I read somewhere once that when in a food dilemma between eating something you should eat and something you shouldn't eat (but really want to), a person never regrets the healthy choice. But the unhealthy choice - it's only a matter of time before the regret comes. 5 minutes, an hour, a day, 5 seconds!!! It will eventually happen.
I must say I find that to be 100% true. If you have knowledge of the good and the bad that you choose to put in your body, the regret will eventually come. It always does.
Bleh. Regret is a terrible feeling, no matter what it's over.