- Each half-cup serving of dry beans provides six to seven grams of protein, meets at least 10% of the Recommended Dietary Allowance (RDA) for protein, yet costs about 20 cents per serving.
- A single half-cup serving of cooked dry beans counts as one, one-ounce serving of lean meat in the USDA Food Pyramid Meat and Beans group, and as a full serving of vegetables in the Vegetables group.
- The quality and digestibility of beans can be improved by consuming them with cereal grains. Beans are a rich source in lysine, but a poor source of methionine. Cereal grains are a poor source of lysine, but high in methionine and other sulfur amino acids. When beans and grains are served together in dishes like beans and rice, or tortillas and refried beans, they provide a complimentary protein profile.
- There are only 100 to 120 kcalories in a half-cup serving of beans. However, Kcalories and other nutrients are diluted in canned beans because the moisture content is higher.
- Beans contain an average of 25 grams of carbohydrates per serving. The carbohydrates in cooked beans are mainly starch, a complex carbohydrate, and less than 1% of simple sugars, mostly Sucrose.
- Discarding the soaking and cooking water helps remove oligosaccharides and reduces flatulence. Hot soaking removes about 50% of these sugars. Extended soaking removes more, but reduces vitamins and minerals. Canned beans may contain up to 4% sucrose as a flavor enhancer.
- A half-cup serving of cooked dry beans provides about 25-30% of the Daily Value of dietary fiber. About 75% of the fiber is insoluble which may reduce the risk of colon cancer. The remaining 25% of the fiber is soluble fiber which may reduce blood cholesterol. Studies have confirmed that beans are effective hypochoesterolemic agents when added to the diet.
- Consumption of beans produces a moderate increase in blood glucose and insulin levels which may be helpful in the metabolic control of diabetes. The American Diabetes Association and the American Dietetic Association include beans in the exchange system.
- The slower release of glucose and the increased satiety from beans may also to enhance the effectiveness of weight-reducing diets.
- A half-cup serving of beans contains less than 0.5 grams of mostly polyunsaturated fat and no cholesterol. Pinto bean lipid is 84% polyunsaturated fatty acids. Most of this fatty acid is linoleic acid.
Vitamins & Folacin
- Although some B vitamins are lost in preparation, cooked dry beans retain more than 70% of these vitamins after hot soaking and cooking. Extended cooking times will result in greater B vitamin losses.
- One half-cup serving of beans provides 36% of the Recommended Daily Intake (RDI) of 400 micrograms of folacin and 11% of the RDI for thiamin.
- One half-cup serving of cooked dry beans contains large amounts of iron, phosphorous, magnesium, manganese, potassium, copper, calcium, and zinc.
- The iron and calcium content can increase slightly when hard water is used for home preparation. Canned beans sometimes contain added calcium to increase firmness.
- The bioavailability of these minerals is somewhat lower due to the presence of fiber, phenolic compounds and phytic acid, which decreases their absorption. The absorption of the nonheme form of iron in beans can be increased by consuming beans with a source of vitamin C, or with small amounts of meat.
- One half-cup serving of cooked, unsalted dry beans contains 500 mg of potassium and small amounts of sodium. The level of potassium may be useful in a hypertensive diet.
- One half-cup serving of salted beans provides nearly 20% of the Daily Value for sodium on a 2,000-calorie diet. Most commercially prepared canned and dried beans contain added sodium for flavor. Check the label to determine sodium content.