Rationing was introduced into Britain at the tale end of World War One - in February 1918. Rationing was introduced in response to an effective U-boat campaign and during World War One, the Defence of the Realm Act (DORA) was used to ensure that food shortages never occurred. One of the primary aims of DORA, when it was first introduced, was to prevent food shortages. At the start of the war, food shortages were self-imposed as the German U-boat campaign had yet to start. However, at the start of the war people went around panic buying food and hoarding it at home. Some shops sold out of food in days in August 1914. However, after the initial panic buying, people settled down into a routine and food was not a problem until the end of 1916. Britain continued to import food during the war. The main exporters to Britain were America and Canada. This meant that merchant ships had to cross the Atlantic Ocean. Up to 1916, these merchant ships could travel in relative safety. However, in 1917, the Germans introduced unrestricted submarine warfare and merchant ships were sunk with great frequency. This had a drastic impact on Britain's food supply and with great losses in the Atlantic, food had to be rationed so that no-one starved in Britain. In April 1916, Britain only had six weeks of wheat left and bread was a staple part of most diets. 1916 was a bleak year for families - with the news from the Battle of the Somme and with food in short supply, suddenly the war was brought home to most families. Food prices rose and by October 1916, coal was in such short supply that it was rationed by the number of rooms a family had in its house. The restrictions introduced by DORA failed and the government then tried to introduce a voluntary code of rationing whereby people limited themselves to what they should eat. The standard was set by the Royal Family. However, this did not work. Those who worked in the munitions factories did not have enough food while anyone with money could get more than enough food on the black market. Any area that could grow food was converted to do so - gardens were turned into allotments and chickens etc. were kept in back gardens. The powers introduced by DORA empowered the government to take over land when it felt that it was necessary to do so. In 1917, the government took over 2.5 million acres of land for farming. By the end of the war, Britain had an extra three million acres of farming land. Those who would have usually worked the land - young men - had been called up, so the work was done by the Women's Land Army. Conscientious objectors also worked on the land. Despite the importance of the work done by the Women's Land Army, the government still felt that it was appropriate to warn them about the standards expected of them and their approach must have seemed very old fashioned to some: "You are doing a man's work and so you are dressed rather like a man; but remember that because you wear a smock and trousers you should take care to behave like an English girl who expects chivalry and respect from everyone she meets Despite the work by the WLA, the impact of the German U-boat campaign made food shortages a serious problem by 1918. Malnutrition was seen in poor communities and as a result the government introduced rationing in 1918. Food products were added to the list as the year progressed. In January 1918, sugar was rationed and by the end of April meat, butter, cheese and margarine were added to the list of rationed food. Ration cards were issued and everyone had to register with a butcher and grocer. Rationing was a clear indication to the British public that all was not well, but it did work.