Energy efficiency and nutrition in societies based on human labor

Abstract

Improving the conditions of poor traditional societies is a standard goal of development policies. The definition of ‘improvement’ requires a previous definition of values, that is to say, ‘better’ or ‘worse’ can change according to the parameters used to optimize the system. Different scientific disciplines generally focus on different levels of analysis: the individual, the socio‐economic, or the environmental level. Consequently, optimization parameters derived from single disciplines are not holistic in assessing development. System energy analysis can provide a way to describe the interaction among individuals, human societies and natural processes, that bridges the different levels of analysis. This paper investigates the relationship between nutrition and energy efficiency in farming systems based on human labor. By describing the energetic budget of a society, trade‐offs can be assessed between a better diet at individual level, and the consequent decrease in the conversion ratio of energy input into applied power at societal level (more elderly, larger body size, dramatic increase of energetic cost for nutritional calories). The relationship between energy efficiency and nutrition in the process of societal development is also addressed.