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NOTICE: The project that is the subject of this report was approved by the Governing Board of the National Research Council, whose members are drawn from the councils of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. The members of the committee responsible for the report were chosen for their special competencies and with regard for appropriate balance. Part I of this report has been reviewed by a group other than the authors according to procedures approved by a Report Review Committee consisting of members of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine.
The Institute of Medicine was established in 1970 by the National Academy of Sciences to enlist distinguished members of the appropriate professions in the examination of policy matters pertaining to the health of the public. In this, the Institute acts under both the Academy’s 1863 congressional charter responsibility to be an adviser to the federal government and its own initiative in identifying issues of medical care, research, and education. Dr. Kenneth R. Shine is president of the Institute of Medicine.
This report was produced under grants DAMD17-86-G-6036/R and DAMD17-92-J-2003 between the National Academy of Sciences and the U.S. Army Medical Research and Development Command. The views, opinions, and/or findings contained in chapters in Parts II and III that are authored by U.S. Army personnel are those of the authors and should not be construed as official Department of the Army positions, policies, or decisions, unless so designated by other official documentation. Human subjects who participated in studies described in those chapters gave their free and informed voluntary consent. Investigators adhered to U.S. Army regulation 70-25 and United States Army Medical Research and Development Command regulation 70-25 on use of volunteers in research. Citations of commercial organizations and trade names in this report do not constitute an official Department of the Army endorsement or approval of the products or services of these organizations. The chapters are approved for public release; distribution is unlimited.
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COMMITTEE ON MILITARY NUTRITION RESEARCH
ROBERT O. NESHEIM (Chair),
Department of Internal Medicine, Veterans Affairs Medical Center, Hampton, Virginia
WILLIAM R. BEISEL,
Department of Immunology and Infectious Diseases, Johns Hopkins University School of Hygiene and Public Health, Baltimore, Maryland
JOEL A. GRINKER,
Program in Human Nutrition, School of Public Health, University of Michigan, Ann Arbor
Department of Medicine, University of Vermont, College of Medicine, Burlington
Department of Food Science and Human Nutrition, Colorado State University, Fort Collins
Nabisco Brands Incorporated, East Hanover, New Jersey
JOHN A. MILNER,
Department of Nutrition, Pennsylvania State University, State College
JAMES G. PENLAND,
U.S. Department of Agriculture Research Service, Grand Forks Human Nutrition Research Center, Grand Forks, North Dakota
Division of Nutrition, Food and Drug Administration, Washington, D.C.
ALLISON A. YATES,
College of Health and Human Sciences, University of Southern Mississippi, Hattiesburg
Food and Nutrition Board Liaison
JOHANNA T. DWYER,
Frances Stern Nutrition Center, New England Medical Center Hospital, Boston, Massachusetts
Committee on Military Nutrition Research U.S. Army Grant Officer Representative
COL ELDON W. ASKEW,
U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts
BERNADETTE M. MARRIOTT, Program Director
VALERIE McCADDON BREEN, Project Assistant
FOOD AND NUTRITION BOARD
M.R.C. GREENWOOD (Chair),
Office of Graduate Studies, University of California, Davis
EDWIN L. BIERMAN (Vice Chair),
University of Washington School of Medicine, Seattle
PERRY L. ADKISSON,
Department of Entomology, Texas A&M University, College Station
LINDSAY H. ALLEN,
Nutritional Sciences, University of Connecticut, Storrs
DENNIS M. BIER,
Pediatric Endocrinology and Metabolism, Washington University School of Medicine, St. Louis, Missouri
HECTOR F. DeLUCA,
Department of Biochemistry, University of Wisconsin-Madison, Madison
MICHAEL P. DOYLE,
Department of Food Science and Technology, University of Georgia, Griffin
JOHANNA T. DWYER,
Frances Stern Nutrition Center, New England Medical Center Hospital, Boston, Massachusetts
JOHN W. ERDMAN, Jr.,
Department of Food Sciences and Division of Nutritional Sciences, College of Agriculture, University of Illinois, Urbana
Consumer Healthcare Division, Miles Incorporated, Elkhart, Indiana
Division of Nutritional Sciences, Cornell University, Ithaca, New York
K. MICHAEL HAMBIDGE,
