For me, it is all about "talking" to myself and having a mind set. For example.... we had dinner at my parents house on Sunday. We were celebrating my Dad's birthday. My mom told me in advance what we were having for dinner and I "told" myself what I could eat, before I even got to the dinner table. That way I wasn't faced with being hungry and having to make a quick decision. I told myself that I could have all the salad I wanted, one serving of lasagna, NO garlic bread, and a piece of birthday cake. And that is all I had (admittedly, the piece of cake was large!). If I had waited until I sat down, very hungry, at 1pm to decide about the foods and portions, it would have been very difficult to avoid the garlic bread. But it really didn't even occur to me to reach for a piece because I KNEW it was off limits and I was allowing myself a splurge on the cake, so I wasn't feeling deprived. BTW, the cake was DELICIOUS!! Mom tried a new recipe that was terrific and I don't usually like frosting ( a small blessing), but Mom tried a new kind and it was very yummy.
I do the same thing when confronting other food challenges. I am trying now to formulate a plan for Thanksgiving weekend. It is tough because we have two meals... we celebrate with DH's family on Thursday and then with my family on Friday, plus we spend the weekend with my folks because my brother and his family are usually up from the south visiting. It becomes a weekend eat-a-thon!
My Thanksgiving plan will probably involve me making a healthy non-guilty side dish and a low-point dessert (I'm on WW) for both Thursday and Friday and then working the rest of my food around that. The tough part at my SIL's house on Thursday is the large quantity of appetizers (usually 4-8 different types) and the ENORMOUS amount of food she makes... it is nothing for us to have 8+ side dishes in addition to the usual turkey, stuffing, potatoes. And everything is homemade, including things like butternut squash ravioli for a starter!! YIKES!!
Anyhow, you need to talk to yourself EVERY morning on your way to work and determine what you will have that day. If you tell yourself that you will ONLY eat what you bring in your lunch sack, hopefully that will help. Maybe you could start a small fund (piggy bank) on your desk or in your car. Everytime you DON'T spend $$ in the vending machine, put that amount of money in the bank. Try to save up for something fun like a new article of clothing (something really nice you want to buy when you reach your goal weight, like a leather coat), or put it in an account to save for a special vacation. I find that the financial aspect of not hitting the drive-thru or the vending machine actually more motivating than the weight issue! Maybe that is why I am cheap but not thin!!
Good luck jumpstarting your healthy lifestyle !..............................P