Protein 101: A Beginner’s Guide to Dietary Protein

Protein, protein, protein. You’ve probably heard this term quite a few times by now or seen it increasingly promoted in food products at your grocery store. This guide will review the basics of protein, its functions, health benefits and more.

So, what is protein and why is it so important?

The quick answer: Protein is an essential macronutrient. It is the building block of nearly all tissues and organs in your body.

Protein & Amino Acids: The Basics

All protein is made up of 20 amino acids. Nine of the twenty amino acids are considered essential because the body can’t make them, and they have to be consumed through your diet–from protein sources. The remaining 11 are non-essential because the body can make them. Some of the non-essential AAs can become conditionally essential, because under certain circumstances like stress or illness the body needs more than it can produce.

Where can you get protein from? 

  • Animal sources (seafood, meat, poultry, eggs, dairy products)
  • Plant sources (beans/peas, whole grains, nuts, seeds and soy or soy products)
  • Protein-powder supplements (either plant- or animal-based)

Though most animal sources are rich in protein (unlike most plant-based sources), animal sources can also contain saturated fat and cholesterol (which plant-based sources don’t contain). Whole food plant-based proteins like beans and whole grains don’t contain as much protein (so you have to eat more volume), but they contain other incredibly beneficial nutrients like fiber, antioxidants, anti-inflammatory compounds, etc. This is why it’s best for most people to get protein from both sources. The benefit of protein powders like Growing Naturals rice and pea proteins, is that they are rich in plant-based protein but low in volume.

What is a complete vs incomplete protein? 

A complete protein is a protein that provides all nine essential amino acids in the proportions needed to single-handedly build new tissue aka protein synthesis. An incomplete protein is low in one or more essential amino acid and thus can not single-handedly support tissue building. However, incomplete proteins can be “combined” to be made complete. That is, they should be consumed with other protein sources in order to provide the body with needed amounts of all essential amino acids. They do not have to be consumed in the same meal. They can be consumed throughout a 24 hour period.

  • (Individual) Complete proteins: Most animal-based proteins; seafood, poultry, meat, dairy products, and soy or soy products
  • (Individual) Incomplete proteins: Most plant-based proteins; grains, legumes, nuts and seeds

Note: Contrary to belief, hemp and quinoa are not complete proteins on their own. As shown in this study, hemp is low in lysine. Quinoa is low in tyrosine + phenylalanine as shown in this study.

Either or both complete and incomplete proteins can be consumed to help meet your daily protein requirements.  You don’t need to consume complete animal-based proteins in order to meet your daily protein need, as is evident with healthy vegan diets. It is entirely possible to meet your protein goal with only plant-based proteins. You just need to make sure you are 1) eating a range of complementary proteins and 2) eating enough total protein each day.

Grains and legumes are the most common complementary proteins because the combination of their amino acids, yields a complete protein. In other words, the amino acids in legumes help to complete the amino acids in grains and vice versa. Specifically, legumes are typically high in lysine and low in methionine/cystine, whereas grains are high in methionine/cystine and low in lysine.

Here are some examples of ways to get complete plant-based protein:

  • A bowl of oatmeal for breakfast and chickpeas on a salad for lunch
  • A meal with rice + beans combined
  • A meal including pita bread + hummus
  • Seasoned tofu on a quinoa salad
  • Whole wheat toast as a breakfast side and refried beans on a taco for supper

What is Protein Good for? 

Aside from being the building block of all cells, protein has other major functions in the body including:
  • Building valuable enzymes (compounds) that regulate daily bodily functions (like digestion, providing energy, regulating your sleep/wake cycle, regulating blood sugar)
  • Transporting nutrients, oxygen, and waste throughout the body
  • Creating the structure and flexing ability of muscles
  • Providing collagen to connective tissues of the body and to the tissues of the skin, hair, and nails

What are the Health Benefits of Protein?

Protein appears to play an important role in:
  • Supporting the immune system
  • Weight management
  • Controlling blood sugar
  • Maintaining muscle mass
  • Building muscle mass and muscle recovery
  • Proper growth and development during infancy, childhood and pregnancy

Immune Health

Protein is one of several nutrients which help to support the immune system.  Amino acids from protein help to build antibodies which make up the immune system. Without enough protein, the body is unable to make enough antibodies which are needed to defend against harmful invaders like bacteria, viruses, etc.

