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Executive Summary The primary purpose of fitness and body composition standards in the military has always been to select individuals best suited to the physical demands of military service based on the assumption that proper body weight supports good health, physical readiness, and appropriate military appearance. Prior to the Korean Conflict, these standards were used primarily to exclude underweight candidates. Advances in health care and improved nutrition over the past 75 years have resulted in increases in mean height, weight, and fat-free mass of soldiers, and in the U.S. population as a whole. However, increases in food consumption and decreases in daily activity have raised new concerns about the impact of overnutrition and fatness on overall health, physical fitness, and military performance. BACKGROUND AND CHARGE TO THE COMMITTEE Considerable attention has been given to the alarming rise in the incidence of overweight and obesity in the U.S. population. The most recent national data (]999-2000 National Health and Nutrition Examination Survey) show the prevalence of overweight and obesity (defined as a body mass index tBMI] of > 25 for overweight and > 30 for obesity) in adults 20 years of age and older is 64.5 percent overweight and, of these, 30.5 percent are obese. Furthermore, the prevalence of overweight in adolescents (ages 12-19 years) is 15.5 percent. The epidemic of overweight and obesity affects the military services of the United States in several ways. For example, it decreases the pool of individuals eligible for recruitment into military services, and it decreases the retention of new recruits. Almost 80 percent of recruits who exceed the military accession weight-for-height standards at entry leave the military before they complete their first term of enlistment. This in turn increases the cost of recruitment and training. These issues threaten the long-term welfare and readiness of U.S. military forces.

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2 WEIGHT MANA GEMENT - To aid in developing strategies for the prevention and remediation ot overweight in military personnel, the U.S. Army Medical Research and Materiel Command (USAMRMC), through its director of Military Operational Medicine Research Programs, requested the Committee on Military Nutrition Research (C MAR) to review existing data on: optimal components of a weight-manage- ment program; the role of age, gender, and ethnicity in weight management; and current Department of Defense (DOD) activities in weight management in order to provide recommendations for military weight-management programs. In response to this request, the Subcommittee on Military Weight Management was appointed in September 1999. The subcommittee was charged to identify the most effective interventions for weight loss and weight maintenance, particularly those most pertinent to the nonobese overweight individuals (BMI 25.~29.9) found in the military setting, to evaluate the interventions' appropriateness for military application or the need for further research, and to develop a consensus toward a more standard DOD- wide approach to weight management that utilizes state-of-the-art knowledge and practices. Specifically, the military requested guidance on the appropriate degree of standardization of programs across the services, whether specific aids for weight loss (e.g., drugs) should be considered, how dietary changes would impact successful weight loss, and whether resistiveness to weight loss and maintenance are genetically controlled to the extent that individuals with genetic predispositions for obesity should be identified and automatically excluded. METHODS As part of the response to the military request, the subcommittee convened a workshop to bring together a group of experts to share knowledge and experience in managing weight-control programs within the services, to gain relevant knowledge and experience from industry and academia, to examine current interventions and those under development (particularly in the pharma- ceutical industry) for their appropriateness for military application, and to identify needs for further research. In addition, the subcommittee performed an extensive review of the scientific literature for data on optimal components of a weight-management program; the role of age, gender, and ethnicity in weight management; and current DOD activities in this arena. From this review, recommendations were developed on the optimal components of a weight- management program that could be utilized across the services. CURRENT MILITARY WEIGHT STANDARDS AND WEIGHT-MANAGEMENT PROGRAMS There are significant demographic differences between the military popula- tion and the general U.S. population. The general population is almost evenly

