Family remarks

So I need some advice. My mom and oldest sister are way overweight. And my 2 other sisters have been creeping up to the same thing. None of them do any sports at all, but I have been a runner. My body used to be very skinny but I started running therefore I have a big butt and big legs. My family always stares at me and whispers that I'm so much bigger now and that they're shocked at how I've become etc. It really hurts my feelings. Their opinion makes me strongly judge myself. Any advice?