No Snacks, no sweets, no seconds. Except on Days that start with S. Too simple for you? Simple is why it works. Look here for questions, introductions, support, success stories.
I've said something similar here, only it was more like "if you're not hungry enough to eat an apple,..."
"That which we persist in doing becomes easier for us to do. Not that the nature of the thing itself has changed but our power to do it is increased." -- Ralph Waldo Emerson
"You are what you eat -- so don't be Fast, Easy, Cheap or Fake."
The biggest reason No-S makes such sense to me is that we were brought up on the same principles. My wonderful mom also used the "have a fruit" approach on us; nowadays the grandkids get the same treatment.
Our bodies are our gardens to which our wills are gardeners - Shakespeare