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EXECUTIVE SUMMARY split with respect to gender (49.1 percent men and 50.9 percent women), while the military population is approximately 85 percent men and 15 percent women. There are also significant age differences in the two populations. Approximately 31.5 percent of the U.S. population is between the ages of 18 and 40 years, while approximately 80 percent of the military population is in this age range. The military also has a higher percentage of ethnic minorities than the general population, especially among women. The weight-for-height and body-fat standards of the military services were predicated on the need for the highest level of physical performance in adverse environments-, to maintain a high level of readiness at all times, and to present a trim military appearance (e.g., the image that the individual may convey of the military). These standards theoretically take precedence even when individuals demonstrate an ability to perform their assigned tasks in an exceptional manner. Typically, the various branches of the military service have had two sets of weight/fat standards: one set to be met by potential recruits for accession into initial entry training and another equivalent or more stringent set to be retained in the service once admitted. The initial body composition screen consists of a weight-for-height assessment. Historically, maximum allowable weight-for- height tables are used. When only two anthropometric measurements are used to estimate body composition, height and weight have the highest level of association with the percentage of body fat. Height and weight can also be used to compute BMI, a widely accepted index that correlates with percent body fat. A substantial body of evidence shows that BMI is positively associated with both morbidity and mortality. Each of the services screens active duty personnel at least annually or semiannually for fitness and compliance with weight-for-height standards. Typically, the maximum allowable weights-for-height varied across ser- vices for individuals of the same height, age, and gender, and individual service standards were uniformly more stringent than the DOD recommendations. The disparity in maximum BMI between men and women was marked. For example, prior to 2002, the maximum allowable retention weight-for-height for women in any service corresponded to a BMI of 25.1 (Army), for men it corresponded to a BMI of 28.2 (Air Force). The military uses circumference measurements to estimate body composition. Until the early 1990s, each service employed its own set of measurement equations for estimating body composition. More recently, a single equation for use across all the services has been mandated by DOD. In November 2002, DOD reissued its reference document on implementation policy and procedures for physical fitness and weight/body-fat standards. This policy mandates that the weight-for-height tables for all the service branches will be based on BMI, and that no service may have a standard more stringent than a BMI of 25 or more liberal than a BMI of 27.5. In addition, all branches of the service must use a single, validated equation based on abdominal and neck circumference and height for men;

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4 WEIGHT MANAGEMENT and one based on abdominal, neck, and hip circumference and height for women to estimate percent body fat. Body-fat standards for men shall not be more stringent than 18 percent and not more liberal than 26 percent. For women, the fat standards shall not be more stringent than 26 percent and not more liberal than 36 percent. Individuals who exceed these limits must be referred to a weight-management program A review of the weight-loss programs across the military services highlighted significant deficits that could affect success. All of the programs have a strong motivating component that is highly disciplinary in nature, and the penalties for exceeding the body-fat limits are significant. With exception of those in the Air Force program, the majority of participants receive only minimal counseling by a qualified dietitian. The same appears to be true throughout the services in the area of behavior modification. With the exception of the Air Force and some specific sites in the other services, data collection for program evaluation is lacking. FACTORS THAT INFLUENCE BODY WEIGHT Maintaining a healthy body weight is an extremely complex issue. Main- tenance of fitness and appropriate body-fat standards by military personnel is affected by each individual's genetics, developmental history, physiology, age, physical activity level, diet, environment, and social background. Some of these factors are biologically programmed (e.g., physiology, genetic makeup, age). Other factors can be manipulated by the individual (e.g., physical activity level, diet), while still other factors may require institutional, systemic, or environ- mental changes (e.g., worksite and community design, availability of facilities). Genetics Individuals appear to show significant heterogeneity in their body weight and body fatness responses to altered energy balance, dietary components, and changing activity levels, although little is yet known about the specific causes of heterogeneity. There is a group of at least 20 Mendelian syndromes in which obesity is a component; these genetic disorders are rare, however, and family studies do not suggest that the genes responsible for these syndromes are involved in the common forms of human obesity. For more than 99 percent of obese individ- uals, the genetic basis of their obesity is unknown, and genetics may or may not be a causal factor. The strongest evidence for genetic weight-regulating mechanisms is the recent elucidation of single gene defects that are associated with excessive weight gain in animals. Of the five gene products identified to date as being associated with weight regulation, leptin is the best characterized. Genetic defects in leptin have been associated with extreme obesity in humans. Although

