Should I just tell her I don't have appetite?

I plan on fasting today and then breaking it in the evening, I want to do this often because I want to be 120 lbs again, I'm 5''5 and currently 130 lbs. My mom would notice and tell me to eat but I'm not going to listen to her. Should I just tell her I don't have appetite? I don't want any drama or pressure to eat. I'm hungry right now but I want to endure.