The word dieting implies that you are restricting something for health reasons and no one wants to live a life of restriction. This not only includes the popular low-fat, low-carb, Atkins, Zone Diet, etc, but it also includes vegan, vegetarian, raw, and paleo.
The bottom line is that food restriction of any kind doesn’t work for people long term. Whatever behavior or plan you choose, it has to be something that you can maintain long-term. The key to long-term health and happiness, is building a lifestyle where you don’t have to give anything up and nothing is off limits—you just have to make everything better and upgrade the quality of your food and beverage choices.