Difficult workout followed by insatiable hunger

This doesn't happen often but has a few times. Today was one of those.

I was out for what was a short run this evening just to get in some miles. The distance was only 2 miles, nothing challenging at all for me to do. I was running a very familiar path beside a river, so mostly flat. 71 degrees, 55% humidity. I typically run 5-7 days a week. Been exercising for years and while I'm not in a competitive time of life now, I've been a successful local age group racer.

I run by effort and only a couple of times a run look at my watch. Effort today was to be easy. Today, I was feeling sluggish from the start. At the turnaround, I noted that my average pace was about 45 second per mile slower than it should be. On the way back, I guess I'd say I was lightheaded a bit and I definitely could tell I had a little tunnel vision. I finally stopped a bit to rest until that went away and ran back home.

Once I got home, I had hunger that was insatiable. Literally I felt I had to eat. I also drank 2 glasses of water, but I had a craving to eat I could not ignore. Wound up eating a tangerine, slice of bread with jelly, olives, sweet potato chips, and spoonful of peanut butter. Truthfully, there was not way I could avoid the urge.

Anybody had anything like this happen to them? Over the past 10 years it has happened to me maybe 5 times or so. But it is very disconcerting. Any ideas what happened?