The Protein in Rice and Beans

Rice and beans may seem like a simplistic meal without enough protein or nutrition. It turns out, however, that rice and bean dishes have complete proteins, are packed with carbohydrates, protein and nutrients you may need for a vegan diet or fitness plan, and are totally delicious.

When you're doing research on the best protein-packed diets for either muscle gain or weight loss, you may discover that there are different types of protein. You may come across the terms "complete" or "incomplete" proteins.

According to the Food & Drug Administration (FDA), complete proteins contain full doses of all nine essential amino acids. Most complete proteins come from animal-based foods, like meat, poultry, seafood, eggs and dairy products.

Some complete protein examples include chicken, salmon and tuna. Soy is the one plant-based protein that is considered a complete protein, but most plant-based proteins don't contain all nine essential amino acids.

The nine essential amino acids are histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine. They are all are required for the body to perform a whole variety of processes, including helping to build muscle, to grow skin and to fuel organs.

Most plant-based proteins don't contain all nine essential amino acids. Beans, for example, are missing an amino acid known as methionine, according to the American Society for Nutrition.

Other plant-based protein foods, like pea protein or nuts, are often missing an essential amino acid known as lysine. Beans, however, contain lysine.

The best solution to this problem is to mix and match your plant-based sources, often with whole grains, so that you're getting the full spectrum of amino acids your body needs to function. There are ways to eat a vegetarian or vegan diet and still receive all nine essential amino acids, by combining beans with grains (so you get both methionine and lysine, as well as the other amino acids), or through other variations.

This is where rice and beans come in. Rice and beans are, separately, both incomplete proteins; but when they're eaten together, they're considered complementary proteins, according to the FDA.

When consumed together, each provides the amino acids that the other lacks. Rice doesn't have enough lysine, but beans do. Meanwhile, rice has high levels of the amino acid methionine, which beans lack.

Read more: Starchy Vegetables and Foods to Fuel Your Body

Together, rice and bean dishes become complete protein examples. The same can be said for peanut butter and whole wheat bread, which explains why both of these dishes can be incredibly filling without meat.

Beans are known for being a strong source of plant-based protein, as well as for containing a lot of fiber. But they're also healthy for you in a lot of other ways, and it turns out they're the nutrition-packed star of a rice and beans dish.

Beans are a part of the legume family, and are pod seeds from a flowering plant family known as Fabaceae. Lentils, peas, chickpeas and soybeans all fall into the legume category. Legumes are touted for their nutritional benefits; they're high in fiber, in folate and in manganese. They also have very low levels of fat and sodium.

One cup of black beans, for example, contains about 15 grams of protein and less than a gram each of fat and sugar. Beans are a common source of protein for vegans and vegetarians, where they're used in dishes like veggie burgers.

Beans also contain phytochemical properties that work as antioxidants, according to an August 2015 study published in Nutrients. In the study, black beans showed an ability to reduce insulin concentrations in the body, which could help manage metabolic health. They may also protect against the risk of cardiovascular disease and diabetes.

The American Heart Association recommends beans as good dietary choices to lower cholesterol and aid in weight loss. That's why popular heart-healthy diets, like DASH and the Mediterranean diet, emphasize legumes and beans.

Legumes and beans have also been linked to lower risks of heart disease, hypertension, stroke and Type 2 diabetes, according to an October 2015 study published in Clinical Diabetes. That same study notes that beans are filled with a healthy array of nutrients, including fiber, protein, healthy carbohydrates, B vitamins, iron, copper, magnesium, zinc and manganese.

You can't have a delicious rice and beans dish without the second-most-important part — the rice. While the rice aspect of this combination dish is considered the less healthy of the pair, rice — when chosen properly — can provide you with needed health benefits as well.

Rice happens to be a staple food in many countries around the world, including Spain, China, and India. There are also thousands of different types of rice, categorized by their length and width, according to the Harvard T. H. Chan School of Public Health.

One of the most popular types of rice, white rice, may not be the healthiest choice — it's mostly filled with carbohydrates, and is lower in protein than brown rice. Fortunately, there are plenty of other, healthy rice options you can use to create the best ratio of rice to beans.

One cup of whole-grain rice, often referred to as brown rice, can contain up to 5 grams of protein, and also contains significant bio-available magnesium, zinc and iron. Because brown rice hasn't been refined or stripped of its bran, germ and endosperm, it contains more of the fiber and nutrients in these layers than white rice does.

Read more: Beans and Digestive Problems

There are also black, purple and red rice, which often contain healthy phytochemicals called anthocyanins, according to the Harvard T. H. Chan School of Public Health. These are antioxidants that are also found in berries. Black, purple and red rice retain the bran and germ layers, like brown rice, making them another more-nutritious choice than white rice.

The fun part of creating rice and bean dishes is experimenting with new additions, tastes and spices. Rice and beans may seem boring, but you can start out by choosing new types of beans and rice to mix things up.

While beans may seem simple and bland, there are actually thousands of different types of beans. There are fava beans, runner beans, lima beans and common beans — which include kidney beans, black beans and green beans, among others. Kidney beans have 15 grams of protein per cup, and black beans contain about the same amount.

Next, choose the best ratio of rice to beans to maximize the health benefits of the dish. While the ratio is typically half and half, the best ratio of rice and beans may be higher in beans and lower in rice than that. If you want to pack in more protein and fiber, as well as the higher nutrient quality of beans, you may want to create a dish consisting of two-thirds beans and one-third rice.

For inspiration, you can rely on the array of cultural cuisines that use rice and beans, such as Caribbean and Latin American. For example, you can make a staple Nicaraguan version of rice and beans with red kidney beans, sautéed garlic, chopped onions, green pepper and fresh herbs.

For an easy red beans and rice recipe, try one from the United States Department of Agriculture. Then toss in any spices you'd like. Those can include paprika, chili powder, cumin and coriander. Once you've mastered the skills of making rice and bean dishes, you'll find them to be a tasty addition to a healthy diet.