Dietary protein has been a topic of question for the last several years. Many individuals struggle to understand what adequate sources of dietary protein are and how much of these sources should be eaten. Protein represents an incredibly important component of a healthy, balanced diet. As such, it’s imperative to understand protein’s role in the body as well as what and how much of it to consume.
The Myths About Protein
When the Atkin’s diet (low carb, high protein), first became popular over 20 years ago, several misconceptions about protein emerged. One of the first of these myths is that consuming high quantities of protein and low quantities of carbohydrates is the best method to lose weight. While many individuals have found short-term weight-loss with a high protein, low carbohydrate diet, there is little research supporting that individuals have been able to keep the weight off long term. Concerning weight loss, it’s very likely that individuals on the Atkin’s diet or other high protein/low carb diet found themselves consuming fewer calories than previous, thus losing weight more rapidly. As you would imagine, if these individuals were unable to make changes to their lifestyle eating habits, once they stopped the diet, it’s very likely they put the weight back on.
Another myth is that the human body requires a large amount of protein to function effectively. This is also untrue. Protein is not used for energy, and while it is a necessary component, it’s not required in large amounts. In fact,consuming too much protein can be detrimental to health.
What is protein?
The human body is comprised of billions of proteins. Muscles represent protein and bones are simply protein with calcium. Each cell in the body contains protein structures and even antibodies are proteins. Proteins are complex compounds varying in size and shape.
Amino acids represent the building blocks of proteins. Of the over twenty amino acids, only ten are essential components of the diet. These ten include Alanine, Asparagine, Aspartic acid, Cysteine, Glutamic acid, Glutamine, Glycine, Proline, Serine and Tyrosine.
The human body has a remarkable ability to recognize its own proteins while rejecting outside proteins. When the body consumes protein in the diet, it is first broken down into amino acids prior to its absorption and use in creating new proteins.
Protein, unlike fat, is not stored for the body’s future use. Body muscle can be used by the body to create other proteins. Protein is an essential component of the daily diet and surprisingly, the need for protein is not significantly altered by activity level. Contrary to popular belief, protein is not used for energy. Individuals requiring the highest amount of protein or those who are pregnancy or currently growing.
Sources of Protein
There are numerous sources of protein, however, studies indicated that 75% of protein in the food supply is provided by animal products. Animal products include foods like meat (beef, pork, and lamb), poultry (chicken, turkey) and fish. Foods like eggs, milk and cheese also represent protein containing animal products. There are also many non-animal, protein rich foods. Legumes like beans (black, pinto, kidney, etc.) and peas represent a great source of plant-based protein. Tofu and other similar soy products also contain protein. Nuts and seeds are another source of plant-based protein. Small amounts of protein can be found in some grains, fruits, and vegetables.
There are two types of protein. A food that can provide all of the essential amino acids is known as a complete protein source. All animal-based foods are complete protein sources (fish, meat, poultry, eggs, cheese, and milk). An incomplete protein source represents a food that is low in at least one or more of the essential amino acids. Complementary proteins occur when two or more incomplete protein sources are combined to provide all of the required amounts of the essential amino acids.
Because protein is widely found, it’s unusual for individuals consuming a varied diet, to become protein deficient. However, those who don’t eat a healthful, varied diet may be at risk. Individuals consuming diets heavy in processed junk foods (chips, cheese puffs, processed cakes, etc.), may find themselves protein deficient. As long as an individual consumes a varied, healthful diet, protein deficiency is avoidable and rare.
Plant Based Protein Versus Animal Products
As mentioned above, plant-based proteins include foods like beans, legumes, seeds, nuts, soy products and vegetables. While some of these plant based protein sources don’t contain as much protein when compared to a steak or chicken breast, they offer other nutritional benefits. Plant-based proteins typically contain fewer calories, significantly less fat, and more fiber. They may offer a host of other nutritional sources like vitamins and minerals that are not found in animal products. Animal products are typically heavy in fat, particularly saturated fat, as well as cholesterol. These two components are not the optimal choice for heart and vascular health. Also of concern, animal products may carry diseases such as salmonella or e-coli, while plant based foods are typically disease free.
Consuming red meat may also be linked with the prevalence of colon cancer. An extensive study of nearly 150,000 adults aged 50-74 years old, across 21 states, were studied over the course of ten years. Study participants provided researchers with their meat consumption data. This study, along with other studies in recent years, have consistently found that high intakes of red and processed meat were associated with not only cancer mortality, but cardiovascular disease and total overall mortality. Essentially, red meat kills.
How Much Daily Protein?
There are varying recommendations for the appropriate amount of protein consumption. There have been nitrogen balance studies that have indicated that just 25 grams per day, which equals out to less than one ounce of protein, is all that is needed for good health. However, two leading entities on nutrition suggest otherwise.
1. USDA
The Centers for Disease Control and Prevention (CDC) as well as the United States Department of Agriculture (USDA) recommend varying amounts of protein based on an individual’s sex and age. For children ages 1-3 the recommended daily intake is 13 grams and for those ages 4-8 the recommended intake is 10 grams daily. Children ages 9-13, the recommended intake is 34 grams. Girls ages 14-18 should consume 46 grams daily while boys in that same age group should consume 52 grams daily. Women older than 19 years old should consume 46 grams daily and mean older than 19 should consume 56 grams of protein daily.
2. WHO
The World Health Organization (WHO) recommends 50 grams of protein daily for all individuals. It’s believed that most individuals consume at least double this recommendation, over 100 grams of protein daily!
3. The Rice Study
One very interesting study completed many years ago found that individuals who consumed only rice for a period of 59 days, received between 1.5 and 4.5 times the amounts of amino acids recommended by the WHO. Further, all of these research participants had a positive nitrogen balance.
Too Much Protein: What are the Risks?
It’s important to understand what happens to extra protein in the body. If the body consumes more protein than it requires, the protein is not stored. Rather, it is deaminated followed by oxidation of the carbon skeleton through pathways of glucose or fat metabolism, or its storage as glycogen or fat, depending upon the specific amino acid and the energy balance at the time. Essentially, the nitrogen waste generated is then excreted in the urine. Because too much protein makes the kidneys work harder, they’re functioning could deteriorate. Individuals who already have kidney problems can add further strain to the kidneys by consuming too much protein.
Also of risk is the development of osteoporosis. A high protein diet results in urinating more calcium than individuals on a normal, balanced diet. Some health professionals believe that the urinating of this calcium can lead to osteoporosis. Further, kidney stones could also develop as a result of calcium buildup in the kidneys.
The Truth About Protein
Protein is essential to the body’s functioning, but it’s not necessary to stress about whether you are getting enough. As long as an individual is not suffering from malnutrition, they are very likely consuming ample amounts of protein. In addition, plant based proteins are the optimal source of protein for a number of reasons. They are typically lower in calories and saturated fats as well as contain other minerals and nutrients that are incredibly beneficial to the body.
