I'm guessing not eating for three days at a time when I was in high school adversely affected my health?

Yeah, that wasn't cool. I'm an idiot, I probably screwed up my body irreversibly.
Answer:
I do not believe, that did anything to you.

Body has a reserve to take care of long fasting, which happened all the time during prehistoric times. Having three meals a day is some thing very new in human history.

---