713 
 
 U. S. DEPARTMENT OF AGRICULTURE. 
 
 OFFICE OF EXPERIMENT STATIONS, 
 I A. C. TRUE, Director. 
 
 INVESTIGATIONS 
 
 NUTRITION OF MAN 
 
 IN THE 
 
 UNITED STATES. 
 
 C. F. LANGWORTHY, Ph. D., and R. D. MILNER, Pii. B. 
 
 Of the Office of Experimeni Statiom^. 
 
 WASHINGTON: 
 
 GOVERNMENT PRINTING OFFICE. 
 1904. 
 
LIST OF PUBLICATIONS OF THE OFFICE OF EXPERIMENT STATIONS ON 
 THE FOOD AND NUTRITION OF MAN. 
 
 E. — For those publications to which a price is aflixoil application should be made to the Super- 
 lent of Documents, Government Printing Office, Washington, I). C, the oflflcer designated by 
 
 KOTE.- 
 
 intenden 
 
 law to sell Government publications. Publications marked with an asterisk (*) are not available for 
 
 distribution. 
 
 ♦Charts. Food and Diet. By W. O. Atwater. (Four charts, 26 by 40 inches.) Price per set, 
 
 unmounted, 75 cents. 
 *Bul. -Jl. Methods and Results of Investigations on the Chemistry and Economy of Food. By W. O. 
 
 Atwater. Pp. 222. Price, 15 cents. 
 Bui. 2S. (Kevisud edition.) The Chemical Composition of American Food Materials. By W. 0. 
 
 Atwater and A. P. Bryant. Pp. 87. Price, 5 cents. 
 Bui. 29. Dietary Studies at the University of Tennessee in 1895. By C. E. Wait, with comments by 
 
 W. ()! Atwater and C. D. Woods. Pp. 45. Price, 5 cents. 
 Bui. 31. Dietary Studies at the University of Missouri in 1895, and Data Relating to Bread and Meat 
 " Con.-i'umption in Missouri. By H. B. Gibson, S. Calvert, and D. W. May, witli comments by 
 
 W. O. Atwater and C. D. Woods. Pp. 24. Price, 5 cents. 
 *Bul. 32. Dietary Studies at Purdue Univensitv, Lafayette, Ind., in 1895. By W.E.Stone, with com- 
 ments bv W. O. Atwater and C. D. Woods. Pp. 28. Price, 6 cents. 
 Bui. 35. Food and Nutrition Investigations in New Jersey in 1895 and 1890. By E. B. Voorhees. Pp. 40. 
 
 Price, 5 cents. 
 
 * Bui. 37. Dietary Studies at the Maine State College in 1895. By W. H. .Jordan. Pp. 57. Price, 5 cents. 
 
 Bui. 3H. Dietary Studies witli Reference to the Food of the Negro in Alabama in 1.895 and 1S96. Con- 
 ducted with the cooperation of the Tuskegee Normal and Industrial Institute and the Agri- 
 cultural and Mechanical College of Alabama. Reported by W. O. Atwater and C. D. Woods. 
 Pp. 69. Price, 5 cents. 
 
 Hul. 10. Dietary Studies in New Mexico in 1895. ByA. Goss. Pp.23. Price, 5 cents. 
 
 Bui. 13. Losses'in Boiling Vegetables and the Composition and Digestibility of Potatoes and Eggs. 
 
 By. H. Snyder, A. .7. Frisby, and A. P. Bryant. Pp. 31. Price, 5 cents. 
 Bui. 41. Report of Preliminary Investigations on the Metal)olism of Nitrogen and Carbon in the 
 
 Human Organism with a Respiration Calorimeter of Special Construction. By W. O. 
 
 Atwater, CD. Woods, and F. G. Benedict. Pp. 64. Price, 5 cents. 
 Bui. 15. A Digest of Metabolism Experiments in which the Balance of Income and Outgo was 
 
 Determined. By W. O. Atwater and C. F. Laugworthy. Pp. 434. Price,- 25 cents. 
 *Bul. 16. Dietary Studies in New York City in 1895 and 1896. By W. O. Atwater and C. D. Woods. 
 
 Pp. 117. Price, 10 cents. 
 Bui. .52. Nutrition Investigations in Pittsburg, Pa., 1894-1896. By Isabel Bevier. Pp. 48. Price, 
 
 5 cents. 
 Bui. .53. Nutrition Investigations at the University of Tennessee in 1896 and 1897. By C. E. Wait. 
 
 Pp. 10. Price, 5 cents. 
 *Bul. 54, Nutrition Investigations in New Mexico in 1897. By A. Gos.s. Pp.20. Price, 5 cents. 
 Bui. 65. Dietary Studies in Chicago in 1S95 and 1896. Conducted with the cooperation of Jane 
 
 Addams and Caroline L. Hunt, of Hull House. Reported by W. O. Atwater and A. P. 
 
 Bryant. Pp.76. Price, Scents. 
 
 * Bui. ,56. His'tory and Present Status of Instruction in Cooking in the Public Schools of New York 
 
 City. "Reported by Mrs. Louise E. Hogan, with an introduction by A. C. True, Ph.D. 
 Pp. 70. Price, 5 cents. 
 Bui. 63. Description of a New Respiration Calorimeter and Experiments on the Con.servation of Energy 
 in the Human Body. By W. O. Atwater and E. B. Rosa. Pp. 94. Price, 10 cents. 
 
 * Bui. 6C. The Physiological KiTect of Creatin and Creatinin and their Value as Nutrients. By J. W. 
 
 Mallet. Pp.24. Price, 5 cents. 
 Bui. 67. Studies on Bread and Bread Making. By Harry Snyder and L. A. Voorhees. Pp. 51. Price, 
 
 10 cents. 
 Bui. 68. A Description of Some Chinese Vegetable Food Materials and Their Nutritive and Economic 
 
 Value. By W. C. Blasdale. Pp. 48. Price, 10 cents. 
 B)il. 69. Experiments on the Metabolism of Matter and Energy in the Human Body. By W. O. 
 
 Atwaterand F. G. Benedict, with the cooperation of A. W. Smithand A. P. Bryant. Pp.112. 
 
 Price, 10 cents. 
 Bui. 71. Dietary Studies of Negroes in Eastern Virginia in 1897 and 1898. By H. B. Frissell and Isabel 
 
 Bevier. Pp. 45. Price, 5 cents. 
 Bui. 7.5. Dietary Studies of University Boat Crews. By W. 0. Atwater and A. P. Bryant. Pp. 72. 
 
 Price, 5 cents. 
 Bui. 84. Nutrition Investigations at the California Agricultural Experiiment Station, 1896-1898. By 
 
 M. E. Jaffa. Pp. 39. Price, 6 cents. 
 Bui. 85. A Repr)rt of Investigations on the Digestibility and Nutritive Value of Bread. By C. D. 
 
 Woods and L. H. Merrill. Pp. 51. Price, 5 cents. 
 
 [Continued on third page of cover.] 
 
U. S. DEPARTMENT OF AGRICULTURE, 
 
 l\.S. OFFICE OF EXPERIMENT STATIONS, 
 
 A. C. TRUE, Director. 
 
 1 
 
 INVESTIGATIONS 
 
 NUTRITION OF MAN 
 
 IX THE 
 
 UNITED STATES. 
 
 BY 
 
 C. F. LANG WORTHY, Ph. D., and R. D. MILNER, Ph. B., 
 
 OJ tlie Office of Exjie7'i7nen1 Staticnts. 
 
 WASHINGTON: 
 
 GOVEKNMENT PRIXTIXG OFFICE. 
 19 04-.; 
 
 6^^ 
 
 > ,' 3 3 3 3 
 
OFFICE OF EXPERIMENT STATIONS. 
 
 A. C. True, Ph. D., Director. 
 
 E. W. Allen, Ph. D., Assistant Director and Editor of Kvperime)tt Statio)i Record. 
 
 C. F. L.\X(;woRTHY, Ph. I)., Editor and Expert on Foods and Aiiimal Production. 
 
 NUTRITION INVESTIG.\TIONS. 
 
 W. O. Atwater, Ph. D., Chief of Xulrition Invesiif/ations, Middletovn, Conn. 
 
 C. D. Woods, B. S., Special Agent at Orono, Me. 
 
 F. G. Benedict, Ph. D., PlHjdological Chemist, Middleiown, Conn. 
 
 R. D. INIiLNER, Ph. B., Editorial Assistant, MiddJetoicn, Conn. 
 
LETTER OF TRANSMITTAL. 
 
