How this diet works: 

There are numerous variations of the high-protein diet, but all recommend 30 to 40 percent of calories from protein. Foods that are high in carbohydrates, especially sugars, pasta, breads, cereals and potatoes, are limited. 

Good points:

Protein in foods can increase our feeling of fullness and satiety, leading to less hunger. Favorite protein foods such as steaks and hamburgers can be enjoyed without guilt. Lower-carbohydrate vegetables such as salad greens, carrots, tomatoes and broccoli are encouraged. 

Bad points:

Some high-protein plans limit carbohydrates to levels too low to promote health. Elimination of many bread and cereal products can decrease fiber in the diet and limit the consumption of many essential vitamins and phytochemicals. In addition, fat intake often increases, which may promote heart disease and some types of cancer. 

It is difficult when you go to restaurants and your intake alcohol or caffeine varies with each diet.  They are all impossible if you are a vegetarian. 

Duration: Indefinite