Abstract
Evolved constraints to human energy transformation force the body-brain system to operate an economy of energy. To survive and thrive, an organism's finite internal energy resources must be dynamically reallocated, forcing trade-offs from organelle to organism. Building on an energy trade-off framework integrating life history theory and cellular biology, we propose that energy trade-offs occur between three main classes of processes relevant to health: (i) vital, (ii) stress, and (iii) growth, maintenance, and repair (GMR). Competing demands for these processes exist within a hierarchy of energy needs where more 'urgent' vital- and stress-related functions are prioritized by suppressing longevity-promoting growth, maintenance, and repair processes. The energy constraint model of human health provides an energy-based framework to address health/disease dynamics across the lifespan.