Protein is an important component of every cell in the body. Proteins are comprised of hundreds or thousands of smaller units called amino acids (20 in number), which are attached to one another in long chains. The amino acids can be arranged in millions of different ways to make each unique protein.
The role of proteins in the body is for growth and maintenance of tissues, carry out biochemical reactions in the cell, act as messengers i.e. hormones, provide structure and support for cell and transports and stores nutrients such as vitamins and minerals. Since protein is essential for growth and maintenance of tissues, adequate intake of protein is particularly required during periods of rapid growth such as childhood, adolescence, pregnancy and breastfeeding. Our bodies do not have a reservoir for proteins like it does for carbohydrates and fats, hence daily adequate intake of protein coupled with adequate energy intake is important.
Dietary Protein & Managing Diabetes
Protein does not have much of an effect on blood glucose levels. Individuals with diabetes and normal renal function should have 15% to 25% (1-1.75 g/kg body weight) protein contributing to their daily total caloric intake. This is similar to the protein requirements for the general population. However, for individuals with diabetes and early kidney disease, the protein content should contribute 10 – 15% (0.8-1 g/kg body weight) of their daily total caloric intake, while those with later stages of Chronic Kidney Disease should have <10% (0.8g/kg body weight) protein contributing to their daily total caloric intake. This is to minimize the pressure on the kidneys since it plays the key role in eliminating protein waste (excess protein) from the body.
Quality of dietary protein
- Higher biological value vs low biological value protein.
Proteins are made up of amino acids. There is a total of 20 amino acids. Amino acids are classified as either essential/indispensable or non-essential. Essential or Indispensable amino acids cannot be produced by the body and hence must be provided by diet whereas non-essential amino acids can be produced by the body and hence do not need to come from the diet. When a protein contains the essential amino acids in the right proportions required by humans, it is termed a high biological value protein. When the presence of one or more essential amino acids is insufficient, the protein is termed a low biological value protein. Hence the quality of protein is determined by the types and proportions of amino acids that it contains. Generally, proteins from animal sources have a higher biological value, and digestibility, than proteins from plant sources. Though high in biological value, animal proteins also come packed with saturated fat and cholesterol, which are known risk factors for heart disease. For this reason, balancing one’s intake of animal and plant proteins is important (50:50).
- Appropriate proportions of animal and plant sources proteins in nutrition
An ideal diet should consist of both animal and plant-source foods in appropriate amounts and proportions to ensure intake of sufficient quantity and quality of proteins, while consuming adequate dietary fiber. It is good to aim for a diet whose total protein is comprised of approximately 50% high biological value/animal protein and approximately 50% Low Biological value/Plant protein. Let the animal protein be comprised more of fish and poultry (without skin) and less of red meat (pork, beef, lamb, mutton) to minimize our intake of saturated fats and maximize our intake of polyunsaturated fats.
Animal based protein
Fish and seafood
Try to include fish at least 2 times per week.
- Fish high in omega-3 fatty acids like tuna, herring, mackerel, trout, sardines, and salmon
- Other fish including catfish, cod, flounder, haddock, halibut, silver cyprinid (omena) and tilapia
- Shellfish including clams, crab, shellfish, lobster, scallops, shrimp, oysters.
Poultry and eggs
Choose poultry without the skin for less saturated fat and cholesterol.
- Chicken, turkey
- Eggs – Due to high cholesterol content, limit intake to a total of 6 in a week.
Beef, pork, veal, lamb
It’s best to limit intake of red meat which is often higher in saturated fat. If you decide to have these, choose the leanest options, which are:
- Select or choice grades of beef trimmed of fat including: chuck, rib, rump roast, round, sirloin, cubed, flank, porterhouse, T-bone steak, tenderloin
- Lamb: chop, leg, or roast
- Veal: loin chop or roast
- Pork: center loin chop, ham, tenderloin
It is also important to limit your intake of processed meats like ham, bacon and hot dogs which are often higher in saturated fat and sodium.
Plant-based protein foods provide protein, healthy fats, and fiber. They have been found to control blood glucose in both diabetic and non-diabetic patients. Try and mix up different plant sources of proteins in your diet to make up for the essential amino acids that might be missing in one plant source but present in another. Plant protein sources are also largely comprised of carbohydrates and so should be taken with regard to our recommended total carbohydrate intake. Findings showed that increased consumption of these types of proteins reduced:
- Fasting blood sugar level
- Insulin resistance and increase its effectiveness
- HbA1C readings
- Beans such as black, kidney, and pinto
- Bean products like baked beans and refried beans
- Hummus and falafel
- Lentils such as brown, green, or yellow peas; green grams; yellow grams; chana dhal.
- Peas such as black-eyed or split peas or chick peas
- Soy nuts
- Nuts and spreads like almond butter, cashew butter, or peanut butter
- Tempeh, tofu