When I read your post, the first thing that came to mind was "this sounds like my extended family!" I'm Asian and I think this is part of the Asian culture. Weight is EVERYTHING to these people. Growing up, my sis and I were always chubby and my cousins were skinny. They used to make a LOT of snide remarks about our weight. When I gained more weight in my teens, I remember my mom CONSTANTLY telling me to stop eating. Even if it was a snack, she would always say "You're going to put on weight!!" Don't get me wrong, I love my mom and I'm fortunate to have a good relationship with her. As far as weight loss is concerned, I do better when I'm not living at home. Like now, my husband and I will visit my parents once every 2 months and she has been telling me that I look smaller. She's been supportive of my diet because my sister and dad are also controlling portions (otherwise she stuffs us with food) so she cooks less.
I just wanted to give you support. I tried talking to my dad about his hurtful comments during my teenage years and his response was "deal with it or lose weight". Um. Ok.
Have you thought about moving out? Or limiting your contact with your mother and grandfather? I would suggest talking to them on a need-to-know basis. The minute the topic gets diverted to your weight, just leave the room (if it's not considered too disrespectful) or change the topic quickly. Keep changing it until they get the hint.
to you!