Department of Pediatrics, University of Colorado Medical Center, Denver
JANET C. KING,
Department of Nutritional Sciences, University of California, Berkeley
JOHN E. KINSELLA,
School of Agriculture and Environmental Sciences, University of California, Davis
LAURENCE N. KOLONEL,
Cancer Center of Hawaii, University of Hawaii, Honolulu
Graduate School of Biomedical Sciences, University of Texas, San Antonio
School of Hygiene and Public Health, Johns Hopkins University, Baltimore, Maryland
VERNON R. YOUNG,
School of Science, Massachusetts School of Technology, Cambridge
STEVE L. TAYLOR (Ex Officio),
Department of Food Science and Technology, University of Nebraska, Lincoln
ARTHUR H. RUBENSTEIN (IOM Liaison),
Department of Medicine, University of Chicago, Chicago
This publication, Nutritional Needs in Hot Environments, is another in a series of reports based on workshops sponsored by the Committee on Military Nutrition Research (CMNR) of the Food and Nutrition Board (FNB), Institute of Medicine, National Academy of Sciences. Other workshops or mini-symposia have included such topics as body composition and physical performance, nutrition and physical performance, cognitive testing methodology, and fluid replacement and heat stress. These workshops form a part of the response that the CMNR provides to the Assistant Surgeon General of the Army regarding issues brought to the committee through the Military Nutrition Division of the U.S. Army Institute of Environmental Medicine (USARIEM) at Natick, Massachusetts.
FOCUS OF THE REPORT
The timing of the request in the late fall of 1990 from the Nutrition Division of the U.S. Army Institute of Environmental Medicine (USARIEM) to examine the topic of nutritional needs in hot environments was undoubtedly influenced by the initiation of Operation Desert Shield (later Desert Storm) and the deployment of military personnel in the harsh desert environment of the Middle East. The ability of troops to perform under these extreme conditions was naturally a matter of concern to military commanders.
The past 50 years have produced only a limited number of studies focused on the influence of heat on nutrient requirements and work perfor-
mance that can be directly applied to military nutrition issues (see the selected bibliography in Appendix B). Recent military-based research has been concerned with nutrient and caloric requirements for work in cold environments (cf. Edwards et al., 1990a,b; Morgan et al., 1988). In 1990, the CMNR produced the report of a workshop, Fluid Replacement and Heat Stress (Marriott and Rosement, 1991), which presented a general review of fluid intake and replacement and also specifically addressed concerns related to military combat activities in both temperate and warm conditions. This report and the previous work of military researchers at the USARIEM formed the basis for the nutritional advice contained in the pocket guide prepared by USARIEM staff for personnel involved in Operation Desert Storm (Glenn et al., 1990).
The present report builds further on Fluid Replacement and Heat Stress and summarizes the current state of knowledge about the influence of high temperatures on nutrient requirements—other than water—for work in hot environments. It also identifies specific areas for additional study. The report discusses as well some of the important issues in delivering nutrients to military personnel through combat field feeding systems. During Operation Desert Storm, Army food scientists prepared an initial review of hot weather feeding and provided recommendations related to feeding and food management issues (Norman and Gaither, 1991).
HISTORY OF THE COMMITTEE
The Committee on Military Nutrition Research (CMNR) was established in October 1982 following a request by the Assistant Surgeon General of the Army that the Food and Nutrition Board of the National Academy of Sciences set up a committee to advise the U.S. Department of Defense on the need for and conduct of nutrition research and on related issues. The committee's tasks are to identify nutritional factors that may critically influence the physical and mental performance of military personnel under all environmental extremes; to identify deficiencies in the existing data base; to recommend research that would remedy these deficiencies and approaches for studying the relationship of diet to physical and mental performance; and to review and advise on standards for military feeding systems. Within this context the CMNR was asked to focus on nutrient requirements for performance during combat missions rather than requirements for military personnel in garrison. (The latter were judged as not significantly different from those of the civilian population.)
