I've tried a variety of sensible and not so sensible diet regimes, and the only one that works? Reasonable portion sizes of good food. Eat at home, not out. If you're going to be stuck "out" then pack a lunch or a snack so you won't be tempted until you get home to your good food. Take time to make your food so you appreciate it more.
Home made muffins don't have poly-whatsits or unsaturated-whosits in them, but you can bet the store-bought muffins do.