DIETS DO NOT WORK. Period.
The diet industry makes BILLIONS of dollars off of the fact that people are so impatient and insecure- do not be another ignorant sheep, listening to their false claims! Don't buy into that crap, seriously! And don't waste your money! (Read the fine print on advertisements- what does it always say? "Results not typical. Results occur with proper diet and exercise." WELL DUH!) How crazy is it that, according to different clinical studies, 75-90% of women have disordered eating? Do you really want to be a statistic?!
So, you ask, what DOES work? Well first, I would recommend therapy in order to work on self-esteem and body image issues. I mean, come on, do you really want to spend your days OBSESSED with dieting instead of living? Second, as we've heard over and over, exercise and proper intuitive eating helps a lot. This means seeing a professional dietitian, with a Bachelor's degree of Science in dietetics, who can figure out a meal plan catered directly to YOUR needs. This means being honest about your exercise (whether a little or a lot), your medication (that you NEED- this doesn't mean taking appetite suppressants and crap), and your mental/physical health.
Lastly, remember to appreciate the body you DO have. I know you've heard it over and over, but no one has the same body- some have small frames and others have large frames, but in the end, you can't change your bone structure, people! Manipulating your healthy weight/"ideal" weight to be lower than it should be equates to asking for hormones/steroids to make you taller, or asking a doctor to chop your legs off so you can weigh less/be shorter. If you are spiritual, consider verses like Ephesians 2:10 and 1 Samuel 16:7- go to the Bible NOW and read these, and you'll see why the media's obsession with looks/weight is totally bunk. I recommend, as I have done, writing out a thank you letter to each part of your body. Example: "Thighs, I am so thankful for you because you allow me to rise out of bed every morning and do chores. Without your muscles and fat, I could not do this."
But yes, re-think your obsession with dieting. DIETS DO NOT WORK.
Living your life DOES.