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E,YECRJTI HE SUMMARY extensive efforts have been made to identify mutations in the genes identified as obesity-associated in rodents and in humans, only a handful of individuals have been identified with mutations in any of the genes that have produced obesity in rodents. Physiology A number of phenotypic characteristics have been associated with risk of weight gain, notably alterations in nonvolitional components of energy expendi- ture. Energy expenditure can be divided into three main components: resting 'metabolic rate (RMR), the energy expended at rest, under thermoneutral conditions, and in a postabsorptive state; thermic elect of feeding, the incremental increase in energy expenditure after a meal is consumed, associated with absorption and transport of nutrients and the synthesis, storage, and breakdown of protein, fat, and carbohydrate; and the energy expended for physical activity, primarily voluntary movement, but also including the involuntary movements associated with shivering, fidgeting, and postural control. The RMR accounts for 60 to 75 percent of total energy expended in most adults. A number of studies have been performed to evaluate the effect of exercise, particularly resistance training, on RMR. Results have been inconsis- tent, and thus whether exercise training increases RMR remains controversial. Age Many weight-management experts agree that body weight becomes pro- gressively more difficult to maintain with age. Some research has indicated that body weight and associated circumferences increase with advancing age unless food intake is significantly reduced or physical activity is substantially increased. However, health risk associated with BMI remains unchanged in older individuals. Thus, there appears to be little rationale for increasing the upper BMI range consistent with good health as individuals become older. A large number of cross-sectional studies, however, do demonstrate that body fat increases with age. In contrast to body fat, skeletal muscle mass declines with age beginning around the third decade, and losses of skeletal muscle parallel decreases in bone mass. The mechanisms of body composition changes that accompany aging are multifactorial and include physical inactivity, diet, and hormonal alterations. This loss of lean mass and the gain in fat mass occur even with no apparent change in body weight. Since lean mass contributes the larger share of metabolic activity, total energy expenditure decreases pro- portionally with loss of lean mass.

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6 WEIGHT MANAGEMENT Physical Activity The rapid rise in the prevalence of overweight and obesity in the last 20 years likely reflects major environmental shifts in eating habits and exercise, both of which can be controlled. Some of these shins include changes in the food supply, food availability, food composition, palatability, and affordability, as well as numerous technological advances that have removed the need for physical labor or physical movement (e.g., elevators, escalators, riding lawn mowers, remote controls for televisions and stereos). Physical activity represents an important component of volitional energy expenditure. Reductions in physi- cal activity over the past several decades have likely contributed to the evolution of positive energy balance and the weight gain characteristic of all industrialized societies. Exercise, especially in bouts of 30 minutes of activity or more, can promote fat oxidation because the substrate that is preferentially oxidized by muscle tissue switches from carbohydrate to fat. Thus, chronic extended bouts of exercise may, in effect, substitute for expansion of the adipose tissue, allowing the physically active individual to achieve fat balance while maintaining a lower body-fat mass than the sedentary individual. Food Intake A high energy intake (i.e., energy intake in excess of energy expenditure) or an energy intake that is not adjusted downward with age and declining physical activity is associated with the development of overweight or obesity in suscep- tible individuals. In addition to total energy intake, the character of the diet may clay a role in the etiology of obesity, with high-fat diets potentially promoting ~ ~} ~ ~ ~ _ ^4 A A _ _ ~^ ~ A _ =~ _ ~ ~ ~ increased body weight. Social and Environmental Factors Other factors that contribute to overweight both in the military and in civil- ian populations include meal patterns and eating habits, familial and ethnic fac- tors, cultural norms, socioeconomic status, smoking, alcohol consumption, use of certain common drugs such as anti-allergens, and the use of antidepressants, hypoglycemic agents, and certain antihypertensive agents. Members of the mili- tary population with unusually sedentary job responsibilities and a work envi- ronment that promotes a combination of high-pressured, hasty, and thoughtless overeating along with inactivity are likely to be particularly at risk for weight gain. Thus, the social and environmental context of the overweight individual needs to be carefully evaluated.

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E,YECUTI HE SUMMARY 7 RECOMMENDATIONS After careful review of the information presented at the workshop and the scientific literature, the subcommittee makes the following specific recommen- dations. Prevention Each service should provide training on diet and health, including the fundamentals of energy balance, the caloric content of common foods, portion sizes, and the importance of maintaining high levels of daily activity after inten- sive training periods (e.g., initial entry training) to prevent weight gain. An education program on maintaining healthy weight should also in- clude components directed at military spouses and family. Programs to reinforce the concept of exercise and activity as part of the military lifestyle should be developed, along with programs to encourage the reduction of alcohol consumption. Particular emphasis should be placed on providing or upgrading physi- cal fitness facilities and equipment that encourage exercise. The use of rewards for exercise achievement should be reinforced. The services should make the incorporation of"heart-healthy" menus a standard for base dining facilities, with continued emphasis on training all mili- tary cooks in low-fat cooking techniques. Priority consideration should be given to commercial eating establish- ments that routinely offer reasonable portion sizes and low-fat dining options when these establishments are competing for base contracts. Assessment Assessments for weight-for-height and percent body fat should be con- ducted quarterly rather than annually or semi-annually. More frequent assess- ments should be evaluated to determine if they reduce disordered eating and other risky behaviors. . Individuals at risk of increased weight or body-fat gain should be iden- tified at the time of accession (e.g., those entering service over the standard, those with a family history of obesity) and their evaluations monitored so that interventions may be instituted as soon as adverse changes are identified. The incidence of disordered eating behaviors needs to be documented and addressed across all branches of the military.

