The most important thing by far when you diet is for you to be able to change. Of course, this means you have to change the amount you eat and probably what you've been eating as well. It undoubtedly means too that you have to mend your errant ways and stay on your diet all the way to your goal, and then maintain an eating style that will keep the weight off.
But this is not all. You also have to change some central things about yourself. There are all kinds of thngs that fall under this change-yourself, non-food category. For instance, you may have to change some of your thinking, your feelings, your frustration tolerance, your level of assertiveness, your sensitivity to the comments of others, perhaps even how you look at love. Oh, there are so many possible things you could change that aren't food and eating, aren't dieting, aren't exercising to lose weight. They are all things that are personal and unique to you, and it's always a tall order to change these. That's why losing weight and keeping the weight off permanently are so hard to accomplish.
Here's the good news. What do you have to have before you make these personal changes? Do you have to be willing to withstand a certain amount of discomfort? Do you have to be ready and able to confront personal issues? What about being willing to make a big effort? Do you need to have hope that these changes are attainable? Do you need to have a positive attitude? It's great when you have any or all of these abilities before you start. The good news is that you don't really need any of them before you start. You can pick them up along the way.
If you can believe, really believe that diet and weight loss success come from personal changes as well as eating changes, this in itself is a remarkable personal change, an important shift in how you think about weight loss and you.