If you eating a ketogenic, not being hungry is absolutely normal. That's why it is so effective for weight loss. Once you are in ketosis (and even more so when you keto adapt), you're body is fueling off of stored fat. So... even when you aren't eating off of the plate, your body is being feed through the food you have stored.
Other than that, fasting is quite healthy.
http://www.dietdoctor.com/member/courses/fung-fasting#1
I understand ED, but am unclear on what PCP is??