situations. These models generally possess the following components according to Stephens et al. 2007;
*Currency: an objective function, what we want to maximize, in this case energy over time as a currency of fitness
*Decision: set of choices under the organism's control, or the decisions that the organism exhibits
*Constraints: "an organism's choices are constrained by genetics, physiology, neurology, morphology and the laws of chemistry and physics"Some of these versions include:

The optimal diet model,