 U. S. Department of Agriculture, 
 
 Office of Experiment Stations, 
 
 Washington^ D. 6'., May 25^ 190 Jf.. 
 Sik: I have the honor to transmit herewith and recommend for pub- 
 lication a summary showing- the scope of the cooperative nutrition 
 investigations carried on under the auspices of this Otiice. This 
 includes an account of the origin and development of the investiga- 
 tions and their character, data regarding the collaborators and collab- 
 orating institutions, and also some of the more important results 
 obtained. 
 
 Respectfully, A. C. True, 
 
 Dinctor. 
 Hon. James Wilson, 
 
 Sccreta ry of A <j rlcult u re. 
 
CONTENTS. 
 
 Introduction 
 
 Organization of the in(|uiry 
 
 Scope of the incjiiiry 
 
 Distribution of tlie work 
 
 Some results of nutrition investigations 
 
 Composition of food materials 
 
 Dietary studies 
 
 Digestion experiments 
 
 Metabolism experiments with the respiration calorimeter 
 
 Factors for digestibility and fuel value of nutrients 
 
 The pecuniary economy of food 
 
 The educational influence of the nutrition investigations 
 
 Conclusion 
 
 Page. 
 
 8 
 10 
 12 
 12 
 13 
 10 
 16 
 17 
 18 
 19 
 20 
 
 ILLUSTRATIONS. 
 
 Plate I. Fig. 1. — Bread from normal tiour and from mixtures of normal and 
 extracted flours. Fig. 2. — Bread from normal flour and from 
 
 mixtures of normal and corn flours 8 
 
 II. Composition of food inaterials 12 
 
 III. Dinner at a Chiuese truck farm, California 12 
 
 IV. ( ieneral view of the respiration calorimeter 16 
 
 V. (iround plan of respiration calorimeter laboratory 16 
 
 VI. Pecuniary economy of food 18 
 
 4 
 
INVESTIGATIONS ON THE NUTRITIOX OF MAN IN THE 
 UNITED STATES. 
 
 By C. F. Lang WORTHY, Ph. D., and R. D. Milxer, Ph. B., 
 
 Of the Office of Experiment Stations. 
 
 INTRODUCTION. 
 
 During- the past few years the experimental study of the food and 
 nutrition of both dome.stie animals and man has become verj^ active in 
 the United States. A large part of such inquiry, indeed nearly all of 
 that which has to do with domestic animals, is carried on in connec- 
 tion with the agricultural experiment stations, which have been estab- 
 lished within the past twenty-eight years and are now in operation in 
 all the States and Territories of the Union except the Philippines. 
 
 With the rise of the experiment stations inquiries into the composi- 
 tion of feeding stutfs and their appropriate use in the nutrition of 
 domestic animals were undertaken, and have ever since been carried 
 on quite actively. Later some of the stations undertook similar inves- 
 tig'ations of tlie food of man, and in recent years the study of the food 
 and nutrition of man has acquired increased importance in the United 
 States from the extensive investigations that have been made and are 
 still being made in connection with and as a part of the work of the 
 Department of Agriculture in cooperation with universities, colleges, 
 experiment stations, benevolent institutions, and individual investi- 
 gators in different parts of the country. 
 
 There had been, indeed, a considerable amount of study of the food 
 of man — and of domestic animals also — before the experiment stations- 
 were established. An interesting investigation on the subject of 
 human nutrition was prosecuted b}- J. R. Young, in Philadelphia, as 
 early as 1803, and perhaps almost continuously since that time vaki- 
 able information on food and nutrition has been accumulated by phy- 
 sicians, by State boards of health, and b}^ .specialists in physiology, 
 hygiene, and dietetics. The United States Government, through its 
 various branches, has contributed much of value to the science of 
 nutrition. The War Department and the Navy Department, in their 
 efforts to secure the most satisfactory diet for the soldiers and sailors, 
 have collected a great deal of information and conducted man}^ inves- 
 tigations which have to do with the subject of dietetics, while the 
 
 5 
 
6 
 
 importance of their investigations dealing- with the hygiene of the 
 subject can hardl}' be overestimated. In connection with the United 
 States Census a large amount of data regarding foods has been 
 secured, the major portion of which has to do with production and 
 distribution, though man}' analyses have been reported in census pub- 
 lications, as well as special studies of foods, food industries, and 
 related topics. Of ver^^ noteworthy importance are the studies of 
 analytical methods, of the chemical composition of foods, and of food 
 adulteration, conducted in the Bureau of Chemistry of the Department 
 of Agriculture by its chief. Prof. H. W. Wiley, and others. 
 
 A complete historical review of investigations on food and nutrition 
 of man in the United States would necessarily include an account of 
 the above inquiries and others not referred to here. The purpose of 
 the present article, however, is to give a brief resume of the coopera- 
 tive inquiry into the food and nutrition of man now being carried on 
 under the auspices of the Office of Experiment Stations of the Depart- 
 ment of Agriculture, and to indicate the progress and results of that 
 enterprise. This inquiry had its inception in a studv of the chemical 
 composition of food fishes and invertebrates undertaken bv Prof. 
 W. O. At water in 1877 and continued until 1882, in the chemical labora- 
 tory of Wesleyan University, Middletown, Conn., at the instance of 
 Prof. S. F. Baird, Secretar}' of the Smithsonian Institution and United 
 States Commissioner of Fish and Fisheries. In connection with this 
 work similar investigations of other animal and some vegetable prod- 
 ucts were undertaken a little later (1884) on behalf of the United 
 States National Museum. About the same time (1886) the first 
 extended inquiry into the statistics of food consumption in the United 
 States was undertaken b}' Hon. Carroll D. Wright, as chief of the 
 Massachusetts Bureau of Statistics of La])or, and the chemical results 
 were computed and reported b}- Professor At water. In 1890 the 
 Connecticut (Storrs) Experiment Station, under the direction of Pro- 
 fessoi" Atwater, in cooperation with Hon. Carroll I). Wright as United 
 States Commissioner of Labor, began a series of dietarj- studies which 
 continued for several A^ears. Except for the inquiries under the aus- 
 pices of the Massachusetts lal)()»- bureau, the United States Department 
 of Labor, and the Connecticut (Storrs) Experiment Station, the larger 
 share of the expenses of this work w'as borne by private individuals. 
 The results of these iiupuries gradually attracted attention. The 
 bearing of such research upon household, agricultural, and national 
 economics became evident, and as early as 1890 steps were taken to 
 secure an appropriation fi'om Congress to enlarge its scope and use- 
 fulness, ))ut nothing definite was accomplished there until 1891. In 
 that j'ear the experiment stations were authorized by Congress to 
 cooperate with the Secretary of Agriculture in studying the food and 
 nutrition of man, and were called upon to report to him the results of 
 
 « 
 
 II 
 
such investigations as they might cany out. At the same time Con- 
 gress provided an especial appropriation to enable the Secretary of 
 Agriculture to prosecute inquiries in this direction. The sums pro- 
 vided by Congress for nutrition investigations for the Department of 
 Agriculture have been since the beginning: 
 
 
 Fiscal 
 
 year. 
 
 Amount. 
 
 
 Fiscal 
 
 year. • 
 
 Amount. 
 
 1894-95 .... 
 
 
 
 SIO, 000 
 15, 000 
 15. 000 
 15,000 
 15, 000 
 15,0C0 
 
 1900-1901 
 
 1901-2 . . - - - - --^ 
 
 S17, 500 
 20, 000 
 
 189fi-97 
 
 jxq7 Q8 
 
 1902-3 
 
 1903-4 
 
 
 
 20, 000 
 20 000 
 
 1898-99.... 
 1899-1900 
 
 1904-5 
 
 
 
 20. 000 
 
 
 
 
 
 These amounts have been increased by contributions from other 
 sources which are not easily estimated in terms of mone\% since they 
 consist in large part of the use of laboratories, apparatus, and other 
 facilities for research, the counsel and help of experts, and other gra- 
 tuitous service. The State of Connecticut makes an annual appropri- 
 ation, which is used under Professor Atwater's direction, for nutrition 
 investigations, in cooperation with the United States Department of 
 Agriculture. Part of the appropriation made liy the State of Illinois 
 to its State University and experiment station is regularly expended 
 in the study of problems related to the food and nutrition of man. A 
 considerable number of other experiment stations, educational institu- 
 tions, philanthropic organizations, and private individuals have given 
 sums of money to promote the cooperative inquiry. 
 
 ORGANIZATION OF THE INaUIRY. 
 
 The nutrition investigations of the Department of Agriculture are 
 conducted through the Office of flxperiment Stations, the general 
 supervision of these investigations having been assigned 1)}^ the Sec- 
 retary of Agriculture to that Office. The immediate supervision of 
 the enterprise has ])een entrusted to Prof. "W. O. Atwater. chief of 
 nutrition investigations. 
 
