The Basics of Protein

Dietary protein is an essential macronutrient, which is required by all healthy adults on a daily basis. It’s imperative that all healthy adults consume adequate amounts of protein whether they are active or not. To begin, we look at protein from two different perspectives – one from a nutritional standpoint and secondly from protein in the body. Dietary proteins are essential as they help to provide building blocks of proteins within the body. After a protein is ingested, it has the potential to perform thousands of different functions within the body from structure, function and regulation processes. These proteins in the body support vital functions and they function far beyond just muscle. There are many specialized proteins such as collagen, keratin, actin, myosin and more. As a matter of fact, there are potentially over a million different types of protein found in the body with many more yet to be discovered. Let’s take a closer look at protein from a dietary stance.

The Building Blocks of the Body

Different dietary proteins are comprised of different combinations of amino acids. These amino acid profiles can impact how it’s used in the body. It all begins with the foundation of proteins, known as amino acids. Proteins are complex molecules made from twenty-plus basic building blocks, called amino acids. Some amino acids can be made in the body, while others must be obtained through the diet. The amino acids can be categorized as essential or non-essential. Essential Amino Acids (EAAs) must be consumed through our diet, because the body cannot make it on its own. There are nine EAAs, which include the following amino acids: Histidine, Isoleucine, Leucine, Lysine, Methionine, Phenylalanine, Threonine, Tryptophan, and Valine. The remaining amino acids are called non-essential amino acids, because they can be produced in the body. In all, the combination and sequence in which the amino acids arranged determine how the protein will function in the body. Therefore, it’s important to consume adequate amounts of a variety of different protein sources to help provide the body with the tools it needs to create the building blocks of the body.

Protein Quality

When it comes to protein quality, not all protein sources are created equal. Different protein sources have different benefits, calories, and nutritional value and amino acid profiles. The quality of the protein source is determined by the amino acids content and its digestibility. Proteins can be categorized as complete or incomplete. A complete protein means that it contains all of the EAAs in sufficient quantities. Most animal-based sources are considered complete, some examples include foods such as chicken, turkey, beef, fish, pork, dairy, and eggs. There are also a few select complete plant-based proteins, which include soy, quinoa and pistachios. On the other hand, an incomplete protein means it is low or lacking in one or more EAAs. Most plant-based sources are considered incomplete. Incomplete protein include foods like beans, peas, lentils, nuts, and seeds. Interestingly, if you don’t consume dairy or animal-based proteins you can combine incomplete proteins to create a complete protein. It’s encouraged to consume a variety of dietary sources throughout the day to help meet dietary needs. Variety and balance are key.

Dietary Sources

The Chinese Dietary Guidelines under the Chinese Nutrition Society recommend to “eat moderate amounts of fish, poultry, eggs, and lean meat.” It’s important that all healthy adults consume a variety of proteins. This is because both animal and plant-based proteins have benefit, but supply varying amounts and ratios of amino acids. If you consume a variety of proteins, then you can increase the spectrum of amino acids in the diet. When trying to get enough protein in your diet, it’s important to choose a variety of proteins. By varying the types of protein sources you take in each day, you will conversely vary the amount of amino acids consumed. Many times people get stuck eating the same two or three foods day in and day out. While we all have our favorites, changing up your routine, including the foods you eat, may be a welcomed change. Also, if the majority of your protein is coming from plant-based sources, then try to incorporate a variety of plant proteins to help ensure you’re getting all of the amino acids you need. The table below provides examples of protein-containing dietary sources.

Amount of Protein Per Day

Dietary protein is needed by all healthy adults, regardless of activity. The amount you need each day really depends on you. Protein needs may change based upon factors such as age, body composition and level of activity. Generally, the the more active you are the more protein may be needed. For example, recreational athletes may require more protein than those who are sedentary. Endurance athletes may require more protein than recreational athletes. Strength athletes may require more protein than endurance athletes. Protein needs are relative to you and your goals. Generally, healthy adults should aim to get 0.8 – 1.2 g of protein per kilogram of bodyweight each day, while those who are participating is sports and athletic endeavors may want to increase their protein intake to upwards of 1.2 – 2.2 grams of protein per kilogram of bodyweight per day. Note that this total amount would be divided out among the various meals and snacks you consume each day. It’s important to keep a balance of all the macronutrients including carbohydrates and dietary fat. It is possible to overdo a good thing. Be mindful of balance, variety and moderation. Below are some examples of ways to add protein to your diet.

• 3 oz. / 85 gram Chicken Breast
• 3.3 oz. / 94 gram Steak
• 3 oz. / 85 gram Pork Chop
• 4.4 oz. / 125 gram Salmon
• 8 Medium Shrimp
• 24 Medium Oysters
• 4.6 oz. /130 gram Lobster
• 2.5 Cups / 600grams Plain Yogurt
• 3 Cups / 700 mL Cow’s Milk
• 4 Cups / 945 mL Soy Milk
• 4 Large Whole Eggs
• 5 oz. / 140 grams Tempeh
• 1.25 Cups / 345 grams Tofu
• ~100 g of Peanuts
• ~100 g of Almonds

Wrap Up

Your body needs protein every day and how you consume it is entirely up to you. Protein should be consumed throughout the day as part of a healthy diet. Aim to include protein-containing foods with meals and snacks. If active, then include protein around activity to help support muscle. Ultimately, if your protein needs aren’t being met, then your body’s overall needs aren’t being met. Remember, protein can be found in a wide variety of food sources both plant and animal-based. Vary your protein sources to help increase nutritional value. Find what best fits your body and goals.