It is much easier to say no to junk food snacks and fast food if you don't let yourself get to the "starving" point. Make sure you eat small snacks in between your meals and never let yourself get overly hungry. Your brain does not think rationally when your blood sugar drops and your stomach is growling like a monster, and all you want is junk food. Keep this from happening by snacking on a regular basis and it becomes much easier to make the right choices.
Sometimes we put in all the effort: count those calories, eat low carbs, low fat, ramp up the exercise, drink the water...and the scales don't budge. Don't get disheartened, remember it's about the journey not just the destination. Scales are only part of our healthy lifestyle...feeling good about the positive efforts we've made is worth it's weight in gold. Keep on keeping on.