Every time I think I want to eat or drink something that is not positive for my weight, my diabetes or my high cholesterol condition, I stop and say, "I DON'T NEED THAT." Emphasis on the word NEED. Seems simple, but it works for me.
Instead, if I am home, I drink cold water with fresh lemon or lime squeeze. If I am out, I breathe deeply 6 counts in, 6 counts hold and 6 count slow release.