My office always has free donuts and cookies in the break room. I keep away from them by 1. always bringing my own snacks so that I'm not hungry enough to go for a donut and 2. remembering how crappy I feel after I eat donuts. I always get a sugar rush, followed by a stomach ache/headache, and then of course I feel guilty for eating a ball of sugar and oil. I know that my good choices lead to more good choices, and poor choices lead to worse choices. if I go a whole day without even thinking about a donut, my reward is how great my body feels and the pride of a job well done.