Here are several suggestions that may help you curb your afternoon cravings:

1. Plan your snacks in advance By planning what you will and will not eat, you are giving yourself permission to have a snack, but are making a controlled, healthy choice. Some good, filling snacks to try are fat free hummus dipped in home-made pita chips, this is delicious and filling. Other good choices are raw veggies, a piece of cheese and fruit, yogurt with a sprinkling of low fat granola, or air popped popcorn. By planning ahead, you can stop thinking about not eating, and look forward to your healthy snack.
2. Get out of the kitchen, or away from the vending machinesI found that if I could keep myself busy during the danger hours it helped immensely. I took up scrap booking during my weight loss year, a hobby I continue to this day. If crafting isn't for you, perhaps that time could be devoted to gardening, or running errands, or even taking a walk. Whatever works for you - just keep away from the food!
3. Try chewing gum or drinking a hot drinkSometimes, even after I had eaten my planned snack I found myself returning to the kitchen for a little something. Popping a piece of sugar free gum in my mouth helped remind me that I was done until dinner. Alternately, the act of preparing a hot drink also helped keep me occupied.
As you journey your way to good health, there will be the inevitable pitfalls and challenges. By facing each challenge as it comes, and logically planning how to overcome it, you can achieve your goals.
If afternoon snacking is causing you to stumble, try some of these suggestions to overcome the mid-afternoon munchies.