Legumes and grains are a good source of protein, particularly in a vegetarian diet. Barley is a grain that is also a good source of fiber, and lentils belong to the legume family, along with beans. Whether you are following a vegetarian diet and need complete sources of protein, or are replacing meat in a few meals a week, dishes that include barley and lentils are a tasty choice.
Protein is important for building muscle, but beyond that it plays a role in maintaining all of the organs and tissues in the human body. Amino acids make up protein, but many are not made by the body and are only found in food sources. These are called essential amino acids, and according to the Centers for Disease Control and Prevention, sources of protein are classified by the amount of amino acids they contain. Meat provides all the essential amino acids needed by the body and is considered a source of complete protein. Plant sources of protein, such as barley and lentils, do not contain all of the essential amino acids, but when they are combined they do add up to a complete protein source.
Barley and lentils are sources of incomplete protein because by themselves they do not provide all of the essential amino acids you need. When you combine them they are called complementary proteins because together they provide all of the essential amino acids. Eating barley and lentils in the same dish or during the same meal is an easy way to get complete protein, but you do not have to eat them together. If you eat incomplete proteins at separate times during the day your body will still combine them into a complete protein source, so you can have barley for lunch and lentils for dinner and get all the protein you need.
A cup of cooked barley contains 3.5 grams of protein, 193 calories and less than 1 gram of fat. A 1/4-cup serving of cooked lentils provides 8 grams of protein, 130 calories and half of a gram of fat. If you eat 1/2 cup of barley with 1/2 cup of lentils you will get nearly 18 grams of complete protein. Barley and lentils are also excellent sources of fiber, which MayoClinic.com points out is important for healthy bowels and may help lower cholesterol levels, maintain blood sugar levels and help you lose weight.
While you can eat barley and lentils separately at different meals, combining them boosts nutrients and flavor in a dish. Soups and stews with barley and lentils are hearty. Use plenty of vegetables, such as carrots, onions and sweet potatoes, when creating your dishes to increase the nutrient levels even more. Combine cooked barley and lentils to make vegetarian burgers. Cook and cool barley and lentils and combine with an olive oil vinaigrette and raw vegetables for a luncheon salad.