I think the most important thing is to make changes that you can LIVE with...not just for a few days or a couple of weeks, but long-term. Start with the changes that are easiest to make - diet soda instead of regular, or a splash of juice with sparkling water instead of all juice. Whole wheat (check the label!) bread instead of white - oatmeal or Cheerios instead of Fruit Loops. Start using extra virgin olive oil instead of butter where you can, and aim to incorporate more fruits and veggies in your daily diet. Try to have a little protein with each meal - this helps prevent hunger and makes meals/snacks more satisfying. I think it's also important to think about your personality - will you do better cutting certain things out of your life completely, or would you be better off adapting the way you eat certain foods to keep them in your new plan? Try to find healthier foods that you love - no one wants to live off of celery and sunflower seeds if they HATE those foods with a passion! There are so many great, healthy foods out there that you needn't suffer through menus you dislike.
It's SO important to realize that the weight won't fly off overnight - in fact, you really wouldn't want it to, 'cause then it's more likely to pile back on again!! Being patient with the process is key - perseverence and the ability to pick yourself right back up if you stumble are really important. You won't be perfect - no one is. But success comes when you keep going in spite of a pitfall.
