I had the same type of struggle....I would eat good day and night during the week and then overdo it with treats on the weekend. I think the key for me to avoid too much snacking at night is to make sure I eat when I need to during the day, and never get super hungry. I try to think of food more as fuel, and when I do need a snack I try to make smart choices.
Of course I've learned I cannot usually be trusted with eating from a bag, box, or container of anything so I make sure that I portion out my snacks. If you have a few multigrain crackers and low fat cheese with a few nuts on a small plate, you see how much you are eating and will see if it's too much or not. I sip on water or herbal tea (not too close to bedtime!), and also chew gum, pop a mint, or have a no added sugar popsicle when I feel the urge to snack out of boredom or habit.
I also wanted to suggest adding weight or body resistance training into your running schedule. Exercises that build muscle also helps to tone up and burn fat (plus it's good for bone health). I started training with russian kettlebells (iron ball with a handle), they call it the "broccoli of fitness"...it's not easy learning but I've lost an inch off my waist doing that type of exercise.
Keep in mind that sooo many factors influence the scale, so go more by your measurements, fitness progress and how your clothes feel. I know it's all easier said then done, as we all want to see the number on the scale go down...bur even if you can't see it right away know that by eating well and execising that all kinds of positive things are happening to your mind and body!