If you feel like eating a "treat" (or buying one)... save on money and calories by treating yourself in other ways...
Set your hair, rub lotion on, do your nails, give yourself a pedi, give yourself a facial, go sit in the sun for a few minutes, run a bubble bath... whatever makes you feel good or feel pretty... have at it.
By the time you are done, you won't even want that pint of ice cream or new pair of shoes :)
This can also be a good way to adopt new habits that you want to incorporate into your healthy lifestyle... I mean, who puts on as much lotion, drinks as much water or cares for him or herself enough every day?