The global demand for milk protein has increased significantly in recent years due to better understanding of its nutritional value, physiological and bioactive properties. A growing body of research shows that a greater intake of protein may be beneficial in sports performance, weight management, lean muscle mass retention, satiety and general wellbeing. Much of the evidence regarding many of these health benefits focuses on milk proteins, particularly whey proteins. As a result, the demand for milk protein-enriched food and beverage products has increased enormously over the last 5 years. Several milk protein products, such as milk protein concentrates, whey protein concentrates and whey protein isolates, are now available and can be added to beverages, yogurt, soups, desserts and bars. However, some functional properties of milk proteins, such as aggregation and viscosity, pose challenges to developing acceptable food formulations at high protein concentrations. For example, the addition of protein will typically cause a food product to become excessively thick and will create stability issues during processing. In addition to maintaining suitable stability and texture, protein at high concentration has a marked impact on the taste and flavor profile of the product. Although some solutions to these problems have been developed by the food industry, we need to have better understanding of the fundamental behavior of proteins at high concentrations in various food formats.Recent studies indicate that beneficial effects of protein on health are not just dependent on sufficient protein intake; the rate at which amino acids are released and absorbed, as well as the generation of bioactive peptides influence biological potency. Thus, the interactions of milk proteins in the food and in the gastro-intestinal tract can play an important role in modulating the efficiency of protein digestion and the magnitude of its biological effects. In the future, it may be possible to design structures based on milk protein preparations to optimize the delivery of amino acids, hence modulating the postprandial physiological responses.