Well, there are spiritual contexts and every area has a different one. Ever gone through a city and it just seemed dark, but you can't put your finger on it? Or whenever you're in one place you have little no no motivation? Or certain areas where you're more easily annoyed that normal?

So, it might be the food, as that also makes a difference, but it might also be the spiritual context of the wear you're in.

Having left for a while and then come back, will usually make these things more obvious, as you've had a break from them for a while.