"Remember that there were no in the 1920's, and every had to depend on a few recognized authorities for estimates of needs of children. In 1923, called attention ... to the protein needs for optimal growth in rats which he estimated to be about 15 per cent of the calories. He contrasted that with which provides only 7 per cent of the calories in the form of protein, to provide for the growth of the infant. He also emphasized what and had demonstrated earlier that animal proteins were more efficient for growth than plant proteins."