How come I loose my appetite when I have my period?

When you say "...since I don't eat for the week...", are you seriously not eating for the entire week? I don't know if your period makes you nauseous or you just aren't hungry, but it's very important that you still make yourself eat something (hungry or not). I'm sure there are "diet drinks" that you can drink, that are used to be a full meal. I know my mom used to buy some that came in vanilla, chocolate, and strawberry..I think it was Slim Fast?