In addition to carbohydrate, our bodies also need dietary protein to stay healthy. Protein is used in the body to promote the growth, maintenance and repair of body tissues, to help the immune system fight off unhealthy bacteria, to promote wound healing, and to provide fluid balance within our body tissues.
Protein can be used by the body for energy; it supplies 4 calories per gram. Protein is not, however, the desired fuel for the body. It us used for energy when our intake of carbohydrate and fat is low.
Protein also takes longer than carbohydrate to be broken down and turned into sugar, therefore, it doesn't have as great an impact on blood glucose levels.
Types of Protein
Protein is made up of building blocks called amino acids. There are 22 amino acids, 9 of which are essential amino acids, that is, they must be obtained from the diet because our bodies can't make them. In order to be recognized by the body as a complete protein, a single food or a mixture of foods must contain all 9 of the essential amino acids.
Sources of complete protein include meat, poultry, fish, dairy products and legumes (beans, such as kidney beans, lima beans and navy beans). Plant protein (except legumes) are incomplete proteins, by themselves, they do not contain all 9 essential amino acids. If you do not eat animal products, you can get all of the essential amino acids your body needs by eating legumes or by consuming a wide variety of plant-based foods.
Protein Content of Foods
Animal-origin foods have greater quantities of protein compared to plant-based foods. Foods from the protein category provide the body with B vitamins and zinc which are necessary for normal digestion of the foods we eat, iron which helps to supply oxygen throughout the body and magnesium which helps relax muscles after contraction, plays a role in nerve impulses, is involved in helping certain minerals to be absorbed into the body and keeps teeth and bones healthy. The protein content of selected foods is as follows:
|Meat, poultry, fish, legumes||7 grams per ounce
|Legumes||7 grams per cup
|Soybeans||14 grams per cup
|Milk||8 grams per cup
|Breads, cereals, rice, pasta||3 grams per serving*
|Vegetables||2 grams per cup
|*a serving is generally 1 cup or 1 slice of bread
How Much Protein Do I Need?
If you are healthy and do not have kidney disease, the American Diabetes Association suggests that you eat 2-3 servings of protein per day. Each of these servings should contain 2-3 oz. of protein. A 3 oz. portion of meat is about the size of a deck of cards. In order for the protein to be absorbed best, it is important that you divide it into at least 2 servings and not combine it into 1(4-6oz.) serving.
Because protein is harder for the kidneys to process, when damage occurs to the kidneys it is necessary to limit the amount of protein in the diet. If you have kidney disease, ask your dietitian about how much protein to include in your daily intake.
Effect of Protein on Blood Glucose
When protein is eaten along with carbohydrate containing foods, the carbohydrate foods do not raise the blood sugars as high. So, instead of eating a baked potato alone, add some cheese or a piece of baked chicken on the side.
Some people have noticed increased blood sugar levels when a much larger than usual serving of protein (9 oz. or greater) is eaten. But generally, a person can get away with eating a bit more fish, poultry, meat or cheese than usual and not have it affect their blood sugar nearly as much as if they'd eaten more carbohydrate than usual.