Protein has become a popular nutrient with those looking to lose weight due to the popularity of low-carbohydrate and high-protein diets. While a diet high in protein can promote weight loss in its initial stages, a high-protein diet should not be followed for longer than three to four months.
What Is Protein?
Protein is comprised of 20 building blocks called amino acids. The body makes 11 out of the 20, called nonessential amino acids. The remaining nine amino acids, called essential amino acids, must be supplied to the body through food. There are two types of protein -- complete and incomplete. Complete proteins contain the nine essential amino acids and are found in animal and soy proteins. Plant proteins are incomplete but may be combined with other proteins to form a complete protein.
Function
Protein is one of three macronutrients that the body needs every day. As a macronutrient, protein may help curb your appetite, which can lead to weight loss. Carbohydrates and fats, the other two macronutrients, are used primarily as energy sources, while protein plays a role in growth and repair. Protein is found in every cell in the human body including the skin, muscles, organs and glands.
Initial Weight Loss
High-protein and low-carbohydrate diets such as Atkins promote fast weight loss by eating as many high-protein foods as possible. The initial weight loss on high-protein diets is from the loss of body fluids. Protein and carbohydrates help keep water in the cells, and on a high-protein diet there is a net loss of protein, which will draw water from the cells and out of the body. It takes a lot of water to expel the extra protein. Pulling water from the body will decrease body weight, but there is no effect on body fat.
Continued Weight Loss
After the initial weight loss on a high-protein diet, weight loss can continue. One way to lose weight long term is to reduce daily caloric intake. Protein acts as an appetite suppressant and controls hunger. Consuming high amounts of protein and controlling hunger can lead to eating fewer calories throughout the day.
Considerations
MayoClinic.com does not recommend a high-protein diet for longer than three to four months. Restricting carbohydrates can lead to nutritional deficiencies or insufficient fiber. This can lead to constipation and increase the risk for certain types of cancers. The risk for heart disease is greater on high-protein diets due to the high consumption of red meat and full-fat dairy. Also, high-protein diets can lead to liver and kidney damage because the body may have trouble eliminating all of the waste from breaking down all of the extra protein. Those with kidney or liver disease should talk with their doctors before beginning a high-protein diet.
Member Comments