This chapter discusses the simplest non-degenerated deb model that is implied by deb theory, the standard or canonical deb model, to show the concepts of the previous chapter in action. The next chapter introduces more concepts on chemical transformations to deal with more complex situations. The standard deb model assumes isomorphy and has a single reserve and a single structure, which is appropriate for many aspects of the metabolic performance of animals; other organisms typically require more reserves, and some (e.g. plants) also more structures. So in this chapter, we keep an animal in mind as a reference, which helps to simplify the phrasing. In this chapter substrate (food) has a constant composition that matches the needs of the individual. Food density in the environment might vary in the standard deb model, but the discussion of what happens during prolonged starvation is delayed to Chapter 4. The discussion of mass aspects is also delayed and we here only use time t, length L and energy E. Length L is the volumetric length, L = V⅓, where V is the structural volume. We use energy only conceptually, and typically in scaled form, and also delay the discussion of its quantification. The discussion of energy aspects does not imply that the individual should be energy-limited.

The logic of the energy flows will be discussed in this chapter and we start with a brief overview in this introductory section.