The first modern rationing systems were imposed during the First World War. In Germany, suffering from the effects of the British blockade, a rationing system was introduced in 1914 and was steadily expanded over the following years as the situation worsened. Although Britain did not suffer from food shortages, as the sea lanes were kept open for food imports, panic buying towards the end of the war prompted the rationing of first sugar and then meat. It is said to have benefited the overall health of the country, through the "levelling of consumption of essential foodstuffs". To assist with rationing, ration books were introduced on 1918 for butter, margarine, lard, meat, and sugar. During the war, average caloric intake decreased only three percent, but protein intake six percent.