Think of protein as an alcoholic beverage.
You’re standing at a bar, and you’ve got a bottle of gin, some Campari, and and a bottle of vermouth. You can only have one drink, and you’re trying to feel a nice buzz.
There're a few ways to achieve this.
One option is to pour out some straight gin and go for it.
Another option is to grab all three bottles and throw them together to make....
Either way you’ll get buzzed, it’s just a matter of personal preference.
Ok, so think of all these bottles as proteins. This gin is a complete protein. The others are incomplete proteins.
Now in this scenario we can equate "trying to get a nice buzz on" with "trying to build muscle." In order to build muscle and feel satiated and get our ideal bodies, we gotta consume protein.
But not all proteins are created equal.
Proteins are basically just chains of amino acids.
There are two types of amino acids:
Nonessential amino acids are created by the body (so you don't have to worry about those), but essential amino acids are not and must be obtained from food.
And in order to really build muscle, we wanna get all of 'em.
So, back to the bottles.
The gin is high proof and will get you drunk quick— this is the "complete protein."
The others are lower alcohol and could be consumed alone, but they serve their purpose much better when consumed together in a mixed drink. These are the "incomplete proteins."
Complete proteins contain all the essential amino acids in sufficient quantities, while incomplete proteins need to be combined together to create a complete protein.
Complete proteins are typically animal-based (meat, fish, dairy products, eggs, etc.), however there're a couple other plant-based complete proteins as well, such as quinoa, buckwheat, hemp, and chia.
Incomplete proteins (the ones that should to be combined) account for pretty much every other protein in the world-- grains, legumes, nuts, vegetables, etc.
In other words, the less animal-based proteins you consume, the more diverse you want your plant-based diet to be, to make sure you’re getting all your aminos.
This is particularly important if you’re a vegetarian or vegan.
To take it even one step further, you want to aim to combine what are known as “complementary proteins” to create a complete amino acid profile.
Good examples of this are:
brown rice and beans
yogurt and nuts
hummus and whole grain pita
tofu and tahini
peanut butter and whole wheat bread
So when it comes to protein, do as they say and "consume responsibly."