Hmmmm, they moved close to you not "In with you". Why are they interfacing with you at meal times when you have your own place. Maybe you need to enforce meal time boundaries as in meal times are at your place alone & not with them. Maybe an occasional weekend meal together but you need your own space.

Also a boundary of no discussing weight. Why are you talking to them about weight loss or gain anyway.....it is none of their business. You seem to struggle with setting boundaries specifically in this case with your family.

Are you in therapy? Maybe ask your T to help you with this issue.