Abstract This paper analyses the use of energy in the Spanish Agri-Food System (ASF) between 1960 and 2010. It distinguishes between several different forms of energy (renewable, non-renewable, final and primary), six sectors and up to a hundred activities. The use of energy in the AFS increased 10.2 fold during the period analysed, from 181 TJ to 1855 TJ, between 1960 and 2015. In the first stage, up to 1985, agriculture accounted for the majority of new consumption. However, from that date onwards, consumption in other sectors such as transport, packaging and homes grew at a faster rate. A decomposition analysis reveals that the increase in activity in the sector, in other words managed biomass, explains 46% of the increase in the use of energy, whereas the rest is explained by losses in efficiency, chiefly losses in efficiency within a sector that requires a greater amount of resources per biomass produced. The final energy consumption of the AFS over the total consumption of the economy represents 19.6%, suggesting a significant potential of agri-food policies as means of reducing the use of energy.