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8 WEIGHT MANAGEMENT Weight-Loss Programs . A weight-loss diet should be energy deficient by 350 to 1,000 kcal/day; should provide a minimum daily intake of at least 800 kcal/day; should provide a minimum of 60 g of protein/day for women and 75 g of protein/day for men; should provide no more than 30 percent of total energy as calories from fat; and should have a carbohydrate content of no less than 130 g/day (excessively low carbohydrate intake can cause dehydration and impact both physical and cogni- tive function). The daily use of a multivitamin-mineral supplement may be included. . A combination of aerobic and strength training exercise, along with in- creased activities of daily living, is recommended. Energy expended in physical activity should be at a minimum of 2,000 kcal/wk, which amounts to 200 to 300 m~n/wk of moderate-intensity exercise (3.5-5 fur). In keeping with other recent recommendations, 60 min/day of moderate-intensity activity in addition to ac- tivities of daily living is suggested. . Training and support in behavior modification should include stimulus control, relapse prevention, self-monitoring, cognitive restructuring, and men- toring. . Follow-up should include regular contact with weight-management counselors; routine self-monitoring of diet, weight, and physical activity; and ongoing psychological support that could be provided via the Internet or by tele- phone. . . Training programs should be established for all personnel associated with implementing weight-control programs. Training standards for a weight- management military occupational specialty should include training in principles of nutrition, portion control, physical activity/exercise, behavior modification, psychological support, and the use of weight-loss aids. The program should also include mandated continuing education requirements. Research Internet-based programs should be developed using models already in use by the military. Emphasis should be given to the development of a number of options, testing their effectiveness overall, and identifying those with high response rates. Also, the range of individual responses of military personnel should be evaluated since there may be subpopulations that respond well to a given intervention when overall response is not consistent. . An evaluation of military weight-management programs is essential to determine their effectiveness. This evaluation would require following personnel who have completed the program for 2 to 5 years, and perhaps throughout their military career. Recommendations provided in this report are based almost ex-

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EXECUTIVE SUMMARY 9 elusively on data collected in civilian populations, and effectiveness may be quite different in military populations. Many nonprescription preparations are undoubtedly being used in the military for weight loss. Very little is known about their effects on body weight, body composition, overall health, and physical performance. It is particularly important to assess the use of such preparations as well as their effects on mili- tary performance. RESPONSE TO THE MILITARY'S QUESTIONS What are We essential components of art effective weight/fat loss program, and We most effective strategies for sustaining weight loss? Years of research have demonstrated that a program for weight/fat loss can only be effective when it is closely integrated with a program for sustaining weight loss. Essential Components of an Effective Weight/Fat Loss Program . Exercise. For overweight adults who are otherwise healthy, increased physical activity is an essential component of a comprehensive weight-reduction strategy. . Behavior modif cation. The use of behavior and lifestyle modification in weight management is based on a body of evidence that people become or remain overweight as the result of modifiable habits or behaviors and that by changing these behaviors, weight can be lost and weight loss can be maintained. Net dietary energy def cit. Energy expended must exceed energy consumed on a consistent basis over an extended period of time, the length of which depends on the degree of overweight. Education. Information on nutrition principles, food portion control, and the need for energy balance is essential for individuals to develop appropriate eating behaviors. Psychological support and counseling Any weight-management program is likely to be more successful if it is accompanied by structured support mechanisms (e.g., Dom professional counselors, commanders, coworkers, family). Environmental changes. Restructuring the individual's environment to remove factors that promote overeating and underactivity is also a significant part of weight loss and management. The environment includes the home, the workplace, and the community. Structured monitoring. The long-term success of weight management appears to depend on a specific and deliberate follow-up program. This struc- . .

