My parents don’t care..

One thing i‘ve noticed and that’s been very upsetting for me is that my parents don’t care when i barely eat anything. Just because they know i‘ve been trying to loose weight now for one year they don’t care how much i eat. But is it normal that i‘ve been struggling with food and my weight over a year now, non stop??? I don’t think so because it’s been so so hard for me... okay so yesterday i only had one meal because i binged the day before and my parents asked me if i had any food and i told them that i didn’t and they said nothing about that BUT my sister lost her appetite since a few days and my parents are going crazy since. Like they are constantly checking on her and they want to force her to eat AND they wanted her to go and see a doctor. And everything just because she is not trying to loose weight. And just because i am trying to loose weight, that is okay not to care about me?? This isn’t fair..