Until about thirteen years ago managers of Hudson's Bay Company posts in northern Canada chose from their trading stocks whatever foods they required for their families and staffs. In many instances their choice did not provide well-balanced meals. The Company had at that time become concerned about the frequency of illness at northern posts. This occasionally necessitated special mercy flights to bring patients south for medical care. In 1939, therefore, the Company consulted the late Dr F. F. Tisdall, who invited three of his colleagues, Dr T. G. H. Drake, Dr J. H. Ebbs and Dr E. C. Robertson, to assist him in the task of improving nutrition at northern posts. S. H. Jackson later joined the group.