 For many years I'rofessor Atwater, in connection with his duties as 
 professor of chemistiy at We.sle3an University, has devoted much of 
 his time to investigations relating to the nutrition of man, introducing 
 into the United States the German methods of studying nutrition 
 problems. He was the iirst director of the Office of Experiment Sta- 
 tions, and, after his services in this capacity had terminated, the Depart- 
 ment was veiy fortunate in securing his cooperation as special agent 
 in charge of its nutrition investigations. The very great development 
 of this enterprise, as evidenced by the numl)er and extent of the inves- 
 tigations carried on, the public interest which has been arou.sed, the 
 demand for information from private individuals, physicians, and 
 teachers, and the practical application of the results already obtained 
 
in numerous instances where rational and economical feeding- was 
 a necessity, are indications that the investigations have been well 
 managed. 
 
 The administrative and editorial work connected with the nutrition 
 investigations is conducted at Washington, D. C, and Middletown, 
 Conn. The investigations themselves are prosecuted in different 
 places, the general policv being to make particular institutions centers 
 of iuA'estigations along special lines. Part of the fund provided b}" 
 Congress is expended under the sole and immediate care of the Depart- 
 ment; part is distributed among scientific, educational, and philan- 
 thropic institutions in various places from Maine to California, and 
 used not so nuich as compensation for services as for encouragement 
 to research. The cooperating institutions have in most cases contrib- 
 uted material assistance, especially as regards laboratory rooms and 
 appliances and the services of skilled investigators. 
 
 SCOPE OF THE INaUIRY. 
 
 Investigations on the food and nutrition of man include the study 
 of two branches of the subject, which, though quite intimately related 
 and both A^aluable, are nevertheless of importance in different ways. 
 One branch comprises a study of the chemical composition of dif- 
 ferent food materials, an investigation that is purely anal3"tical, but a 
 necessarj'^ preliminary to studies in the other branch of the subject, 
 which comprises researches into the laws of nutrition. The former is 
 concerned simply with the chemistry of food, while the latter has to 
 do with the physiology, the~ph3^sics and chemistry, of the nutrition of 
 man, together with the economic and sociological application of the 
 fundamental principles of nutrition to the diet of persons in different 
 localities and under different conditions in life. 
 
 The cooperative nutrition investigations include studies of several 
 branches of the subject, especial attention having been paid to studies 
 of the kinds and amounts of food consumed by individuals, families, 
 institutions, etc.; experiments on the digestibditv of food materials; 
 and researches into the fundamental laws of nutrition, including par- 
 ticularly investigations with the bond) calorimeter and the respiration 
 calorimeter. In addition to these, collateral questions of a wide 
 variety have also received much attention. A brief statement of the 
 general lines along which the inquiries have been conducted is as 
 follows: 
 
 Studies of acUial dietaries in order to learn the kinds, anidunts, antl costs of food 
 materials consumed by persons in different localities, of different occupations, ages, 
 and sex, and under varying conditions. 
 
 Special studies of cereal j^rodurts, including nutritive value of different milling 
 products of wheat; nutritive value, quality, and digestibility of bread from hard and 
 soft wheat flours of different grades, as "graham," "entire wheat," and 'standard 
 patent" grades; bakery experiments to determine the cost of making bread, and the 
 
U. S. Dept. of Agr., Office of Expt. Stalions, 713. 
 
 Plate I. 
 
 Fig. 1 .—Bread from Normal Flour and from Mixtures of Normal and 
 Extracted Flours. 
 
 A, Normal flour; B, flour witli iibout one-half of the gliadin extracted: (', one-half normal and 
 one-half gliadin-extracted flour. 
 
 FiQ. 2.— Bread from Normal Flour and from Mixtures of Normal and Corn 
 
 Flours. 
 
 A, Normal flour; B, normal flour and '20 per cent corn flour: C, normal flour and 10 per cent 
 
 corn flour. 
 
9 
 
 looses in nutritive value during the process of bread making. Plate I illustrates 
 the results obtained in some of these studies of the effect and the importance of the 
 various constituents of flour upon the character of the bread. In fig. 1, bread A 
 was made from normal fiour and breads B and C from flour which contained abnor- 
 mal amounts of gliadin, one of the important nitrogenous constituents of flour. In 
 fig. 2, A represents normal bread and B and C bread made from flour in which the 
 starch content was rendered abnormal ))y adding corn flour. 
 
 Special studies of meats, including the nutritive value of raw and cooked meats; 
 the relative digestibility of meats cooked in different ways; the nature and amount 
 of losses occurring during the cooking of meats in different ways. 
 
 Experiments on the digestibility of vegetal)les and the losses in different vegetal)les 
 during cooking. 
 
 Experiments on the digestibility and nutritive value <>f legumes, including ])eans 
 and cowpeas. 
 
 Studies of the comparative econoniy, digestibility, and nutritive value of fruits and 
 nuts. 
 
 A convenient and comparatively inexpensive form of bomb calorimeter has been 
 developed and is used in determining the amounts of potential energy in food mate- 
 rials, excretory products, and other substances. 
 
 Metabolism experiments have l>een carried on with men in the respiration calo- 
 rimeter. The oV)jects of these investigations have lieen: To develop an apparatus 
 and method for the accurate measurement of the income and outgo of the animal 
 organism as expressed in terms of matter and energy; to confirm the belief that the 
 law of the conservation of energy obtains in the living body; and, after such demon- 
 stration of the accuracy of the apparatus and methods and of the action of the law of 
 the conservation of energy, to study some of the more important fundamental laws 
 of nutrition. 
 
 The fact was early recognized that compilations and summaries of the investiga- 
 tions which have been carried on in Europe and this country were neces.sary. In 
 order to conduct any kind of research most efficiently it is necessary to know what 
 has been accomplished by others in order that the investigator may profit by their 
 results and that an unnecessary duplication of effort may Ije avoided. Furthermore, 
 summaries of previous investigations are of great value in suggesting lines of research 
 and in awakening the interest of investigators by showing past achievements. To 
 this end the current literature of the nutrition of man, w-hich is now quite volumi- 
 nous, is being regularly followed up, and such abstracts and compilations are being 
 made as will promote the intere.st of the investigations. 
 
 The rapid accumulation of material which must l)e made ready for publication 
 necessitates a large amount of editorial work. The results of the investigations are 
 given in bulletins, some of popular nature and others technical in character. The 
 results of analyses of food materials in the United States have been compiled and 
 printed m a bulletin for popular use, Avhich is revised from time to time as data 
 accumulate. The results of dietary studies also appear in bulletins prepared for 
 popular use. The data of the digestion experiments and those obtained in investi- 
 gations with the respiration calorimeter are given in bulletins more or less technical 
 in character, and intended rather for the scientific student of the subject. Abstracts 
 of the current literature of the subject of food and nutrition appear regularly in the 
 Experiment Station Record. More popular abstracts of some of this work, particu- 
 larly that of American investigators, appear in the series of Farmers' Bulletins, 
 entitled "Experiment Station Work." 
 
 The correspondence connected with the nutrition investigations has grown to very 
 considerable dimensions. 
 
10 
 
 DISTRIBUTION OF THE WORK. 
 
 The following is a brief snmmaiy, alphabeticalh' bj' States, of the 
 localities in which the inquiries have been prosecuted, the cooperating 
 institutions and investigators, and the nature of the investigations 
 conducted : 
 
 Alahmna. — Tnskegee Normal and Agricultural InstiUite; Prof. Booker T. Wash- 
 ington. Alabama Polytefhnic Institute and the Alabama Experiment Station, 
 Auburn; Prof. B. B. Ross. Study of the food consumption of the negroes in the 
 "black belt" of Alabama, and of the character and nutritive value of the food 
 materials used by negroes. 
 
 California. — University of California; Prof. M. E. Jaffa. Cost and nutritive value of 
 California food materials, especially fruits and nuts; dietary studies of infants, 
 athletes, professional men, fruitarians, and Chinese; digestion and nitrogen meta- 
 bolism experiments with an infant and with fruitarians. 
 
 In addition, INIr. W. C. Blasdale, instructor in chemistry at the university, made a 
 detailed study of the nutritive and economic value of Chinese vegetal)le food materials 
 found in the markets of San Francisco. 
 
 Comiedicut. — Wesleyan University and Storrs Experiment Station; Prof. W. O. 
 Atwater, Prof. F. G. Benedict, and associates. Cost and nutritive value of various 
 food materials; dietary studies; digestion and nitrogen metabolism experiments; 
 development of bomb calorimeter and respiration calorimeter, and of methods of 
 using these in investigations of the metabolism of matter and energy in the human 
 body. 
 
