The Irish Diet as defined by FAO food balance statistics, was analysed in terms of calories consumed per capita per day for all major food groups and compared with the EAT-Lancet commission Planetary Health Diet in terms of GHG emissions, health index and cost. Food miles were also calculated for each food item, allowing calculation of the % contribution of imported foods in the Irish Diet in terms of calories consumed, and kgCO2 eq emitted. Daily calorific intake was calculated at 3695 kcals capita-1 day-1, with total GHG emissions calculated as 4.97 kg CO2 eq capita-1 day-1. In terms of calories consumed, imported foods made up 58% of daily per capita energy intake, but only contributed 10% of the total dietary GHG emissions. In all three respects related to sustainability – heath, cost, and reductions in GHG emissions, switching from our present pattern of calorie consumption to that recommended in the EAT-Lancet Diet is beneficial, increasing the health status of the diet by 90%, decreasing the cost of the diet by up to 36%, and decreasing per capita dietary GHG emissions by up to 65%.