Rationing on a scientific basis was pioneered by Elsie Widdowson and Robert McCance at the Department of Experimental Medicine, University of Cambridge. They worked on the chemical composition of the human body, and on the nutritional value of different flours used to make bread. Widdowson also studied the impact of infant diet on human growth. They studied the differing effects from deficiencies of salt and of water and produced the first tables to compare the different nutritional content of foods before and after cooking. They co-authored "The Chemical Composition of Foods", first published in 1940 by the Medical Research Council. Their book "McCance and Widdowson" became known as the dietician's bible and formed the basis for modern nutritional thinking.