The effects on diet of the Great War differed considerably from prewar expectations, since neither the length of the conflict nor the effectiveness of the submarine campaign against merchant shipping had been envisaged by politicians and civil servants. For the first two years of hostilities against the Central Powers there were bumper harvests, and supplies were sustained by normal trade conditions. However, in view of the fact that the greater part of Britain's foodstuffs was imported, the lack of planning was a hazardous strategy, particularly since the supply of ‘the very narrow range of staples eaten by the working classes’ (i.e. bread, sugar, lard, cheese, bacon, condensed milk and meat) was at risk:

The lack of intervention by Walter Runciman, President of the Board of Trade from 1914 to 1916, to control food supplies was consistent with his ‘Free Trade’ principles and the Liberal government's general philosophy, but it prevented any coherent food policy from developing. The regulation of the food market therefore occurred in an ad hoc manner: the Home Secretary effected control of the sugar trade on 7 August 1914, by establishing a Royal Commission; from October 1914, the War Office requisitioned large imports of meat, especially frozen meat, to ensure the army's needs were met. In January 1915, there were five committees discussing various aspects of food supply, including, nominally, a Cabinet Committee on Food Supplies. From February 1915, when the German naval command adopted unrestricted attacks on merchant shipping, the growing success of German submarines and the increasing demands upon British shipping forced change. By 1917, U-boats had sunk 2M tons of Britain's merchant fleet. However, with one-third of Britain's ships engaged in supplying the armed forces abroad and one-fifth on loan to the Allies, only one-third was available for the home supply trade, including food.