When eating, your body burns calories just by digesting, absorbing, transporting, and storing the food.  For the body to break down protein, it will require a 30 percent expenditure of energy, which is the highest of all the macronutrients.  Therefore, if you eat 100 calories of protein, 30 of those calories will be used to digest the food (burning more calories than fat, as stated below).  Therefore, there would only be 70 calories left that the body would have to deal with.

Other Diets (High Fat and High Carbohydrate)

This is the reason why diets that are high in lean protein tend to reduce more fat mass from the body than other weight loss diets, such as high-carbohydrate or high fat.  In contrast, the body only uses 2-3% energy expenditure to digest fats.  As such, a gram of fat has more than 2 times the calories of a gram of protein.  Research has shown that high-protein diets make the individual feel fuller after eating due to the reasons stated above.  When you are full, it is likely that you will eat less.  In this sense, consuming protein-rich foods can help an overweight or obese individual lose weight.

Natural Weight Loss Strategy

Eating protein-rich foods (preferably lean meat, nuts, dairy products, tofu, and soy) also stimulates the release of weight loss hormones in the body.  These hormones help to regulate hunger.  Protein is also needed for building and maintaining muscle.  Muscle is important for weight loss in that having more muscle increases your body’s metabolism.  It has been estimated by a study published in the American Journal of Clinical Nutrition that for every 22 pound difference in lean body mass, the body will burn an extra 100 calories a day.  As a result, you gain more muscle and your body will burn more fat.

Source: http://www.alive.com/7780a20a2.php?current_topic=35

Author Bio: Jessica Bouchard is a Nutritionist for Camp Shane, the country’s leading and longest-running summer weight loss camp for children. With locations in New York and Arizona, Camp Shane teaches children how to develop and maintain a healthy lifestyle on their weight loss journey.