As is the case with most legumes, kidney beans are a nutritious and protein-rich food. One cup of the raw beans contains 43 grams of protein, 46 grams of fiber (almost double your RDA), and is 613 calories. They also have a high amount of antioxidants.
ORAC Source
USDA Database for the Oxygen Radical Absorbance Capacity (ORAC) of Selected Foods, Release 2 - Prepared by Nutrient Data Laboratory, Beltsville Human Nutrition Research Center (BHNRC), Agricultural Research Service (ARS), U.S. Department of Agriculture (USDA) - May 2010