Weight Management 

High protein diets have been associated with weight management and weight loss by increasing satiety in a meal and to a lesser degree, from the thermic effect of protein.

  • Protein keeps you satiated. Consuming protein as part of a meal will help to keep you satiated (full for longer). And longer than fat and carbs alone would.  For example, a fruit smoothie with added protein powder will keep you fuller for longer than a plain fruit smoothie. Thus, with protein-rich meals you tend to eat less frequently and consume less calories throughout the day, which can help to manage your weight.  Additionally, studies have shown that eating a high-protein snack before a meal will help you to consume less calories in the following meal.
  • Protein metabolism burns calories. The amount of energy that your body “burns” from digesting protein is called the thermic effect of protein. This thermic effect is greater from protein than it is from digesting fat or carbs. Thus, when eating a high-protein diet you tend to burn more calories than a regular diet.

Controlling Blood Sugar

When consumed as part of a meal with carbohydrates (sugars), protein will help to offset any spikes in blood sugar which would normally be caused by carbs/sugar alone.  By keeping blood sugar regulated, you avoid sudden peaks and drops in energy, which can lead to fatigue or tiredness, which can be confused for hunger and often leads to overeating.

For example, this vanilla protein latte with 26g of protein is sure to keep your blood sugar better regulated than a regular high sugar, no-protein latte.  It will also keep you full!

Maintaining Muscle Mass 

  • Protein supports muscle mass during restrictive, weight loss diets.
    • Eating a high protein diet can help to preserve muscle mass (and thus metabolism) during low calorie (weight loss) dieting.  Muscle loss is common for many during weight loss diets (since many people just focus on eating less food). What happens is that when the body is suddenly restricted on calories/energy, it may start to break down some muscle mass and convert it into energy.  This can in turn lead to a slowed metabolism. High protein diets may help to offset this effect.
  • Protein supports muscle mass as you age.
    • Adequate protein consumption is important after the age of 30 to help preserve muscle mass.  You can lose 3%-8% of muscle mass each decade after the age of 30.  This condition also known as “sarcopenia,” occurs primarily due to lack of physical activity, strength training or insufficient intake of dietary protein.  If muscle loss continues, it can lead to loss of strength, stability, energy and slowed metabolism, which often results in weight gain.

Building Muscle Mass and Muscle Recovery

Protein is a key nutrient for any exercise enthusiast, but especially if you are looking to gain muscle mass or improve your body composition.  The greater your physical activity level, the higher your protein requirements will be because amino acids are your muscles’ building blocks–how they recover and get stronger. Learn more about protein for muscle mass and recovery here.

Supplementing with rice protein in particular has been shown in both collegiate athletes and elite athletes to build and maintain muscle mass to the same degree as animal-based whey protein.

Healthy Development During Growth Periods

As the building blocks of all cells, dietary protein is especially important to consume during growth periods like childhood and pregnancy. Because your body is physically building so many new things, your body requires more amino acid “building blocks” during these times. Not getting enough protein during these times can lead to stunted growth or other health issues, trickling down from lack of proper development.

How much protein do I need? 

Not many people lack enough protein in their diet, especially not if you consume meat/poultry regularly. However, if you have many dietary restrictions, follow a plant-based lifestyle, or are vegan, it may become more challenging to consume enough protein. This also goes for people with very high protein needs, like athletes or sports enthusiasts following a plant-based diet. Check out our protein calculator to find out how much protein YOU specifically need on a daily basis.

Take Inventory

Once you find out how much protein you need each day, you can use a food tracking app such as MyPlate or MyFitnessPal to help you figure out if you are meeting your daily requirement.  You may be surprised how many days you fall short of protein needed to maintain your body’s health.

How do I use protein powders? 

Protein powders like Growing Naturals’ rice and pea protein are a convenient way to help fill nutritional gaps with concentrated plant-based protein.  You can use them to supplement when you aren’t getting enough protein from whole food or use them as alternative protein sources. Rice and pea protein in particular are low in fat, calories and naturally cholesterol-free compared to most animal-based proteins. And did you know there’s tons of ways to use them other than just smoothies and shakes?

Regardless of what type of protein you decide is best for your health and lifestyle, what’s most important is to make sure you’re getting enough protein each day to support and maybe even enhance your health.


By: Scarlett Full, in-house Registered Dietitian

Older Post Newer Post