Protein belongs to a class of essential nutrients called macronutrients. You require large amounts of macronutrients in your body, and thus your diet. Protein is one of three nutrients that provide you with energy in the form of calories. In addition to providing energy, the protein you consume in your diet is vital for a number of other functions.
Functions
Protein provides structural support to all the tissues in your body. Protein also allows your body to build several different enzymes and hormones and ensures that your immune system can create antibodies, which help you fight off infections. Protein can also act as a transportation mechanism, helping carry substances throughout your body. The proteins in your body are also essential for helping you maintain acid-base balance and keeping the proper pH of your blood.
Protein Needs
You can calculate your protein needs in two ways. The first, more general way, is by calorie intake. Protein should comprise 10 to 35 percent of your daily calorie intake. Because protein provides 4 calories per gram, if you are on a 2,000-calorie per day diet, your protein needs range from 50 to 175 g per day.
The other way to calculate your protein needs is by your body weight. The Institute of Medicine recommends consuming 0.8 g protein for every kg of body weight. Using this formula, a 150-lb. or 68.2 kg, person, needs approximately 55 g protein per day.
Food Sources
The richest sources of dietary protein include meat, fish, poultry, dairy products, nuts and nut butters. You can also contribute to your protein needs through consumption of Greek yogurt, brown rice, broccoli and bran cereal. It is important to note that some types of protein are considered lean, while others contribute a high amount of saturated fat. When choosing protein, you should opt for skinless chicken, lean beef and low-fat dairy or fat-free dairy.
Considerations
A diet that contains too much protein has been associated with kidney stones, increased risk of osteoporosis and heart disease. Diets that do not contain enough protein, however, can lead to severe malnutrition and physical symptoms, such as dry skin, rashes, brittle hair and edema in the legs, feet and stomach. Most protein malnutrition occurs in developing countries or in poverty-stricken populations.
References
- "Nutrition and You"; Joan Salge Blake; 2008
- Harvard School of Public Health: Protein
Member Comments