<P> In January 1917, Germany started using submarines to sink all ships headed to Britain in an attempt to starve Britain into submission . To meet this threat to the food supply 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' worth . To facilitate the process, ration books were introduced in July 1918 for butter, margarine, lard, meat, and sugar . For the most part, rationing benefited the health of the country . During the war, average energy intake decreased only three percent, but protein intake six percent . </P> <P> 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 Trades Unions of the London docks organized 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 . </P> <P> After the Second World War began in September 1939 the first commodity to be controlled was petrol . On 8 January 1940 bacon, butter and sugar were rationed . This was followed by successive ration schemes for meat, tea, jam, biscuits, breakfast cereals, cheese, eggs, lard, milk, and canned and dried fruit . In June 1942 the Combined Food Board was set up 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 inevitably created a black market . Almost all controlled items were rationed by weight but meat was rationed by price . </P> <P> Fresh vegetables and fruit were not rationed but supplies were limited . Some types of imported fruit all but disappeared . Lemons and bananas became unobtainable for most of the war; oranges continued to be sold but greengrocers customarily reserved them for children and pregnant women, who could prove their status by producing their distinctive ration books . Other domestically grown fruit such as apples still appeared from time to time, but again the sellers imposed their own restrictions so that customers were often not allowed to buy, for example, more than one apple each . Many people grew their own vegetables, greatly encouraged by the highly successful digging for victory motivational campaign . In 1942 numerous children between five and seven years old had become used to wartime restrictions . When questioned about bananas, many did not believe such items existed . Game meat such as rabbit and pigeon were not rationed but were not always available . A popular music - hall song, written 20 years previously but sung ironically, was "Yes! We Have No Bananas". During the food rationing, British biologists ate laboratory rat . </P>

When did rationing start in britain during world war 2