it can be shown as a sign of comfort and closeness with loved ones.