you seem misunderstand what i am trying to say. i am not complaining about being treated badly, but i am trying to present a model how we interact with each other.

maybe it helps to reverse the positions:

it is fine for me to compliment my friends on their achivements to loose weight because i know where they came from, but it is not acceptable to judge someone elses appearance because i don't know how it will be perceived. especially if it happens in public, congratulating someone on their body while not doing that on the nearby overweight person potentially makes that person uncomfortable.

likewise, receiving a compliment that i don't deserve makes me uncomfortable too.

we do need to consider how our messages are received. and with someone i don't know, i can't predict how that message is received, therefore it is better not to send the messsge in the first place.

if i do want to send a message i try to word it in such a way as to not be about them but about me: i would like to get my body in a shape like yours this removes any potential misunderstanding that i might generally favor people with a certain body shape, and it won't make other overweight people in the room feel bad.