Studies of infant mortality in both historical and modern populations from around the world have shown that the most important single factor affecting the infant mortality rate (IMR) is the way in which babies are fed. When methods of infant feeding are unsatisfactory or dangerous, mortality is high; when improvements are made in feeding practices, mortality falls, often dramatically, in a short period of time. The degree to which changes in infant feeding alone can affect IMRs depends on other factors in the population concerned, primarily the health and nutritional status of the mother; sanitary conditions both within the household and in the surrounding environment; levels of endemic and epidemic diseases; the degree of wealth, education and sophistication of the population; and, if women are employed outside the home, the provision made for infant feeding and care by the child's family and by society.

This article examines infant feeding practices in England during the first two decades of the twentieth century, arguably the most important 20 years in the fall in that nation's IMR between 1870 and 1920. The 1900s and 1910s saw many major changes in the ways in which infants were fed in all sections of society. Instigated by government, local Medical Officers of Health and their staff and voluntary organizations, the effect of the infant welfare movement in England in this period was that infants and their mothers were significantly better fed, cared for and able to resist disease in 1919 than in 1900.