 The work of the office of Professor Atwater, who is chief of the nutrition investi- 
 gations, has also included the planning and direct supervision of the cooperative inves- 
 tigations in different parts of the country, the compilation of the results of nutrition 
 investigations in the United States and foreign countries, editorial work in the prepa- 
 ration of the reports of the eooperators for publication, and a large correspondence 
 relating to the investigations. 
 
 Georgia. — University of Georgia; Dr. H. C. White. Dietary studies of t-ollege 
 boarding, clubs, and of families in the mountain regions of Georgia. 
 
 Illinois. — Hull House, Chicago; ISIi.ss Jane Addams and ISIiss Caroline Hunt; and 
 Lewis Institute, Chicago; Prof. G. N. Carman. Dietary studies. 
 
 ]Mrs. Ellen H. Richards and Mi.ss Amelia Shapleigh also carried on dietary studies 
 with the cooperation of Hull House. The data obtained were eventually submitted 
 to the Department of Agriculture for calculation and publication. 
 
 University of Illinois; Prof. H. S. Grindley. Cost and nutritive value of food 
 materials; dietary studies: special investigations on meat, including losses in different 
 modes of cooking, and digestibility of meats cooked in different ways. Prof. Isabel 
 Bevier and Miss Elizabeth Sj)rague. Studies in cooking meat. • 
 
 Indiana. — Purdue University; Prof. W. E. Stone. Dietary studies. 
 
 Maine. — University of Maine and ]\Iaine p]xi)eriment Station; Prof. W. H. Jordan, 
 Prof. C. D. AVoods, and L. H. Merrill. Studies of the nutritive value of a number 
 of food materials; feeding experiments to determine the value oi milk in the diet; 
 and dietary studies and digestion experiments, especially with lumbermen in the 
 Maine woods. Experiments on the digestibility and nutritive value of bread made 
 from different grades of flour; study of experimental methods, particularly means of 
 separation of feces in digestion experiments and determination of metabolic nitrogen 
 in feces. 
 
 Maniknah — Mrs. Mary Hinnian Abel cooperated with the D('i)artiuent in the 
 l)rei)aration of summaries of data regarding the nutritive value and ]>]ace in theMiet 
 of sugar and of leguminous vegetables, and in connection with this work made a 
 number of cooking experiments. 
 
11 
 
 ^fassac)^vselt.t. — School of Housekeeping, Boston; Miss Lydia Southard, Miss 
 Susannah Usher, and INIiss Bertlia M. Terrill carried on dietary studies, in a number 
 of which the attempt was made to regulate»the cost of the food and at the same time 
 make it compare with commonly accepted dietary standards. The results of these 
 investigations were submitted to the Department for calculation and publication. 
 
 Harvard University, Cambridge; Dr. E. A. Darling. Dietary studies of athletes. 
 Prof. C. R. Sanger and Mr. Edward INIallinckrodt, jr. Dietary studies of students. 
 
 Springfield Bible Normal College; Miss Bertha M. Terrill. Dietary study. In 
 this investigation the attempt was made to regulate the cost of the daily food and at 
 the same time make it correspond with the connnonly accepted dietary standards. 
 The results were submitted to the Department for calculation and publication. 
 
 Minnesota. — University of Minnesota and Minnesota Experiment Station; Prof. 
 Harry Snyder. Study of losses in cooking vegetables and in making bread; special 
 studies of cereal products, including relative nutritive value of milling products of 
 wheat, and digestibility and nutritive value of bread made from different grades of 
 hard and soft wheat flours. A considerable part of the latter investigation is carried 
 on coordinately with similar work by Prof. C. D. Woods at the Maine Experiment 
 Station. 
 
 Missouri — University of Missouri; Prof. H. B. Gibson. Dietary studies; inve.sti- 
 gation of the relative consumption of different kinds of meat and liread. 
 
 New Jersey. — New Jersey Experiment Station; Prof. E. B. Voorhees and Mr. L. A. 
 Voorhees. Dietary study; studies of the cost and comijosition of milk and of bread, 
 of the relative cost of bread and the raw ingredients from which it was made, and of 
 the losses in baking bread. 
 
 Neiv Mexico. — New Mexico College of Agriculture and Mechanic Arts and New 
 Mexico Experiment Station; Prof. Arthur Goss. Stu<ly of the relative nutritive 
 value of native food materials, especially native beef, and of the food consumption of 
 native Mexican families. 
 
 New York. — -Mrs. Louise E. Hogan studied the history and methods of teaching 
 cookery in the public schools of New York City. 
 
 Cornell University, Ithaca; Prof. R. C. Carpenter. Mea.surements of mechanical 
 work, and studies of the efficiency of man as a machine. 
 
 New York Association for the Improvement of the Condition of the Poor and New 
 York Christian Alliance, New Y''ork; Dr. Isabelle Delaney. Dietary studies of poor 
 families in congested districts in New York City. 
 
 Columbia University, New Y^ork; Dr. H. C. Sherman. Digestion experiments and 
 investigations on the metabolism of nitrogen, sulphur, and phosphorus in the human 
 ])ody. 
 
 North Dakota. — North Dakota Agricultural College; Prof. E. F. Ladd. Dietary 
 study. 
 
 Ohio. — Lake Erie College; Prof. Isabel Bevierand ^liss Elizabeth Sprague. Dietary 
 study. 
 
 Pennsylvania.— College Settlement, Philadelphia; Mrs. Ellen H. Richards and Miss 
 Amelia Shapleigh. Dietary studies of families of limited income Avere undertaken, 
 the data obtained being submitted to the Department for calculation and publication. 
 
 Pennsylvania College for Women, Pittsburg; Prof. Isabel Bevier. Dietary studies; 
 study of the composition and cost of bakers' liread in Pittsburg and of the changes 
 in the materials of bread during baking. 
 
 Tennessee. — University of Tennessee; Prof. C. E. Wait. Analyses of Tennessee 
 food materials; dietary studies; experiments on the effect of muscular work ujion 
 the digestibility of food and the metabolism of nitrogen; studies of the digestibility 
 and nutritive value of legumes. 
 
 T>rmo»/.— Vermont Experiment Station; Prof. J. L. Hills. Dietary studies of 
 farmers' families. 
 
12 
 
 Virginia. — Hampton Normal and Agricultural Institute; Dr. H. B. Frissell. Dietary 
 studies of negroes. 
 
 Under special authorization Miss Isabel Bevier also made similar studies in another 
 part of the State. 
 
 State University; Prof. J. W. ^Mallett. Studies uf the physiological effects of meat 
 bases, i. e., creatin and creatinin. 
 
 Washington, D. C. — Besides the general supervision vi the plans and expenditures, 
 the work of the Washington office in relation to the nutrition investigations has 
 included the preparation of popular bulletins; the compilation of technical summa- 
 ries of investigations; editorial work in perfecting the details of reports of investiga- 
 tions; collection of bibliographical data; the abstracting of the literature of nutrition, 
 partly for pul)lication in the Experiment Station Record; the conducting of a large 
 correspondence growing out of nutrition investigations, and the distribution of pub- 
 lications on this subject. This w^ork is in charge of Dr. C. F. Langworthy. 
 
 Cooperating with the U. S. Department of the Interior a series of studies of food 
 consumption has been conchicted in the Government Hospital for the Insane at 
 Washington, D. C. The results obtained were interesting and valuable, and are 
 being utilized to make the diet, which was found to be ample and of good quality, 
 conform to theoretical requirements. This cooperative investigation was begun by 
 Dr. A. B. Richardson and was continued by his successor. Dr. W. A. White, the 
 experimental work having been carried on by Mr. H. A. Pratt. 
 
 Mention should also be made here of other inve.stioations which, 
 while not strictl}' a part of the cooperative inquirv, are yet .so closely 
 related to it that they may be included in this summary: 
 
 On behalf of the New York State Commission in Lunacy an extended series of 
 studies of the food consumption of the New York hospitals for the insane was car- 
 ried on under the supervision of Professor Atwater. 
 
 A study of the food consumption at the Elmira Reformatory, in New York State, 
 was also made under the supervision of Professor Atwater. 
 
 A sum of money has been granted by the Carnegie Institute to Professor Atwater 
 for the development of accessory apparatus and methods for determination of oxygen 
 in connection with the experiments in the respiration calorimeter, and for investiga- 
 tions of the income and outgo of oxygen in the animal organism. The apparatus has 
 been completed and found to be very accurate (see p. 16). 
 
 SOME RESULTS OF NUTRITION INVESTIGATIONS. 
 
 Among the more important results obtained in these investiofations 
 are tho.se from studies of the composition of food material, from 
 dietary studies, digestion experiments, and investigations with the 
 respiratioji calormieter. 
 
 COMPOSITION OF FOOD MATERIALS. 
 
