I quit smoking last August (smoked for almost 20 years)
instead of smoking I now have energy bars and nuts on my desk. (I have an iPhone to fill that empty "space" in my pocket where the pack of cigs used to live). Whenever I have the urge to smoke I snack on healthy foods (high fiber, high protein)
to counter this new "habit" I started hitting the gym every other day (hour weights, half hour cardio)
I dropped 30 pounds in about 2 months, I've since put about 10 pounds of lean muscle back on
I've never felt better in my life and my home and clothes no longer smell like ass (you start to realize that you smelled like ass once you've kicked for about a month)
I also feel less guilty about dropping $15 to $20 on high quality lunches (tuna, salmon, chicken, etc.) when I consider that $8-$10 of those dollars would have otherwise been (literally) burned into ashes.
there is NO cheating...once you decide you're done...you're done