LET ME BREAK THIS DOWN FOR YOU...
I have learned plenty during my lifelong ride on the diet roller coaster. I still have not managed to get off the fucking ride. But that will be changing in 14 pounds.
There is no magic pill or miracle diet. Hate to break it to you, but all of that is worthless and temporary. You have to make a lifestyle change. You need to be aware of what you are eating and remember you have to feel satified & not full. Let's not forget that exercise is key. If you starve and not exercise... you will be gross and saggy!
For gals... make sure you have a low fat, low carb and low calorie diet. The lowest amount of caloric intake recommended by a doctor is 1,200 calories a day. For guys its 1,800 (if I remember correctly). Don't waste your calories by drinking them! Drink water or diet drinks. Make sure you stick to whole grains, lean meats, low fat dairy, veggies & fruits. You can get creative and make some really tasty stuff.
I highly recommend the biggest loser work out DVDs. I love them! They are fun and make you sweat like crazy. Its very inspirational to see the contestants of the show in the video. Some of the videos even include workout and nutrition tips (recipes) . They have 4 different DVDs. The DVDs mostly have a bunch of short workouts that you can combine however you want. You should do at least 30-45 minute workouts 3 times a week. It goes by quick and you will feel great once it gets easier and easier. If you have a gym membership, make sure to sculpt along with your cardio. Muscle is a hot plate for melting fat. The more (lean) muscle you form, more calories are burned.
I've done a lot of those wacky diets. I've done Jenny Craig, Cabbage Soup Diet, Atkins, Nicole's Diet (400-600 calories a day with no exercise) blah blah Nothing has worked best and had me feeling great like what I described above. Over the last 6 years I've been on the damn coaster. I estimate that I have lost 106 pounds from my peak weight about 6 years ago. I love to help with this crap... so feel free to ask if you'd like.
I agree with all of this except the low fat dairy and diet drinks.
If you need them for some reason, fine. Better to be healthy and eating processed things than to be overweight (I say the same thing to people who eat sugar free deserts and such... better to just not eat desert... but if you NEED them...). But in the long run, the less processing done to your food the better. Diet drinks and low fat dairy (and this includes dairy derivatives like salad dressings) are frequently heavily processed to obtain the results without the usual fat requirements (for example, without fat, sour cream is not creamy, so you don't get ranch dressing without it, etc).
Dairy fat is largely healthy fat. It contains a ton of the protiens you need for your muscles to work efficiently. You will rarely find a runner or other casual athlete who would touch low-fat products. In fact, Cottage Cheese is so popular with athletes because of the high concentration of good protiens in the fat.
Diet sodas are even worse for you. They are full of chemicals and syrups and preservatives and god knows what else. Again, if you need them, go for it. But you're much better off with water.
Note: this doesn't include low-fat dairy things that are just made with like 2% milk or whatever. Some dairy products can be made with 2%, which is just whole milk + water (not tap water, it's some of the byproduct of the dairy process, but same idea).
I've found that eating healthy, fresh, natural (unprocessed) things AUTOMATICALLY causes you to consume fewer calories. Let me give you an example... a cheeseburger you buy at Burger King could easily have 1000 calories in it. But if you make one yourself with half lean ground beef and half turkey, a whole wheat bun and whatever condiments you like, I guarantee you that you save yourself 200+ calories. Now, an 800 calorie cheeseburger is still not good for you, but if you changed nothing else about your diet except that you'd be losing 10 pounds a year.