Its really hurtful when your own family members always feel the need to comment on your body. It has happened to me as well since I was a child. When I was a teenager I gained weight (I guess because of hormones) and my mom gave me hell for it every day (I didn't even used to eat that much, and I did sports), and my grandma told me when I was only 15 that I should go on a diet. Then at 18 I lost all the weight and suddenly I was "too thin" and "should eat more" even my parents wanted to take me to the doctor and control me in the bathroom just in case I had bulimia because I ate a lot but never gain weight.
Then at 27 I started lifting weights at the gym and some people (not my mom, because she does too) told me I shouldn't do that because I would look like a guy (which never happened).
People are never happy with how you look, they always have something to say. The best thing is to ignore them and just do what you want, but when it's your own family they can really hurt you and even lead to trauma.