How do we fight purchasing what the store wants us to purchase? I have 5 rules that are a fail-safe every time:
1. Always shop only from your list. 
When you have taken the time to put your purchases to paper and made that commitment, your mind is less likely to be distracted. You will be as the arrow flying to its target with no external forces altering your course.
2. Always shop the outside aisles of the store first.
When you are there with your list, and your list reflects the 70% fruits & vegetables, 15% proteins, 1-5% carbohydrates and 10% healthy fat meal plan, 90% of your purchases will be found on the outside aisles. Start with the vegetable section, move to the meat section, then to the dairy, and finally to the legume section, there you have it, your entire shopping trip. If you are vegan, it is even easier, go to the vegetable section, then find your tofu and vegetable broth and finally legumes. No chance of distraction.
3. Shop the specials before you go. Usually the in-store deals are an attempt to get rid of expired product. Go online, print the specials and ignore all other input. Not only will you save a TON of money, those cheap high carbohydrate sales will stay on the shelf.
4. Eat before you go shopping.
If you are hungry when you shop, don’t you find your shopping cart is twice as full? Hunger is the most brutal of all distractions. Suddenly the deli looks great, ice cream looks better and for the end, just as you are about to get check out and leave the store, you’re standing in the checkout line and that candy bar all of a sudden is drawing you in--you can’t seem to stop your thoughts and then your hand reaching for it. Take time to eat before you shop, it will change your point of view and keep you from succumbing to those “special deals”.
5. Plan your treat for you and your family. If you already know what your healthy treat is going to be before you go shopping, you will not be tempted by the cheap offering to offset the stores profit margin and thus injure your health. The desire of your eyes will lead to the pleadings of the heart, and the heart can be treacherous. It is so much easier to prevent and conquer before you leave.
There you have it, 5 steps to success. Give it a try and you will be successful. A closing question: We tend to plan everything in our lives, vacations, bills, schedules, school and the list goes on, why not schedule your shopping so as to enjoy it that much more?