three for dinner; fines were introduced for members of the public found feeding the pigeons or stray animals. In January 1917, Germany started unrestricted submarine warfare to try to starve Britain into submission. To meet this threat, voluntary rationing was introduced in February 1917. Bread was subsidised from September that year; prompted by local authorities taking matters into their own hands, compulsory rationing was introduced in stages between December 1917 and February 1918 as Britain's supply of wheat decreased to just six weeks' consumption. To help the process, ration books were introduced in July 1918 for butter, margarine, lard, meat, and sugar. Each consumer was tied to a retailer. The basic ration of sugar, butter or margarine, tea, jam, bacon and meat came to about 1,680 calories. It was adjusted for vegetarians, children and workers performing strenuous labour. Nutritional programmes for nursing mothers and young children were established by many local authorities. Unlike most of Europe bread was not rationed. It was argued that the civilian population's health improved under rationing, though tuberculosis increased. During the war, average energy intake decreased by only 3%, but protein intake by 6%. Controls were not fully released until 1921. General strike of 1926 The government made preparations to ration food in 1925, in advance of an expected general strike, and appointed Food Control Officers for each region. In the event, the trade unions of the London docks organised blockades by crowds, but convoys of lorries under military escort took the heart out of the strike, so that the measures did not have to be implemented. Second World War 1939–1945 Emergency supplies for the 4 million people expected to be evacuated were delivered to destination centres by August 1939, and 50 million ration books were already printed and distributed. When World War II began in September 1939, petrol was the first commodity to be controlled. On 8 January 1940, bacon, butter, and sugar were rationed. Meat, tea, jam, biscuits, breakfast cereals, cheese, eggs, lard, milk, canned and dried fruit were rationed subsequently, though not all at once. In June 1942, the Combined Food Board was set up by the United Kingdom and the United States to coordinate the world supply of food to the Allies, with special attention to flows from the U.S. and Canada to Britain. Almost all foods apart from vegetables and bread were rationed by August 1942. Strict rationing created a