1This Study of the nutrition of aircraft workers in California was sponsored by the Nutrition Committee (R. A. Millikan, Chairman), appointed by the Board of Supervisors of the County of Los Angeles, California, and the Committee on the Nutrition of Industrial Workers of the National Research Council. The Study was supported in part by the sponsors and by the following: the California Institute of Technology, The Lockheed Aircraft Corporation, the Milbank Memorial Fund, the War Production Board, and the Works Projects Administration (Project No. 12372). Support was also received from the California Fruit Growers Exchange, the Gelatin Products Corporation, Merck and Company, the National Oil Products Company, the Research Corporation, E. R. Squibb and Sons, and the Vita-Food Corporation. We wish to thank the officials of the Lockheed Aircraft Corporation who authorized the Study and who offered us every facility to carry it out. Their contribution was especially noteworthy in that the Study was made during the years of rapid expansion (1942-1943), under the heavy stress such activity implies. We are greatly indebted especially to Mr. Robert E. Gross, President; Dr. F. E. Poole, Medical Director, to whose department this Study was assigned; Mr. Dwight L. Palmer, Manager, Industrial Relations Research Division; Mr. L. Stockford, Analyst, who participated in the collection of data and in the preparation of preliminary reports; and to Mr. R. B. Robertson, Assistant Director of Industrial Relations. It is a pleasure to record the patient friendliness and cooperation extended us by the personnel of the divisions of Active Files and Inactive Files, and by the supervisorial staff in the plant. We wish to thank the local union (affiliated with the A. F. of L.), to which the workers belonged, for its approval of the Study and for its cooperation. We are indebted to Miss Dorothy G. Wiehl of the Milbank Memorial Fund for her searching criticism of the data in this report, for many valuable suggestions on the mode of presentation and assistance in the statistical analysis. We are indebted also to Miss Josephine Williams of the California Institute of Technology for her zeal and thoroughness in running down innumerable details in the Company records, and for her participation in the task of rechecking and tabulating all the data. We take this occasion, also, to thank Dr. Roger Stanton of the California Institute of Technology, who assisted us, as a volunteer, in every phase of the Study. 2 California Institute of Technology, Pasadena.