I cut caffeine off about a week ago (going from a lot of sodas per day to zero), and had no issues. Even felt slightly better, and it seemed to help my natural sleep cycle, cause I can wake up earlier and feel better.

Then I tried to cut off sugary foods, and it has been HARD. Especially since there are always a lot of cookies at work, and a gas station within walking distance with lots of candy. But worse, I've had this hunger that won't get satisfied till I have a sugary drink or something.