Protein-Energy Interactions (IDECG, 1991, 437 p.): The metabolic basis of amino acid requirements: 3. The Millward & Rivers requirement model: Qualitative aspects

Protein-Energy Interactions (IDECG, 1991, 437 p.)

The metabolic basis of amino acid requirements

		(introduction...)
		Abstract
		1. Introduction: The nature of the problem
		2. Nutrient requirement models
		3. The Millward & Rivers requirement model: Qualitative aspects
		4. The variable extrinsic component of the maintenance requirement
		5. The anabolic drive
		6. Hormonal components of the anabolic drive
		7. Protein requirements: Formal statement
		8. The issue of protein quality
		9. Stable isotope studies
		10. Practical experience of biological values of dietary protein
		11. Urea salvage
		12. Indispensable amino acid requirements for the anabolic drive
		13. Conclusions
		References

3. The Millward & Rivers requirement model: Qualitative aspects

One way of representing the model qualitatively is shown in Figure 3. In its simplest form, it includes needs for new tissue and maintenance. We view maintenance as a variable component, comprising both fixed functional demands and variable regulatory extrinsic components. It is defined operationally as the dietary intake needed to balance all losses, including those which occur on feeding protein.

There are three components which are functional demands or intrinsic. The first one is the fixed component relating to the net requirement, i.e., the need to deposit new protein. Conceptually this is straightforward. The other two are part of the maintenance needs. These are the intrinsic requirements for obligatory amino acid consumption in non-protein pathways, conceptually straightforward even if poorly understood, and the anabolic drive.