Quality aspects of food crops are traits that have globally important market economic and health repercussions in the current climate of food security. Grain legumes have high potential for the nutritional quality improvement of foods, but limited data on manipulating seed quality is available as the primary focus has been hitherto on phenotypic and agronomic trait improvement. This has resulted in a lack of innovation and low attractiveness of legume food products that, with the emergence of novel food habits, have together contributed to reduced legume food consumption. This trend now needs to be challenged and circumvented. In this review we have assessed the key factors affecting the nutritional quality of legume seeds. Protein, starch, dietary fiber, natural antioxidant compounds and anti-nutritional factors have been reviewed with emphasis on how these components might influence consumer acceptance and functional properties of legume based food products. Biofortification approaches and technological processing are discussed as ways in which the nutritional value of legumes and their consumption might be enhanced. In order to increase consumption of grain legumes, we propose that efforts should concentrate on identifying nutritionally enhanced and genetically diverse germplasm, and on linking genetics with sensorial and processing quality to assist the development of breeding/selection tools for traits that determine consumer demand. This will facilitate the implementation of quality breeding objectives in legume breeding programs, with the subsequent development of high quality raw materials for attractive legume foods. Equally important, efforts should focus on developing attractive, convenient ready-to-eat and tasty legume-based food formulations, contributing to the diversification of healthier and more nutritional diets. As a result of such a targeted effort, legume cultivation and consumption could be enhanced leading to a reduction in both the global economic burden caused by malnutrition and associated chronic diseases, and the environmental impact of agriculture.