This indicator is calculated by FAOSTAT/ESS and is part of the FAO Suite of Food Security Indicators -- Dimension: availability (http://www.fao.org/economic/ess/ess-fs/ess-fadata/en/#.WTlX9BPytPU). The indicator expresses the Dietary Energy Supply (DES) as a percentage of the Average Dietary Energy Requirement (ADER). Each country's or region's average supply of calories for food consumption is normalized by the average dietary energy requirement estimated for its population to provide an index of adequacy of the food supply in terms of calories. Analyzed together with the prevalence of undernourishment, it allows discerning whether undernourishment is mainly due to insufficiency of the food supply or to particularly bad distribution. The indicator is calculated in three year averages, from 1990-92 to 2014-16, to reduce the impact of possible errors in estimated DES, due to the difficulties in properly accounting of stock variations in major food. It thus provides an indicator of structural food supply adequacy (Source: Faostat - http://www.fao.org/faostat/en/#data/FS).