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10 WEIGHT MANAGEMENT tured follow-up should include monitoring body weight with regular weigh-ins at least weekly during the weight-loss phase and monthly during the mainte- nance phase. Sustaining Weight Loss An integrated program that combines the weight-loss procedures described above with weight-maintenance strategies is essential to achieve the best long- term benefits. The use of maintenance strategies with the strong incentive that is provided by the military regulations on weight control should enhance the chances for successful weight maintenance. . Physical activity. An expenditure of at least 2,000 to 3,000 kcal/wk from exercise is essential. . Permanent lifestyle and behavior modifications. Balancing customary daily energy intake with appropriate habitual levels of physical activity is also necessary. This includes portion control, selecting foods lower in fat and calories, and consistently sustaining higher levels of daily physical activity. Self-monitoring. Individuals need to record their body weight a minimum of once weekly. They also need to periodically keep a 3-day food diary (about every 3 months) and a physical activity diary or use an activity monitor (e.g., a pedometer) to help maintain weight loss. Continuous structured support. It is also necessary to have follow-up visits or counseling via phone or the Internet every 2 to 4 weeks for the first 3 months and every 1 to 2 months thereafter, depending on the difficulty in maintaining a stable, healthy weight. How do age and gender influence success in weight-management programs? *could age be considered in we~ght/fat standards and in weight-marlagement programs and interventions? Age Although weight gain with age is a frequent occurrence, it is not inevitable. Increases in weight with age can be avoided if energy intake is adjusted to compensate for decreases in activity and the loss of lean body mass, or if physical activity is increased (including strength or resistance exercises) to maintain lean body mass. For the benefit of long-term health, there should not be age-related increases in weight-for-height standards. Research indicates that percent body fat increases with age even if weight does not change. The current upper limits of DOD standards of 26 percent fat in men and 36 percent fat in women, however, is well within the limits of the

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,YECUTI HE SUMMARY 11 healthy percent body fat range even for those 60 to 79 years of age. While individual services have upper limits of percent body fat that are uniformly more stringent than the DOD maximum, increases in percent body fat with age are appropriate. Gender On average, women have a higher percent body fat than men. Weight gain and lifestyle changes during the childbearing and childrearing years, as well as the hormonal and metabolic changes that accompany pregnancy and menopause, are associated with higher body fat. Thus, the gender-specific fat standards are appropriate. Wl~ic/, *irategies would he most and least effective in a military setting? *Gould military weigl't/fat loss programs involve direct participation inter- ve'?tion, or only monitoring and guidance? Should military programs be more proactive ir' identifying and discouraging ineffective or dangerous weight-loss practices? Is a warring or cautionary zone prior to enrollment in a weigl~t- control program an effective strategy? When should dud time be authorized for participation in inierver~tion strategies for weight/fat loss? The Most and Least Effective Strategies of a Weight/Fat Loss Program in a Military Setting The effective strategies for a weight/fat loss program would be the same re- gardless of whether the setting is military or civilian. However, the implementa- tion of some of these strategies could be facilitated in the military environment, particularly physical fitness, exercise, and behavior modification. The primary difficulty in the military setting would be in providing structured follow-up due to the mobility of the military population. Other diffi- culties include remoteness or isolation of some work locations, the paucity of low-fat food selections in vending machines and dining facilities, the availability and affordability of foods with low energy density (e.g., fruits and vegetables, low-fat or nonfat milk), and high-pressure environments with short meal breaks that may promote inappropriate dietary patterns. Direct Participation Interventions versus Monitoring and Guidance Direct participation interventions have been demonstrated to improve com- pliance, increase the success rate of weight/fat loss, and support an improved level of weight maintenance.

