
Here at the home kitchen of Cook-N-Easy we eat lots of grain bowls. They’re easy to fix, tasty, and they’re good for us.
Non-vegetarians frequently ask, “Do you get enough protein?” As vegetarians, we need to get our protein from plant sources. Yes, we eat fish and shellfish sometimes, but most of the time we eat a plant-based diet. However, most plant proteins are not complete by themselves. You have to combine plant proteins to get complete proteins. What’s up with that?
Here’s a little technical stuff. It won’t take long so stay with me.
Proteins and their Amino Acid Building Blocks
Every day your body is busy making new cells. If you’re young, you’re still growing and that means your body is making new cells for growth. If you’re fully grown, your body is constantly replacing cells. All that new growth and replacement takes some chemicals and you get those chemicals from the food that you eat. You need lots of different kinds of chemicals, but we’re only going to talk about proteins. New cells, especially muscle cells, require proteins (and other things). You’ve probably heard of digestive enzymes that break down the food you eat. Well, almost all enzymes are proteins. Your body tears down the stuff you eat and reassembles it into things it needs, and it uses enzymes to do that.
Proteins are big molecules composed of amino acids. Your body combines 20 types of amino acids to make the proteins it needs, but only 10 of those 20 amino acids must come from the food you eat. You can make the other 10 inside your cells. The 10 that you must get from the food you eat are called essential amino acids. As you go about your day eating this and that, you need to consume those 10 essential amino acids to allow for proper protein synthesis.
Because you might be wondering, here are the 10 essential amino acids:
- Arginine
- Histidine
- Isoleucine
- Leucine
- Lysine
- Methionine
- Phenylalanine
- Threonine
- Tryptophan
- Valine
Note: Some sources list only nine essential amino acids, omitting arginine from the list of essential amino acids.
Combining Amino Acids
So, let’s say you eat only brown rice one day and you get some of those 10 essential amino acids, but you don’t get all of them. That’s not a good plan obviously. But let’s say you eat some brown rice and some pinto beans. Now you’re getting all ten of those essential amino acids. That’s a good plan. Try our pinto bean brown rice grain bowl to see what a good idea that could be. Keep reading to see how to combine amino acids to get complete proteins.
“The major benefit of combining beans and grains comes from their amino acid contents. Both beans and grains are examples of incomplete protein — they contain some, but not all, of the essential amino acids. They also represent complementary proteins, which means that when you consume beans and grains together, their complementary amino acid contents provide your body with all the essential amino acids. For example, many grains are deficient in the essential amino acid lysine, a nutrient found in beans. Conversely, many beans contain only small amounts of methionine, an amino acid found in larger supply in grains.” Click here to read the full article.
The nice thing about these complementary proteins is that you don’t have to eat them at the same time. For example, you could eat a corn tortilla as part of your lunch and have some beans later in the day. Your body is smart enough to pull that all together and keep going.
How Combining Amino Acids Works – an Explanation
Let’s use pop beads to demonstrate this concept. The image below shows all ten essential amino acids. This is the goal – to consume amounts of each type of amino acid so that you get all ten. Assume the lime-green one on the end is lysine, found in beans, and the purple one on the other end is methionine, found in grains.

If we eat only grains, we won’t get any lysine. Conversely, if we eat beans but no grains, we don’t get enough methionine. I’m sure you have it by now: eating grains plus beans supplies all ten essential amino acids. See the figure below.

Note: Obviously 9 + 9 does not equal 10, but in this case, we’re only adding the missing amino acids. Both beans and grains have the same 8 essential amino acids and each one has an additional amino acid. Combined, you get all ten essential amino acids – the 8 found in each food type plus the lysine in beans and the methionine in grains or, 8+2=10.
Ways to Combine Grains and Beans

We, modern humans, like to think we’ve come up with all the best ideas, but people have been combining foods to get complete proteins for as long as we’ve been around. We don’t know who first put beans on a corn tortilla, but they sure had the right idea.
Here are some common combinations that you’ve probably eaten: beans and rice, pita bread and hummus, corn chips and bean dip, bean soup and crackers, peanut butter on bread, and the list goes on.
Soups that contain beans – like black bean soup and our vegetable bean soup – can be combined with whole grain bread or crackers resulting in complete proteins. On the other hand, minestrone with pasta and beans provides complete proteins.
The picture below shows some common grains and beans. Grains are things like barley, rice, freeka (made from wheat), and corn. Beans are things like pinto beans, black beans, adzuki beans, and so on. Lentils and green peas are legumes as are pinto beans and other beans. Quinoa, not really a grain, is sometimes lumped in with grains.

What about nuts and seeds? Because they contain tryptophan, methionine, and cystine, nuts combine with other foods such as legumes to make complete proteins too. Adding nuts or seeds to your grain bowls not only gives you more flavor, it can provide more protein and some healthy oils.

Plants that Provide Complete Proteins
Not all plant proteins are incomplete though. Here are some plants that provide all 10 essential amino acids: soybeans, quinoa, amaranth, chia seeds, and hemp seeds. Because quinoa provides all ten essential amino acids, you don’t really have to combine it with beans, but it tastes pretty good combined with things, so we do it anyway as we did in our black bean quinoa bowl.
Soybeans are also known as edamame so if you prepare our colorful edamame slaw you’ll be getting complete proteins in that. And you thought it was just a side dish.

Benefits of Grain Bowls
But, as important as protein is, our bodies need other nutrients too. We need some sugars, some vitamins, and other things. When you add fresh greens and other vegetables to a grain bowl, you can get everything you need in one bowl. I think that’s amazing. Here at Cook-N-Easy we don’t subsist solely on grain bowls, but because they’re such power meals, we do eat them at least once a week.
Here are some grain bowls and other grain and bean combinations to try:
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