Eh, that's normal human behaviour. I've found that if you're engaging in a behaviour that has a positive value judgement associated with it (dieting or eating

Eh, that's normal human behaviour. I've found that if you're engaging in a behaviour that has a positive value judgement associated with it (dieting or eating healthier, exercise, etc), if people find out and do not share that behaviour, it often puts them on the defensive (they're not doing it, too, therefore they are somehow lacking). This is exacerbated by the fact that a vocal subset of people engaging in those behaviours talk about it in order to either virtue signal or brag to others those who don't. After that it's all about protecting the ego. The vegetarian is seen as an inconvenience. The dieter is teased for not eating desert with everyone else. The people who don't go to the gym start explaining all the reasons why they hate gyms and the people in them. And I'm hardly immune. One of my friends is extremely fit and I caught myself teasing him about it as a consequence of my own envy and insecurities. I hope I've since stopped but it's a pretty basic human behaviour as far as I can tell.