These diet examples are from a series of diets with the following features: casein-based, isocaloric (3.8 kcal/g) and matched for fat (5.5%), calcium (0.7%), and phosphorus (0.54%). There are other diets available from this series of diets, as well as other unique protein adjusted diets.

Casein is the most widely used refined protein source, but it is also possible to use other refined protein sources, such as "vitamin-free" test casein (alcohol extracted), lactalbumin, isolated soy protein, and egg white solids. These particular protein sources are usually used to achieve a specific research objective, rather than for routine use. For instance, vitamin-free test casein is most appropriately used in vitamin deficient diets, and egg white solids is most suitable for zinc or biotin deficient diets.

Adjusted protein diets usually range from "protein-free" (trace) to 60% protein, depending on the research.