It's hard when it comes from family members, but I think its inevitable because every family and circle of friends has "that a**h***". If they're the kind of person the judge someone for the weight loss, they were already judging before the weight loss. Take pride in knowing that you live rent free in their head tormenting them
As for you, just keep up the good work! People who haven't experienced it don't realize the work that is still required, nor the pain/discomfort that is experienced in the weight loss surgery process. Especially for people who's metabolism is just naturally geared toward not eating much or staying small. To them, they falsely believe that since it is so hard for them to gain weight by forcing themselves to eat more, then you must have voluntarily forced yourself to be overweight. They don't realize how foolish that concept sounds because they've never walked in your shoes. If they don't choose to make the effort to understand, they never will.
It is hard brushing it off from people that are close, but as I mentioned earlier about living rent free in others' minds, don't let them dwell in your head. Evict them and go on about your day!