Hi
I am not sure what and if you are on medication. I have experienced rapid weight loss it was related to meds. The combination of lithium, wellbutrin, & lamotragine resulted in loss of appetite. For the two years I was on the medication my family said it was painful to watch me eat. I would order a average sized meal and eat three mouthfuls, I was full.
If your loss of appetite began after taking medication go to your doctor, if he/she doesn't help you go to another. It took me 6 doctors before I found the help I needed, don't give up.
Cheers
Trina