The body and mind are fuelled by energy. But where does the energy come from? The sun beams energy through space as photons that are captured by plants, which store that energy in the improbable separation of carbon and oxygen. By reuniting carbon and oxygen in their mitochondria, breathing animals power their warm bodies, thoughts, feelings, minds and consciousness. Thus, the life-giving flow of energy proceeds from light, through chemistry, into life. Mapping the mechanisms of energy transformation among mind-imbued organisms is the challenge for the field of mitochondrial psychobiology. Emerging evidence positions energy as the substrate of the mind–body connection, linking the molecular processes in the organism and the subjective experiences in our mind. Building a bioenergetic psychobiology framework can stimulate the health sciences in three main ways: it provides an empirical foundation to examine the interconnectedness of people and their environment, highlights health as a dynamic process, and may eventually illuminate new approaches and strategies to optimize the energetic mind–body crosstalk that is the basis of human health.