 One result of the investigations of food and nutrition in the United 
 States, including botii the work done as a part of the cooperative 
 incjuiiy and that carried on in other connections, is that we have now 
 a tolerably clear idea of the composition and nutritive values of our 
 ordinal V American food materials. In the latest revised edition of a 
 
U. S. Dept. of Agr., Office of Expt. Stationb, 713. 
 
 Plate II. 
 
 PiilcsZible nutrients 
 
 n_ _j „ J. Car-bo- MinerctV 
 
 i^aicin Fats byoU-octct 7na.Ue.rs 
 
 Indiy^-iAtibU nutncnti Non mitnents. 
 Water Kefu.se. 
 
 Composition of Food Materials. Nutritive Ingredients, Refuse, and Fuel 
 
 Value. 
 
U. S, Dept. cf Agr., Office of Expt- Stations, 713. 
 
 Pla-e mi. 
 
18 
 
 bulletin" puhlishcd in 1903. in wliich these results are compiled, the 
 total number of analyses included was 4,063. Of these, 1,618 were of 
 animal foods, 2,375 of veg-etable foods, and TO of unclassified foods. 
 
 At the present time the number of analyses thus compiled is more 
 than 4,5(H) and is still rapidly increasing-. The}' are now derived 
 more largely from other sources than the cooperative nutrition investi- 
 gations, because in connection with the latter they are made onh' when 
 necessar}', as in digestion and metabolism experiments. They are no 
 longer made simplj' to increase the amount of such data available. 
 Plate II shows in graphic form the composition and fuel value of some 
 of the more common food materials. 
 
 DIETARY STUDIES. 
 
 The number of studies of the actual food consumption of people of 
 dirt'erent classes that have formed part of the cooperative inquiry in 
 ditferent parts of the United States is now over 500. These include 
 studies of families of day laborers, farmers, mechanics, and men in 
 professional life; of peoj^le in congested districts of the slums of New 
 York and Chicago, and poor families in other cities; of negroes in the 
 South; of Spaniards in the extreme Southwest; and of Chinese and 
 fruitarians on the Pacific coast. In a large number of these studies 
 actual analyses were made of food materials and of waste. In addition 
 to the above, which were made entirely as a part of the cooperative 
 nutrition investigations, nearly half as many studies of a similar 
 nature not directly related to the cooperative inquiry have also l^een 
 completed. The latter include studies in private families, in boarding- 
 houses and clubs of men and women in colleges, in hospitals for the 
 insane, and in other institutions. The total number of pei'sons — men, 
 women, and children — included in all these studies is iK)t far from 
 15,000. 
 
 Results of some of the more important dietary studies thus far made 
 are sunnuarized in the following table. These are typical of the 
 studies already published. The data of a consideralile iuunl>er of 
 other studies are now being prepared for publication. 
 
 «U. S. Dept. Agr., Office of Experiment Stations Bui. 28: The Chemical Composi- 
 tion of American Food Materials. Revised edition, 1903. 
 
14 
 
 Summarized results of dktanj studies in the United States 
 [Quantities per man per day.] 
 
 PERSONS WITH ACTIVE WORK. 
 
 Rowing clubs in New England 
 
 Bicyclists in New York 
 
 Football teams in Connecticut and Cali- 
 fornia 
 
 PERSONS WITH ORDINARY WORK. 
 
 Farmers' families 
 
 Mechanics' families 
 
 La) hirers' families in large cities 
 
 Lahiirers' families in more comfortable 
 circumstances 
 
 PROFESSIONAL MEN. 
 
 Lawyers, teachers, etc. 
 College clubs 
 
 MEN WITH LITTLE OR NO EXERCISE. 
 
 Men in respiration calorimeter 
 
 PERSONS IN DESTITUTE CIRCCMSTANCES. 
 
 Poor families in New York City 
 
 Laborers' families in Pittsburg", Pa. 
 
 MISCELLANEOUS. 
 
 Negro families in Alal>ama 
 
 Negro families in Virginia 
 
 Italian families in ('hicago 
 
 French Canadians in Cliicago 
 
 Bohemian families in Cliicago 
 
 Inhiibitantsdf .lava Village, C'olumbian 
 
 E:xi)osition, 1893 
 
 Russian .lews in Chicago 
 
 Mexican families in New Mexico 
 
 Chinese dentist in ('alifornia 
 
 Cliinesc lanndrymeii in California 
 
 Chinese farm lal)orers in California 
 
 Fruitarians 
 
 lUr.TAr.Y STANDARDS. 
 
 Man with very hard muscular work 
 
 f Atwater) . . .' 
 
 Man with hard niuscularwork (Atwater) 
 Man wiih niodiTately active muscular 
 
 work (Atwater) ...". 
 
 Man with light to moderate muscular 
 
 work (Atwater) 
 
 Man at "seileiitary " or woman with 
 
 moderately active work {.\twater) 
 
 Woman at light to uKjderate muscular 
 
 work (Atwater) 
 
 Actually eaten. 
 
 Digestible. 
 
 Gms. 
 1.55 
 186 
 
 97 
 103 
 101 
 
 104 
 
 107 
 
 62 
 109 
 103 
 lis 
 
 ll.T 
 
 66 
 137 
 
 94 
 115 
 135 
 144 
 
 .50 
 
 175 
 150 
 
 125 
 
 112 
 
 100 
 
 90 
 
 Gms. 
 177 
 186 
 
 354 
 
 130 
 150 
 116 
 
 125 
 148 
 
 132 
 1.59 
 111 
 
 1.58 
 101 
 
 19 
 103 
 
 71 
 113 
 
 76 
 
 95 
 102 
 
 («) 
 (") 
 
 («) 
 
 (") 
 
 C) 
 
 1 
 
 Si 
 
 O 
 
 d 
 'S 
 
 Gms. 
 
 Gms. i 
 
 440 
 
 143 
 
 651 
 
 171 
 
 634 
 
 208 
 
 467 
 
 89 
 
 402 
 
 95 
 
 344 
 
 93 
 
 534 
 
 110 i 
 
 423 
 
 96 
 
 459 
 
 98 
 
 305 
 
 103 
 
 407 
 
 86 
 
 308 
 
 74 
 
 436 
 
 57 
 
 444 
 
 100 
 
 391 
 
 95 
 
 345 
 
 109 
 
 360 
 
 106 
 
 254 
 
 61 
 
 418 
 
 126 
 
 613 
 
 86 
 
 289 
 
 106 
 
 566 
 
 124 
 
 ■ 640 
 
 132 
 
 237 
 
 43 
 
 {«) 
 
 161 
 
 («) 
 
 138 
 
 (") 
 
 115 
 
 («) 
 
 103 ; 
 
 (") 
 
 92 
 
 («) 
 
 83 
 
 168 
 177 
 
 336 
 
 124 
 143 
 110 
 
 119 
 141 
 
 125 
 151 
 105 
 150 
 96 
 
 18 
 98 
 67 
 107 
 72 
 90 
 92 
 
 (") 
 (") 
 («) 
 («) 
 («) 
 
 Gins. I Cals. 
 427 ' 3,955 
 631 5, 005 
 
 453 3,415 
 390 I 3,355 
 334 2,810 
 
 518 3, 925 
 
 410 3, 220 
 445 3,580 
 
 296 2, 380 
 
 395 
 299 
 
 423 
 342 
 379 
 335 
 349 
 
 246 
 405 
 595 
 281 
 549 
 621 
 
 («) 
 (") 
 («) 
 («) 
 
 2, 845 
 2,400 
 
 3,165 
 3, 625 
 2, 965 
 3. 260 
 
 2,800 
 
 1,4.50 
 3, 135 
 3, 460 
 2, 620 
 3, 480 
 3,980 
 2, 055 
 
 5, .500 
 4,1.50 
 
 3,400 
 
 3, 050 
 
 2, 700 
 
 2, 4.50 
 
 6.6 
 
 6 
 
 8.2 
 7.5 
 6.3 
 
 4.5 
 
 6.9 
 6.8 
 
 12.4 
 6.8 
 6.5 
 6. 2 
 5.3 
 
 4.7 
 5 
 
 8.7 
 4.9 
 5.7 
 6.2 
 10 
 
 7.2 
 6.2 
 
 0.2 
 
 6.1 
 
 6.1 
 
 6.1 
 
 " Fats ai;<l carbohydrates in sufficient amounts to furnish, together with the protein, the indicated 
 amuuiit of eiiergv. 
 
