I think if you live by the 80/20 rule and workout some what routinely you will be fine. I eat healthy 80% of the time but 20% of the time its PIZZA PIZZA!! lol
Honestly though I think the diet change I made that impacted me the most was about 2 years ago I stopped drinking anything but water. I drink a gallon a day (yes I'm the guy carrying the gallon around
). It seems to have worked wonders for me. I do cheat every once in a while and have a cocktail or a slurpee but I could count those cheats on one hand each year. Just got use to it and its a habit