Although the membership of the committee has changed periodically, the disciplines represented have consistently included human nutrition, nutritional biochemistry, performance physiology, food science, and psychology. For issues that require broader expertise than exists within the com-
mittee, the CMNR has convened workshops. These workshops provide additional state-of-the-art scientific information and informed opinion for the consideration of the committee in its evaluation of the issues at hand.
COMMITTEE TASK AND PROCEDURES
In late 1990, personnel from the USARIEM requested that the CMNR examine the current state of knowledge concerning the influence of a hot environment on nutrient requirements of military personnel. The nutritional needs of the thousands of troops deployed to the desert environment of Saudi Arabia and other areas of the Middle East for Operation Desert Storm made this an especially urgent issue. A parallel concern was to ensure that performance would not decline as a result of inadequate nutrition.
The committee was aware of the limited studies conducted on this topic for or by the military since World War II. It decided that the best way to review the state of knowledge in this diverse area was through a small workshop at which knowledgeable researchers could review published research and provide an update on current knowledge. Such a workshop would enable the CMNR to review the adequacy of the current nutrient specifications for military operational rations and to identify gaps in the knowledge base that might be filled by future research.
A subgroup of the committee met in December 1990, determined the key topics for review, identified speakers with expertise in these topics, and planned the workshop for April 1991. Invited speakers were asked to prepare a review paper on their assigned topic for presentation and publication and to identify gaps in the data base. The CMNR also believed that it would be beneficial to obtain actual observations from a military field research team to aid in evaluating the performance of current field feeding systems used in Operation Desert Storm. The stress on logistical systems during the operation did not permit fielding a research group specifically for this purpose; however, the committee identified two speakers who were in the operation theater on other assignments and who presented informal commentary at the workshop on troop feeding during Operation Desert Storm. In addition, four scientists who had conducted a controlled research project at the USARIEM on dietary sodium levels during heat acclimation presented their results.
At the workshop, each speaker gave a formal presentation, which was followed by questions and a brief discussion period. The proceedings were tape-recorded and professionally transcribed. At the end of the presentations, a general discussion of the overall topic was held. The next day, the CMNR met in executive session to review the issues, draw some tentative conclusions, and assign the preparation of draft reviews and summaries of specific topics to individual committee members. Committee members sub-
sequently met in a series of working sessions and worked separately and together using the authored papers and additional reference material to draft the summary and recommendations. The final report was reviewed and approved by the entire group. These working sessions included Andre Bensadoun, Bill Evans, Joel Grinker, Richard Jansen, Gil Levielle, John Milner, and Allison Yates. At the request of the committee chairman, Allison Yates developed a summary paper for the committee to stimulate discussion and raise important questions primarily related to heat, food intake, and appetite. This discussion paper is included in Chapter 15 in Part IV.
The summary and recommendations of the Committee on Military Nutrition Research constitute Part I of this volume, and the papers presented at the workshop make up Parts II and III. Part I has been reviewed anonymously by an outside group with expertise in the topic area and experience in military issues. The authored papers in Parts II, III, and IV have undergone limited editorial change, have not been reviewed by the outside group, and represent the views of the individual authors. Selected questions directed toward the speakers and their responses are provided at the end of each chapter to give an indication of the discussion after each presentation. The invited speakers were also requested to submit a brief list of selected background papers prior to the workshop. These recommended readings, as well as relevant citations obtained through a computerized literature search, and the citations from each chapter are included in the Selected Bibliography (Appendix B).
