Sometimes, people are not ready to confront their own demons, and there is not much (in my opinion) you can be doing other than what you are to emphasize, "My weight loss should not effect our friendship!" You are not trying to play it up and act arrogant, but demurely thank people for the congratulations and go on your way. Maybe your new lifestyle is too much for them right now, but they may come back around. Keep up the excellent weight loss and try to keep up your positive attitude. What you are doing is amazing!