 The tio'ure.s in the above tabk^ sliow l)oth the total nutrients in the 
 food con.suiiied, as cak-ulated from the weij^'iit.s aiul cheinieal composi- 
 tion, and the dig-e.stil)le nutrients as estimated by use of coefficients of 
 digestil)ility l>a.sed upon the results of diovstion experiments. The 
 
15 
 
 fuel value of the diet — i. c, the amount of energy actually available to 
 the body — has been calculated by the use of the most recent factors 
 for fuel value of nutrients. The table also shows dietary standards 
 that have been proposed on the basis of the data obtained in dietary 
 studies, digestion experiments, and investigations with the respiration 
 calorimeter. 
 
 From the results of these investigations it is apparent that varia- 
 tions in diet are in part such as naturally follow differences in the actual 
 food supply; but the}' are also intluenced to some extent by race habits, 
 and to a still larger extent by the amount of muscular work performed 
 and by the material circumstances of the consumer, including espe- 
 cially his income. 
 
 One of the most important ways in which practical application may 
 be made of the results of these studies to the benetit of large numbers 
 of people is in teaching the relative nutritive value of difl'erent food 
 materials and their pecuniar}^ economy. Much is already being done 
 in this direction in different parts of the United States. 
 
 The proper nourishment of the inmates of institutions where large 
 num))ers must be fed, such as schools, reformatories, prisons, and hos- 
 pitals, is a subject that is attracting no little attention at the present 
 time. In many instances dietary studies have been made in schools, 
 college clubs, etc., and the information obtained has been of much use. 
 That such studies have been found to have a practical value, and that 
 the interest in them is widespread, is shown by the fact that a consid- 
 erable number have been undertaken by instructors and others inter- 
 ested, aside from those carried on by the Department of Agriculture. 
 The dietar}" studies were made under widely varying conditions. Plate 
 III, showing Chinese farm laborers at dinner, is an illustration of this. 
 These laborers were one of the groups studied in an investigation of 
 the dietary of Chinese on the Pacific coast. 
 
 As a result of such studies as those described above, the dietary 
 standards included in the table have been suggested. These are 
 intended to show the actual food requirements of persons under dif- 
 ferent conditions of life and work, and how these requirements may 
 be most economically and efficiently supplied by the available food 
 materials. It is not claimed, however, that the food each da}- should 
 contain exactly the kind and amounts of the different nutrients 
 required by the standards. A slight deficiency one da}^ will be made 
 good l)y an excess the next, the body serving as a storehouse for 
 reserve material. Experience has, however, shown that the bodj' is 
 best nourished when through long periods the food approximates the 
 requirements of the so-called standards. Individual requirements and 
 individual peculiarities will always affect the choice of foods.. 
 
 The exact knowledge which comes with such researches is showing 
 how the diet of largo classes of our population ma}' be materially 
 improved while often its cost may be considerably reduced. 
 
16 
 
 DIGESTION EXPERIMENTS. 
 
 Nearly 600 digestion experiments, mosth^ with men but a few with 
 women and children, have been made in connection with the nutrition 
 investigations of the Department. In connection with nearly half of 
 these the income and outgo of nitrogen has been determined, thus 
 making them nitrogen metabolism experiments also. 
 
 The results of these digestion experiments show the digestibili't}- of 
 various sorts of mixed diet and of individual food materials. Taking 
 these results into account, together with the results of analyses, we 
 are able to prepare tables showing the average quantities of digestible 
 nutrients in a large numl)er of the food materials in most common use. 
 
 METABOLISM EXPERIMENTS WITH THE RESPIRATION CALO- 
 RIMETER. 
 
 From the more purelv scientific standpoint, the interest of this 
 cooperative nutrition inquiry culminates in the experiments with the 
 respiration calorimeter. These have for their object the stud}' of the 
 transformation of matter and energy in the living organism. In other 
 words, they represent an inquiry into the most fundamental and most 
 important laws of nutrition. The apparatus used for the purpose, 
 known as the Atwater-Rosa respiration calorimeter, wdiich has been 
 developed in connection with these investigations, suffices for the 
 accurate measurement of the income and outgo of all chemical elements 
 except oxygen, of the potential energy of food, of unoxidized excre- 
 tory products, of body material gained or lost, and of the kinetic 
 energy given otf from the body in the forms of heat and external 
 muscular work. Accessory apparatus and a method for the direct 
 determination of income and outgo of oxygen have very recenth' been 
 completed by Professors Atwater and Benedict, and it is possible with 
 the calorimeter as thus modified to determine directly all the elements 
 of income and outgo and in addition to study the respiratory quotient 
 which is known to be a very delicate index of the processes going on 
 in the body. Plate IV gives ageneral view of the respiration calorim- 
 eter, and Plate V a ground plan of the cidorinieter laboratory. 
 
 One very important result thus far obtained by the use of this 
 apparatus is what amounts practically to a demonstration that the 
 law of the conservation of energy applies to the living organism. 
 The proof that this law obtains in the inorganic world was one 
 of the great scientific achievements of the last century. It has, of 
 course, been assumed and very generally believed that it nmst also 
 apply in the organic world — in the living being; but a complete 
 and satisfactory demonstration has not hitherto been made, although 
 an approximate proof was found in a iuim})er of European exp(>ri- 
 ments with dogs. As the outcome of 04 experiments by Professors 
 
U. S. Dept. of Agr., Of ice of Expt. Stations, 713. 
 
 Plate IV. 
 
U. S. Dept. of Agr., Office of Expt. Stations, 713. 
 
 Plate V. 
 
 ^\^ 
 
 
 
 
 1^ 
 
 nH 
 
 O 
 
 -< 
 z. 
 
 
 
 < 
 z 
 
 
 
 
17 
 
 Atwater and Benedict, and their associates, at Wesleyan University, 
 made with (> different men, covering- an aggregate of one hundred and 
 eighty-four days, the ratio of the potential energy of the material 
 oxidized in the bod}- to the energy given otf from the body in the 
 forms of heat and muscular work, as measured by the respiration 
 calorimeter, is as 1,000 to 99!>. The same ratio of 1,000 to 999 was 
 found in the average of a large number of experiments made to test 
 the accuracy of the apparatus. Closer agreement than this could not 
 be looked for. 
 
 The practical usefulness of this apparatus and method of inquiry 
 will be realized more clearly when we consider that it gives us a means 
 for measuring more exactl}' than has hitherto been possible, the trans- 
 formations of matter and energy which take place in the bodies of 
 different persons with different kinds and amounts of food or in fast- 
 ing, and under widely varying conditions of muscular and mental 
 activity. The experiments furnish a mass of data needed for various 
 sciences of physiolog}^ and hygiene. These data have to do with 
 food, drink, and excretory products and with the metabolic processes 
 and changes of bod}^ tissue as they are influenced by work, sleep, 
 diet, temperature, and other circumstances. They show the nutritive 
 values of food and the demands of the body in health and disease. 
 Incidentally the}^ throw valuable light on problems of ventilation and 
 numerous other questions of hygiene. They supply the foundations 
 of the doctrine of nutrition and belong to the highest order of scien- 
 tific research. 
 
 FACTORS FOR DIGESTIBILITY AND FUEL VALUE OF NUTRIENTS. 
 
 The data obtained in the nutrition investigations ma}' be used in 
 deducing certain factors which are useful in various ways to students 
 and investigators of similar problems, and to some extent also to those 
 who wish to make practical application of the results. Such factors, 
 for the digestibility and fuel value of the nutrients of ordinar}- mixed 
 diet have been epitomized b}' Professor Atwater in the following 
 table: 
 
 31^823— IM- — 2 
 
Factors for digestibility and fuel value of nutrients in mixed diet. 
 
 
 Protein. 
 
 Fat. 
 
 Carbohydrate 
 
 
 i- 
 
 
 5 ^ 
 
 1 
 
 5 
 
 Fuel value 
 per gram. 
 
 5 " 
 
 Si 
 
 1 
 
 5 
 
 Fuel value 
 per gram. 
 
 pi 
 
 3 
 
 a 
 be 
 
 s 
 
 Fuel value 
 per gram. 
 
 
 materials. 
 
 
 5S 
 
 
 II 
 
 5 £ 
 
 il 
 
 Eh 
 
 11 
 
 .£fa 
 
 1 ^^ 
 
 C ^ ^ 
 
 Meal nnd fish 
 
 Pa- 
 cent. 
 43 
 
 6 
 
 Per 
 
 cent. 
 
 97 
 
 97 
 
 97 
 
 Calor- 
 ics. 
 4.27 
 4.37 
 
 Calor- 
 ics. 
 4.40 
 4.50 
 
 Per 
 cent. 
 
 \ 60 
 
 32 
 
 Per 
 
 cent. 
 95 
 95 
 
 Cator- 
 
 9.03 
 
 8.79 
 
 ffS. 
 
 9.50 
 9.25 
 
 Per 
 cent. 
 
 Per 
 cent. 
 
 98 
 
 Calor- 
 ies. 
 
