What is a Complete/Incomplete Protein? Here’s Everything You Need to Know
We hear about protein all the time; it’s the stuff that helps powerlifters gain mass, it provides us with crucial energy, and it’s one of the main nutrients we need to survive and thrive. But is all protein created equal? Is the protein you get from a handful of almonds the same kind as what you get in chicken breast? And furthermore, what difference does it make? In order to answer these questions, we need to understand the difference between complete and incomplete proteins.
Protein 101
But first, a brief review of the almighty protein...
Protein is one of three macronutrients required by all humans, alongside carbohydrates and fats. If it seems like people are always harping on the importance of protein, consider that, other than water, proteins are the
most abundant substance in the body. And once they’re inside, they really get to work. Proteins play fundamental structural roles in the creation of cells for muscles, organs, skin, blood, and hair.
We all know that protein is essential for energy; each gram contains about 4 calories and provides a host of vitamins and minerals to help the body function to its fullest. Once broken down, proteins become amino acids, which are crucial for everything from hormone production to cellular repair.
What Are Essential Amino Acids?
There are 20 common amino acids that make up proteins, 9 of which cannot be synthesized by the human body. This means we need to get them from somewhere else—namely, food. These 9 essential amino acids are phenylalanine, valine, threonine, tryptophan, methionine, leucine, isoleucine, lysine, and histidine, and they appear in different concentrations in different types of foods. This brings us to our question of complete vs. incomplete proteins.
Complete vs. Incomplete Proteins
Bearing in mind our list of 9 essential amino acids above, it becomes easier to understand what a complete protein is. Complete proteins are those that contain a sufficient proportion of all 9 EEAs. For the most part, complete proteins are found in the form of animal-derived products such as beef, chicken, fish, eggs, cheese, and yogurt. However, some plant-based sources, such as hemp seed, quinoa, and soybean, are considered complete proteins as well.
On the other hand, incomplete proteins are those that lack a sufficient amount of one or more essential amino acids. Incomplete proteins largely come in the form of plant-derived foods such as grains, nuts, seeds, beans, lentils, and peas.
What If I Don’t Eat Meat or Dairy?
So, does being vegetarian or vegan mean it’s impossible to get a complete range of essential amino acids from your diet, or do you have to take some crazy supplement to receive adequate amounts? Luckily, this is not the case. Although there is no way to magically make incomplete protein sources complete, you can combine them to do just that!
For example, on their own, black beans contain good amounts of many essential aminos, particularly lysine, but lack adequate methionine. Conversely, grains like rice lack lysine, but
contain sufficient methionine. Combine them and what do you get? A complete protein, that’s what!
How to Balance Health and Protein Intake
As you can see, there are ways to use plant-based food sources to achieve your daily recommended intake of complete proteins. If you do eat meat, but are looking to cut back for health or weight reasons, consider combining small portions of meat with other complete or incomplete plant-based proteins. Quinoa is quite unique with its complete amino acid profile, and it makes a great base for all types of versatile meals. Stir fries, patties, you name it—there’s a way to stay healthy while still getting adequate protein.
A Note on Complete Proteins and Nutrition
It’s crucial to observe that complete proteins aren’t inherently nutritious, especially if consumed in excess amounts. For example, red meat is a complete protein, but eat that every day and you won’t be happy with where it gets you. This doesn’t mean you should never eat it, but don’t think that its amino acid profile automatically makes it a health food. And furthermore, know that processed meat and dairy products often detract from the overall nutritional value. As such, consider the amino acid content of your proteins as one factor in your diet, but not the only.
How Much Total Protein Do I Need per Day
Daily protein requirements vary greatly based on age, weight, physical activity level, and more, but the World Health Organization recommends between 46–56 grams of total protein per day for a 137 lb sedentary adult. This recommended dietary allowance (RDA) breaks down to roughly 0.8 grams of protein per kilogram of body weight (0.36 g/lb).
Again, this figure can increase significantly depending on activity level. This is backed up by a
2012 review published in the Journal of the International Society of Sports Nutrition that sought to determine the effects of increased protein intake on muscle gain in resistance training. The review ultimately looked at 17 studies that met their criteria, supporting a longstanding “lay” conclusion that at least 1 gram of protein per kilogram of body weight is beneficial to increased strength and body composition.
A
2011 study published in the Journal of Sports Science takes this one step further, suggesting a protein intake of between 1.3–1.8 g of protein/kg of body weight over 3–4 meals per day for athletes.
The Possibilities Are Endless!
As we’ve demonstrated above, there’s no need to fear incomplete proteins, nor do you need to excessively favor the complete. Through informed meal prep, and by using versatile plant-based ingredients as a foundation, there are an untold number of protein-rich meals that will provide every cell in your body with the energy it needs to keep you healthy, active, and vital for as long as possible!