Whey is a disposal problem to the dairy industry and a worsening management issue. Whey contains protein constituents with useful and, in many cases, unique properties of relevance to their use as food ingredients. To date however, whey proteins have only seen limited food use, usually as ingredients imparting structure and texture. Whey proteins have great potential in the areas of nutrition and physiological functionality, and these features should encourage their greater use as food ingredients. First, whey protein is easily digested and is effective in meeting the body's amino acid and energy requirements, and is arguably the most economical quality dietary protein source available. Second, development of industrial technologies for isolation of whey protein fractions now facilitates the preparation of infant formulas with protein compositions more reflective of human milk. Finally, using an animal model of colon cancer, evidence indicates that dietary whey protein significantly retards the development of colon cancer, and thus has potential as a functional food ingredient. These features strengthen the argument for greater use of whey proteins in any modern whey management strategy.