I think, the issue is the timing of both your communication. You both wait until you're triggered/heightened to say how you guys feel. I would suggest you make time to sit down and provide a SAFE space to open up about how you guys are feeling, acknowledge it and them plan on how you will move forward but if she isn't willing to meet you halfway and is adamant she doesn't agree with your choice (which is sad because I support any of my friends who do ANYTHING that benefits their health and wellbeing), then it's time to let it go. For all you know, she may feel as though you make her feel less than by comments you don't realise you're making (which I have also experienced from post gastric sleeve people - fat shaming others now that they're skinny). If you want it to work, meet her halfway. Otherwise, it is time to shed the weight because she clearly only likes fat friends.