 An essential ingredient for the successful execution of the Minnesota Starvation Experiment was the availability of a sufficient number of healthy volunteers willing to subject themselves to the year-long invasion of privacy, nutritional deprivation and physical and mental hardship necessary to complete the study.From the outset, the experiment was planned in cooperation with the Civilian Public Service and the Selective Service System, with the intention of using volunteers selected from the ranks of conscientious objectors already inducted into public wartime service.Keys obtained approval from the War Department to select participants from the CPS.