National Loaf
The National Loaf was a bread made from wholemeal flour with added calcium and vitamins, introduced in Britain during the Second World War by the Federation of Bakers (FOB). Introduced in 1942, the loaf (similar to today's brown bread) was made from wholemeal flour to combat wartime shortages of white flour and sugar. The loaf was abolished in October 1956.

Working with the government, the FOB published four recipes for wholemeal bread, which became the only recipes that could legally be used to make bread in the U.K. The National Loaf was grey, mushy and unappetising; only one person in seven preferred it to white bread, which became unavailable. The government insisted on it because it saved space in shipping food to Britain
and allowed better utilization of existing stocks of wheat. 

Eleanor Roosevelt, the American First Lady, visiting Buckingham Palace in 1942, noted that "We were served on gold and silver plates, but our bread was the same kind of war bread every other family had to eat."

See also

Rationing in the United Kingdom
Woolton pie

References

Further reading
 

British breads
United Kingdom home front during World War II