Hi C.---Fad diets do NOT work. The ONLY way to lose fat, and that is the goal, is to lose 2-3 lbs per week. When you go on a restricted calorie diet, your body goes into preservation mode because it thinks it is going to die. Without adequate fuel, the body does start to eat muscle, which is easier to get to than the fat. Your metabolic rate SLOWS in order to conserve the stores it has accumulated.
You MUST think of your diet as a way of life...not just something you do temporarily to lose weight. Of course, the easiest way to lose weight is to eat mostly plants...fruits, veggies, whole grains, legumes/beans, nuts and seeds. You want to eat as much volume of food as you can, while having that volume contain few calories...PLANTS. Look up the volumetrics diet on the internet. Another resource is the Vegetarian Starter Kit within www.pcrm.org. That whole website contains informaton that can help you with the resolve to eat mostly plants. For really great recipes, go to www.vegetariantimes.com.
Exercise is not negotiable. That will help you to lose weight faster and will help to increase your metabolic rate so that you burn more calories just sitting there. Use both cardio and weight training to encourage your body to achieve an optimal weight.
Many times people want/need to count something. I (and the health care professionals I work with) recommend counting fiber. Again, plants are high fiber foods and will keep you feeling fuller longer. Aim for at least 50 grams per day. Yes, 50 grams. We are woefully deficient in fiber, which is essential for intestinal health, as well as normalizing cholesterol and hormone levels in the bloodstream. And be kind to yourself. It is likely it took awhile to get where you are. It will take some time to get back to where you want to be.
I know I've thrown a lot at you in a short space. I am a wellness educator and I have access to a ton of great info for you, if you'd like it. Feel free to contact me at any time. Good luck...be well, D.