Well, if starving yourself is for self harm rather than a suicide attempt then, i'm glad because its a terrible way to die. If you don't want anyone to notice while living with a family, what i would do is instead of eating at the dinner table with the rest of the family, i'd just bring my meal to my room and flush it down the toilet, lol. There isn't any way of someone noticing that you haven't eaten in days unless you're showing it so i think you'll be fine. They might question you not eating with the rest of the family but there's nothing you can do. They won't try sending you to the doctor, at least. It won't be obvious at all that you're starving yourself. And what i would do (not everyones like me so this probably wouldn't work for you), i would drink water to make myself feel full because for me, water makes me lose my appetite for a few hours, especially if i drink it shortly after i wake up in the morning. If you're like me then this would be perfect for you.