Perhaps the best diet plan is one that actually incorporates parts of other diet plans to create a balance where the other separate plans usually stress overeating one type of food while not eating enough of another type of food. Low-carbohydrate diets are an example of this.
The other side of the coin from the so called omission diets are those which encourage excess in a particular foodstuff - the high protein diet being a prime example. The main aspect of this regime is that adherents are encouraged to gorge themselves on high protein foods and avoid those high in carbohydrates and other substances.