Food, Energy, And The Evolution Of The Human Species

Why do we eat what we eat? Why don’t we eat what we don’t eat? There are many ways to approach these questions, but from an evolutionary perspective an important answer involves the bioavailable energy we can derive from different foods given our digestive system and physiology.

In this episode of A Worldview Apart I explore the energetic roots of the evolutionary process, particularly in the context of how we, as a species, evolved over millions of years to look and behave so differently than other Great Apes. I explore the importance of energy input-output ratios in the evolutionary process, and how tools use, clothing, and fire aided our question to acquire ever more edible calories from the landscapes we inhabit all while minimizing the energy we expend to acquire those calories.

Episode Outline

  • Past consulting projects that included energy life cycle assessments of farm products
  • Food as edible calories, and the difference between a chemist’s calories and a nutritionist’s calories
  • The role of energy acquisition in the evolutionary process of natural selection
  • How the energy a species can acquire from its landscape influences its natural range
  • Energy acquisition of early humans and how tool use, clothing, and fire made us more successful (and ultimately made us the humans we are today)
  • The costs and benefits of cooking our food
  • Agriculture’s influence on our energy gathering success
  • The energy return of modern industrial food systems versus hunter-gatherer food systems
  • The risks of subsidizing food acquisition with energy from non-renewable resources


  • Stone Age Economics, by Marshall Sahlins, is a fun, albeit one-sided, book that explores some of the themes I discuss
  • Among the sharp folks who laid the energetic foundations of the ideas I talk about are Alfred Lotka, Howard and Eugene Odum, Richard Pinkerton, and Charles Hall
  • I use statistics from the US Bureau of Economic Analysis and the US Department of Agriculture to estimate the metabolic energy return of the US food system
  • I use statistics from the same USDA website linked immediately above with data presented in the report Energy Use in the US Food System to estimate modern food energy input/output ratios inclusive of industrial energy sources