It is my pleasure as chairman of the CMNR to acknowledge the contributions of the FNB staff, particularly the excellent technical and organizational skills of Bernadette Marriott, Ph.D., the FNB program director for the CMNR. Her assistance in organizing the workshop, and in bringing the proceedings to the point of publication, is greatly appreciated. I wish to acknowledge as well the fine contributions by the workshop speakers and their commitment to participate and prepare detailed review papers on relatively short notice. The CMNR appreciates the assistance of COL E. Wayne Askew and others from the USARIEM for their assistance in identifying issues of concern to the military and obtaining the involvement of the military personnel who participated in the workshop. COL David Schnakenberg's scientific expertise and his historical knowledge of relevant military studies contributed significantly, as in the past, to the success of this workshop. An earlier summary of the history of the Military Recommended Dietary Allowances, prepared by COL Schnakenberg, was invaluable in developing this report. The critiques of the anonymous reviewers and Food and Nutrition Board liaison member, Johanna Dwyer, in addition to comments by
FNB director Catherine Woteki, provided helpful insight in the development of this final document. The editorial efforts of Judy Grumstrup-Scott and Leah Mazade are gratefully acknowledged. The assistance of Valerie Breen, CMNR project assistant, and Connie Rosemont, FNB research assistant, in word processing, editing, and proofreading this report is greatly appreciated.
Finally, I am grateful to the members of the committee who participated significantly in the discussions at the workshop and in the preparation of the summaries of the proceedings. In particular, I want to thank former committee members Andre Bensadoun and Bill Evans who wrote substantive portions of the initial drafts of Chapter 1. The commitment of the members of this committee, who serve without compensation, to provide sound, timely recommendations for consideration by the military, is commendable. I am personally inspired by my work with this group of dedicated professionals.
ROBERT O. NESHEIM, CHAIRMAN
Committee on Military Nutrition Research
Edwards, J.S.A., D.R. Roberts, J. Edinberg, and T.E. Morgan 1990a The Meal, Ready-to-Eat Consumed in a Cold Environment. Report No. T9-90. United States Army Research Institute of Environmental Medicine. Natick, Mass.
Edwards, J.S.A., D.C. Roberts, S.H. Mutter, and R.J. Moore 1990b A Comparison of the Meal, Ready-to-Eat VIII with Supplemental Pack and the Ration, Cold Weather Consumed in an Arctic Environment. Report No. T21-90. United States Army Research Institute of Environmental Medicine. Natick, Mass.
Glenn, J.R., R.E. Burr, R.W. Hubbard, M.Z. Mays, R.J. Moore, B.H. Jones, and G.P. Krueger, eds. 1990 Sustaining Health and Performance in the Desert: A Pocket Guide to Environmental Medicine for Operations in Southwest Asia. Technical Note 91–2. United States Army Research Institute of Environmental Medicine. Natick, Mass.
Marriott, B.M., and C. Rosemont, eds. 1991 Fluid Replacement and Heat Stress: Proceedings of a Workshop. Second printing. Washington, D.C.: National Academy Press.
Morgan, T.E., L.A. Hodgess, D. Schilling, R.W. Hoyt, E.J. Iwanyk, G. McAninch, T.C. Wells, and E.W. Askew 1988 A Comparison of the Meal, Ready-to-Eat, Ration, Cold Weather, and Ration, Lightweight Nutrient Intakes During Moderate Altitude Cold Weather Field Training Operations. Report No. T5-89. United States Army Research Institute of Environmental Medicine. Natick, Mass.
Norman, E.J., and R.M. Gaither 1991 Review of Army Food Related Operations in Hot Desert Environments. Technical Report Natick/TR-91/008. United States Army Natick Research, Development and Engineering Center. Natick, Mass.
Physiological Responses to Exercise in the Heat
Effects of Exercise and Heat on Gastrointestinal Function
Water Requirements During Exercise in the Heat
Energetics and Climate with Emphasis on Heat: A Historical Perspective
The Effect of Exercise and Heat on Vitamin Requirements
Effects of Heat on Appetite
Situational Influences on Food Intake
Responses of Soldiers to 4-gram and 8-gram NaCl Diets During 10 Days of Heat Acclimation
Endocrinological Responses to Dietary Salt Restriction During Heat Acclimation
Subjective Reports of Heat Illness
Food Intake, Appetite, and Work in Hot Environments