Obesity itself is poorly defined and the understanding of it has been determined by diet culture fads that affect the directions nutritional science goes, in a co-production feedback loop. Medicalizing adiposity is fraught with socioeconomic issues. Best to let people live and wear what they like.
When I worked at a big box store for years I wasn’t allowed to wear my BLM shirt or anything “political” but my Trumper coworkers got away with wearing their Trump shirts or Let’s Go Brandon shirts, and they even put Let’s Go Brandon stickers up all aroubd the employee facing areas. If you told managers about it they addressed it as a dress code violation and regarded you as a snitch.