In The Fourth Fuel, science writer Travis Christofferson weaves a fascinating narrative of humanities quest to understand how our bodies produce energy, transporting us on a scientific expedition from the past to the present, across early modern Europe to modern laboratories spanning the globe.

Christofferson reminds us that we are sicker than we have ever been. Heart disease, cancer, dementia, obesity and type 2 diabetes are rapidly becoming the norm. Yet we are presented with a revelation: the realisation that we all have a potent, and easy-to-access hybrid metabolism that generates a different fuel, the fourth fuel, that supercharges our metabolism in a way that slows aging and by-passes the metabolic dysfunction that leads to the multitude of diseases that plague modern society.