 3.82 
 
 Cator- P?)- 
 •es. 1 cent. 
 
 1 87 
 3.90 ' S9 
 
 Dairy products 
 
 V> 
 
 4.27 j 4.40 
 
 ■ 1 93 
 
 Animal food 
 (of mixed 
 diet) 
 
 61 
 
 97 
 
 4.27 
 
 4.40 
 
 92 
 
 95 
 
 8.93 
 
 9.40 
 
 5 
 
 98 
 
 3.82 
 
 3. 90 89 
 
 Cereals 
 
 31 
 
 85 
 
 78 
 
 3.87 
 3.47 
 
 4.55 
 4.45 
 
 r ^ 
 
 90 
 
 8.37 
 
 9.30 
 
 55 
 
 1 
 
 1 21 
 
 "is' 
 
 I 5 
 
 98 
 97 
 98 
 98 
 95 
 90 
 
 4.11 
 4.07 
 3.87 
 4.11 
 3.99 
 3.60 
 
 4.20 ! 91 
 
 Legumes (dried) ... 
 
 2 
 
 4.20 
 3.95 
 4.20 
 4.20 
 4 00 
 
 83 
 98 
 
 
 
 98 
 
 
 5 
 1 
 
 83 
 85 
 
 3.11 
 3. 36 
 
 3.75 
 
 
 91 
 
 Fruit 
 
 3.95 J 
 
 «.s 
 
 
 
 
 Vegetable 
 food (of 
 mixeddiet). 
 
 39 
 
 So 
 
 3.74 
 
 4.40 
 
 8 
 
 90 
 
 8.37 
 
 9.30 
 
 95 
 
 97 
 
 4.03 
 
 4.15 
 
 92 
 
 Total food (of 
 mixeddiet). 
 
 100 
 
 92 
 
 4.05 
 
 4. 40 100 
 
 95 
 
 8.93 
 
 9.40 
 
 100 
 
 97 
 
 4.03 
 
 4.15 
 
 91 
 
 Briefly stated, on an average about 96 per cent of the total organic 
 matter of mixed diet will l)e digested and !)1 per cent of the energy will 
 be available to the bod}- or, in other words, the body rejects about 4 
 per cent of the nutrients and al)out 9 per cent of the energy supplied 
 by the food. 
 
 With the exception of .some important European determinations of 
 heats of combustion, the figures given in the above talde are derived 
 from late investigations in the United States. These included over 
 4,500 analyses of food materials; over 500 dietary .studies; nearly (iOO 
 digestion experiments, mostly with men; several thousand determina- 
 tionsof heatof combustion of food materials and excretor}" products, and 
 CA experiments, covering in the aggregate 184 days, with men in the 
 respiration calorimeter, besides a considerable number of other experi- 
 mental iiKjiiirics, including especially the determinations of the con- 
 stitution of protein compounds in various materials. The results of 
 comi)utati()ns by means of these factoivs have been found to agree very 
 closely with those obtained in actual experiments, showing that the 
 factors are reasonablv accunite. 
 
 THE PECUNIARY ECONOMY OF FOOD. 
 
 The sum expended for food is the princii)al item in the living 
 expenses of a large majority of families, and Net very few of e\en the 
 most intelligent housekeepers have clear ideas regarding the actual 
 nutritive Nalue of difl'erent food materials. Very generally, even those 
 who endeavor to economize know little of the combinations which are 
 best fitted for nourishment and have still less information as to the 
 
U. S. Dept. of Agr., Office of Expt. Stations, 71; 
 
 Plate VI. 
 
 protein. 
 
 Fhts 
 
 Carbohydrates 
 
 Fuel Value. 
 
 FOOD MATERIALS 
 
 Prue 
 
 pound 
 
 ec^ 
 
 7V« 
 
 rents 
 will 
 
 Xv/€> 
 
 Pounds o{nu,Lritnts aruL talones of^ fuft value in. 10 cenb 
 worth. 
 
 lib 
 
 zlbs 
 
 ilbs 
 
 7000 (hi 
 
 foooCai 
 
 6000 Cat/ 
 
 Jlcey, lOAMvd 
 
 i\ , SA.ltOA, 
 
 %ic^ , -a*3ou£cW 
 
 &(i\AJOCav\/, Zi. 
 
 .67> 
 
 <&zXi,X.o 
 
 <z),czM, /aa£t, -|«^ 
 
 e'Ca 1 
 
 ^c d)^.\/s\g , £ii/ff^ ,dxcnp,u> 
 
 I CO 
 
 taclftefe , /TAVwic' 
 
 I.YJ 
 
 &v^iXO, ^$ /ta^x-xymvtt' 
 
 .bi I 
 
 a>1l\C& , ^/i(A\Xs ^utvtt' 
 
 'i'-Vcittl 
 
 MO 
 
 tn: 
 
 m 
 
 v^f-'vii:-?! 
 
 \2c\AS , 2t ccivla' .c>a:;cu 
 
 ■VSiliatAc.^5 
 
 VSHp^jik/^^c-v^-^. 
 
 1?,. f7 
 
 koo 
 
 (S<vk 'nx.caX. 
 
 : ,^0 
 
 u: 
 
 (Kean'E>, -vefetti . c!tiCi? 
 
 »3a\ 
 
 e'j la loes , SCcent? MtM^hii 
 
 Q>v 
 
 \&Z 
 
 Pecuniary Economy of Food. Amounts of Actually Nutritive Ingredients 
 Obtained in Different Food Materials for 10 Cents. 
 
 Amounts of nutrients in pound.s; fuel value in ealories. 
 
19 
 
 relation between the true nutritive value of foods and tlieir cost. Of 
 the different food materials which are palatable, nutritious, and other- 
 wise suited for nourishment, the consumer wishes to know what ones 
 are pecuniarily the most economical; in other words, which foods fur- 
 nish the largest amounts of available nutrients at the lowest cost. In 
 answering" this question it is necessary to take into account not only 
 the prices per pound, quart, or bushel of the different materials, but 
 also the kinds and amounts of the actual nutrients they contain and 
 their titness to meet the demands of the l)ody for nourishment. The 
 cheapest food is that which supplies the most nutriment for the least 
 mone}'. The most economical food is that which is cheapest and at the 
 same time best adapted to the needs of the user. 
 
 In nran}" of the nutrition investigations, especially- the dietary stud- 
 ies carried on by this Department, the cost of food in relation to the 
 nutrients furnished has been considered. Plate VI, which compares 
 a number of common foods from a pecuniary standpoint, shows the 
 amounts of the protein, fat, carbohydrates, and energy which 10 cents 
 worth of each of the food materials selected will supply. In every 
 case the assmiied price per pound is an average value based upon a 
 considerable amount of data collected in different localities. 
 
 THE EDUCATIONAL INFLUENCE OF THE NUTRITION INVESTIGA- 
 TIONS. 
 
 If the piactical usefulness of these investigations is important, the 
 educational influence is no less so. This is manifesting itself in a num- 
 l)er of wa3's, but most of all in bringing the results of the inquirj' 
 directly into schools. Taking all the public schools and the colleges 
 in the country together, the number in which the results of these 
 inquiries are being directly taught is relatively small. Nevertheless, 
 the actual number of institutions in which teachers are including more 
 or less of these results in their courses of instruction, especially in phys- 
 iology, is numericall}" large and is growing with the most encouraging- 
 rapidity. It has been the policy of the Department to deal very gen- 
 erously with schools and with teachers in the distribution of nutrition 
 publications. Not only in cities, but in rural districts, there is a large 
 and rapidl}' growing demand from the schools for these publications. 
 The}' appear to meet an actual want — one that has been rather dimly 
 felt hitherto, but is now becoming much more detinite. The most active 
 call, as would naturally be expected, has been from teachers connected 
 with technical schools or the technical departments of colleges and 
 high schools. The demand, however, has been almost as great from 
 schools of medicine. 
 
 That the time for the development of these inquiries is especially 
 opportune is shown by the use made of the results in the teaching of 
 what is called domestic economy, or household economics. This rep- 
 resents an educational movement of greater import than many I'ealize. 
 
20 
 
 The movement is coming- in response to popular demand and lias the 
 earnest support of many of our leading educators, not a few of whom 
 are emphatic in the expression of their belief in the wisdom of the 
 popular demand and the possibility of making such instruction very 
 useful, especially in courses for girls and young women. Educational 
 experience shows that a certain time is required to bring an}' new 
 subject lirst into scientific and then into pedagogic form. The science 
 of food and nutrition has already assumed reasonal)ly clear and accu- 
 rate scientilic form and is being rapidly brought into pedagogic form. 
 
 CONCLUSION. 
 
