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During the First World War food shortages were not a major problem on the home front until December 1916 when, in response to submarine warfare and growing shortages, a food controller was appointed. The resulting rise in food prices and queues caused industrial unrest in 1917 and 1918. After June 1917 government took control of home production and imports and rationing of sugar, fats and meat was introduced in 1918 and continued until 1920. The system was based on individual flat-rate rations, and each person had to register with a particular retailer who received supplies in proportion to registrations.

From the guide to the First World War Rationing Papers, 1917-1918, (Bangor University)