The goal is based on the idea of food security, by which a country should endeavor to ensure the minimum necessary supply of food in case of poor harvests at home or abroad caused by such factors as abnormal weather conditions, or in case of an unexpected situation, such as a state of war.
Japan is the first developed country to set a numerical target for food self-sufficiency.
From now on the government will make all-out efforts to increase the production of agricultural and other products. Although there are several ways of measuring the food self-sufficiency rate, it is usually calculated on a calorific supply base. Different foods, such as grain, vegetables, and meat, are converted into the common measure of energy, or calories, and the ratio that can be supplied domestically is calculated. Also, the government has set production and self-sufficiency targets by product. Since then, however, the rate has continued almost constantly on a downward trend, dropping nearly 40 percentage points over four decades.