People too emotional. Sometimes good advice (whether it's said to you in a serious way or as a joke) is best for you to shape up. If you dont want to listen that's fine, but the core reason why people may poke fun is really because they want the best for you.
I dont think there are too many people seeing fat people hoping they are fat forever. If a fat person wants to be thin and a thin person could snap their finger and make them thin, I'm sure they'd help them out. They wouldnt say no and keep laughing.
I'm about 230 lbs. So I'm probably a good 50 lbs overwieght and it's been creeping up slowly. It's got to a point during covid I must had gained a touch because when I put on office shirts for the first time in 2 years, some of them are too snug. Oh well. I know that I'm not 300, 400, 500 lbs. But I get my jabs from friends and fam about being a fatty. Dont care. I laugh with them.
I used to wear nerdy glasses too starting in high school. Trust me. No trend setting cool glasses. Total blocky nerd glasses my parents picked for me sitting at the optician. Had my share of being made fun of geeky glasses. Dont care. In fact, looking back those big bulgy glasses have an advantage of bigger scope and visibility. For those of you who have never worn glasses, if you wear trendier slim lenses it's a pain in the ass playing sports because your peripheral vision isn't as good like wearing big lenses. When I got older and picked my own slick glasses, I'd purposely switch to my old frames (if the OS/OD were still good to use) for visibility playing softball or squash.