 One most important feature of these investigations is the coopera- 
 tion with scientilic. educational, and philanthropic institutions in so 
 many parts of the countr}'. Among the advantages of this method of 
 cooperation several are especially worthy of mention. First, there is 
 the larger econom}" and effectiveness of scientific eti'orts shown in the 
 development of special methods of investigation, in the planning of 
 general and special lines of inquiry, and in the comparison and publi- 
 cation of results. The cooperating investigators and institutions are 
 contributors to the enterprise, and the spirit of cooperation thus 
 becomes in itself an important agency for diffusing the results and 
 insuring their most useful application. Another advantage is found 
 in the fact that, while institutions and investigators have that liberty 
 of initiative and action which is so essential for scientilic research, tlie 
 several inquiries are so coordinated, and investigators are so aided by 
 counsel and b}' the collating of the results of inquiry elsewhere as to 
 give both the individual investigations and the research as a whole 
 far more influence and usefulness than would otherwise be possible. 
 From the practical standpoint also there is an advantage in the fact 
 that so many different institutions, representing the varied interests 
 of people in widely separate regions, are united in the study of preva- 
 lent conditions and in efforts toward improvement. Besides this the 
 funds provided b}' the Department are used economical!}' and are 
 supplemented by the resources of the institutions and often l)v means 
 from other sources. Thus not only is a large amount of Avork being- 
 done, but the interest is widel}^ extended and the results are given 
 very great practical usefulness. 
 
 So it has come about that from modest beginnings, in which work 
 was carried on largely with the aid of private individuals, these inves- 
 tigations under the auspices of this Department have assumed a mag- 
 nitude quite out of proportion to their actual cost; have achieved a 
 noteworthy significance in scientific, educational, sociological, and 
 economic results; and by the extensive coo})eration of individuals and 
 institutions of various kinds with this Department a large amount of 
 valuable work is being done in a systematic way, the results of which 
 are made available to the i)ublic. 
 
 O 
 
LIST OF PUBLICATIONS OF THE OFFICE OF EXPERIMENT STATIONS ON 
 THE FOOD AND NUTRITION OF MAN-Continued. 
 
 Bui. 89. Experiments oil the Effect of Muscular Work upon the Digestibility of Food and the Metab- 
 olism of Nitrogen. Conducted at the University of Tennessee, 1897-1899. By C. E. Wait. 
 Pp. 77. Price, 5 cents. 
 
 Bui. 91. Nutrition Investigations at the University of Illinois, North Dakota Agricultural College, 
 and Lake Erie College, Ohio, 189G-1900. By H. S. Grindley ant} J. L. Sammis, E. F. Ladd, 
 anil Isabel Be vier and Elizabeth C. Sprague. Pp. 4i2. Price, 5 cents. 
 
 Bui. 98. The Eft'ect of Severe and Prolonged ;Museular Work on Food Consumption, Digestion, and 
 Metabolism, by W. O. Atwater and H. C. Sherman, and the Mechanical Work and Efficiency 
 of Bicyclers, by R. C. Carpenter. Pp. G7. Price, 5 cents. 
 
 Bui. 101. Studies on Bread and Bread Making at the University of Minnesota in 1899 and 1900, By 
 Harry Snyder. Pp. f>5. Price, 5 cents. 
 
 Bui. 102. Experiments on Losses in Cooking Meat, 1898-1900. By H. S. Grindley, with the coopera- 
 tion of H. M(tCormack and H. C. Porter. Pp. 64. Price, 5 cents. 
 
 Bui. 107. Nutrition Investigations among Fruitarians and Chinese at the California Agricultural 
 Experiment Station, 1899-1901. Bv M. E. Jaffa. Pp.43. Price, 5 cents. 
 
 Bui. 109. Experiments on the ^Metabolism of Matter and Energy in the Human Body, 1898-1900. By 
 W. O. Atwater and F. G. Benedict, with the cooperation of A. P. Brvant, A. W. Smith, and 
 J. F. Snell. Pp. 147. Price, 10 cents. 
 
 Bui. 116. Dietary Studies in New York City in 1896 and 1897. By W. O. Atwater and A. P. Bryant. 
 Pp. 83. Price, 5 cents. 
 
 Bui. 117. Experiments on the Effect of Muscular Work upon the Digestibility of Food and the Metab- 
 olism of Nitrogen. Conducted at the University of Tennessee, 1899-1900. By C. E. Wait. 
 Pp. 43. Price, 5 cents. 
 
 Bui. 121. Experiments on the Metabolism of Nitrogen, Sulphvir, and Phosphorus in the Human 
 Organism. By H. C. Sherman. Pp.47. Price, 6 cents. 
 
 Bui. 126. Studies on the Digestibilitv and Nutritive Value of Bread at the University of Minnesota in 
 1900-1902. By Harry Snyder. Pp. .^2. Price, 5 cents. 
 
 Bui. 129. Dietary Studies in Boston and Springfield, Ma.ss., Philadelphia, Pa., and Chicago, 111. By 
 Lydia Southard, Ellen H. Richards, Susannah U.sher, Bertha M. Terrill, and Amelia 
 Shapleigh. Edited by R. D. Milner. Pp. 103. Price, 10 cents. 
 
 Bui. 132. Further Investigations among Fruitarians at the California Agricultural Experttnent 
 Station. By M. E. Jaffa. Pp. 81. Price, ."> cents. 
 
 Bui. 136. Experiments on the Metabolism of Matter and Energy in the Human Body, 1900-1902. By 
 W. O. Atwater and F. A. Benedict, with the cooperation of A. P. Bryant, R. D. Milner, and 
 PiTul Merrill. Pp. ,3.57. Price, 20 cents. 
 
 Bui. 141. Exjieriments on Losses in Cooking Meat, 1900-1903. By H. S. Grindley and Timothy 
 Mojonnier. Pp. 96. Price, 5 cents. 
 
 Bui. 143. Studies on the Digestibility and Nutritive Value of Bread at the Maine Agricultural Experi- 
 ment Station, 1899-1903. By C. D. Woods and L. H. Merrill. Pp. 77. Price, 6 cents. 
 
 farmers' bulletins. 
 
 *Bul. 23. Foods: Nutritive Value and Cost. By W. O. Atwater. Pp. 32. 
 
 Bui. 34. Meats: Composition and Cooking. By C. D. Woods. Pp. 29. 
 
 Bui. 74. Milk as Food. Pp. :39. 
 
 Bui. 85. Fish as Food. Bv C. F. Langworthy. Pp. 30. 
 
 Bui. 93. Sugar as Food. • By Marv H. Abel. Pp. 27. 
 
 Bui. 112. Bread and the Principles of Bread Making. By Helen W. Atwater. Pp. 39. 
 
 Bui. 121. Beans, Peas, and other Legumes as Food. By Mary H. Abel. Pp. 32. 
 
 Bui. 128. Eggs and their Uses as Food. Bv C. F. Langworthv. Pp. 32. 
 
 Bui. 142. Principles of Nutrition and Nutritive Value of Food. Bv W. O. Atwater. Pp. 48. 
 
 Bui. 182. Poultry as Food. By Helen Atwater. Pp. 40. 
 
 CIRCUL.VR. 
 
 Cir. 46. The Functions and Uses of Food. By C. F. Langworthy. Pp.10. 
 
 SEPARATES. 
 
 *Food and Diet. By W. O. Atwater. Reprinted from Yearbook of Department of Agriculture for 
 
 1894. Pp. 44. • 
 
 Some ResuKsof Dietary Studies in the ITnited States. By A. P. Bryant. Reprinted from Y'earbook 
 
 of Department of Agriculture for 1S9S. Pp. 14. 
 Development of the Nutrition Investigations of the Department of Agriculture. By A. C. True and 
 
 R. D. Milner. Reprinted from Yearbook of Department of Agriculture for 1899. Pp. 16. 
 The Value of Potatoes as Food. By C. F. Langworthy. Reprinted from Y'earbook of Department of 
 
 Agricnlmre for 1900. Pp. 16. 
 Dietaries in Public Institutions. By W. 0. Atwater. Reprinted from Yearbook of Department of 
 
 Agriculture for 1891. Pp.18. 
 The Cost of Food as Related to its Nutritive Value. By R. D. Milner. Reprinted from Yearbook of 
 
 Department of Agriculture for 1902. Pp.19. 
 Scope and Results of the Nutrition Investigations of the Office of Experiment Stations. Reprinted 
 
 from Annual Report of the Office of Experiment Stations for the vear ended June 30, 1901. 
 
 Pp. .50. 
 Dietary Studies of Groups, Especially in Public Institutions. By C. F. Langworthy. Reprinted from 
 
 Annual Report of the OJBice of Experiment Stations for the year ended June 30, 1902. 
 
 Pp. 34. 
 
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