While they work, they don't teach the individual anything about healthy eating. Once the person is off the "diet", they gain the weight right back. I think the best plan is one that can be followed until the day you die...in other words, it wouldn't be classified as a diet, but rather a lifestyle change. Cut out crap, cut out all the terrible carbs, cut out the liquid calories, cut out bad snacking. Learn to cook healthy and delicious meals.

But I get the allure of shedding the weight quickly. It's just so hard to stay on that type of a diet long-term.