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12 WEIGHT MANAGEMENT Identifying and Discouraging Ineffective or Dangerous Weight-Loss Practices Military weight programs should collect information on weight-loss practices of overweight individuals as a component of their medical evaluation. Military individuals found to be using ineffective or dangerous weight-loss practices such as extensive fasting, purging, He use of diuretics, and Me use of commercially available herbal supplements arid diet pills, should be counseled on the risks of these practices and strongly encouraged to adopt standard weight-loss practices. One method to reduce the incidence of dangerous practices is more Dequent weigh- ins and emphasis on appropriate diet and physical activity patterns at all times as part of a military lifestyle. Is a Warning or Cautionary Zone Prior to Enrollment into a Weight-Control Program an Effective Strategy? The warning zone that is now in effect for the Air Force program (3 months) appears to be an excellent strategy. It gives individuals a chance to manage their overweight/body-fat problem by themselves in a timely manner without assignment to a weight control program, with its accompanying career implications. Authorizing Duty Time for Participation in Intervention Programs for Weight/Fat Loss Any medical examination and tests that are appropriate before being assigned to a program for weight/body-fat loss, as well as counseling and monitoring, should be accomplished during duty time. A weight-loss program should be viewed as treatment for a medical condition and be given comparable priority as treatment for other medical conditions. Since current DOD policy dictates regular exercise as a part of duty time, unit commanders should provide (or require) time for regular exercise to ensure a high level of fitness and readiness. To what extent should weight-control programs/policies be standardized across the services versus tailored to the individual service, installation or unit? Bleat are the advantages and disadvantages of standardization? Is the provision of state-of-the-art techniques and knowledge a rationale for stan- dardization?

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EXECUTI HE SUMMARY 13 Extent of Standardization Across the Services versus Tailored to an Individual Service The specifics of implementation of weight-control programs and policies may need to be tailored for each service due to the different environments in which the programs will be carried out (e.g., aboard ships, on CONUS military bases, or on overseas bases). However, they could be standardized across the services to a significant extent as indicated below. A limited number of military health centers should be identified to provide scientifically validated body composition evaluations. . Standard methodology. New technologies for measuring body compo- sition should be adopted service-wide as they become available, once they are validated for accuracy and ease of use. Appearance standard. A waist circumference standard of no more than 40 inches for men and 35 inches for women should be used as an objective measure for appearance standards as these standards are known to be related to long-term health. Weight-management counselors. Those responsible for weight-control programs should be certified and their training should be standardized. Internet-hased weight-management programs. A standardized program across all services would be more efficient and could be easily accessed by military personnel regardless oftheir duty assignment. . The advantages of standardization of weight-control programs and policies are that all military personnel would have access to equivalent weight-manage- ment assistance and that the incorporation of new technologies for body composition assessment and the adoption of Internet-based services would be facilitated. In addition, the costs of producing education materials (e.g., portion size models, brochures) would be reduced. The disadvantage of standardization is that it might limit innovation within the branches ofthe armed forces. There is no scientific disadvantage. Is the Provision of State-of-the-Art Techniques and Knowledge a Rationale for Standardization? Standardization of weight-control program components would facilitate the incorporation of new technologies and provide a stronger base for program evaluation, which would in turn protect DOD investments in each individual. To date, none of the existing military weight-control programs have been sufficiently evaluated to justify adoption DOD-wide.

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14 WEIGHT MANAGEMENT How can diet be effectively dealt with as a weight-management component in the military setting? Should pharmacological treatment (ar~ore~ciants) be considered for use in flee military? In what cases? What factors bear on this decision? Diet counseling needs to be administered by individuals who are fully trained in weight-management strategies, and it should be supported by appropriate professional personnel. For those military personnel who are on ships or are dependent on mess halls, more healthy, low-fat food choices and sufficient time for meal consumption are imperative. Providing choices of foods (both snack and full-meal foods) that are less energy-dense; increasing the price of foods high in calories, fat, and refined carbohydrates; and subsidizing the price of fresh fruits and low-calorie snacks in vending machines and exchange service facilities should be considered. In any case, nutrition and lifestyle education is paramount and should be provided early in the initial entry training period and reinforced periodically. The development of distance-based educa- tion in nutrition and lifestyle modification may prove useful. Pharmacological treatments should be considered for those who meet the standard criteria for the use of such compounds (i.e., a BMI of 2 30 or > 27 with comorbidities such as hypertension or high cholesterol). These individuals would have to be in military occupational specialties that do not preclude the use of drugs that affect the central nervous system. How should resistiveness to weight/fat control be dealt with? Resistiveness, as defined by the military, is a condition that generally refers to a genotype and/or a phenotype that is obesity-prone. These individuals can lose weight, but they usually have to work harder and may need additional assis- tance in a weight-management program and with structured follow-up. Bleat are flee knowledge gaps in weight-management programs relative to the military? What research is needed? Knowledge gaps concerning weight-management programs relative to the military are extensive. Most published research has been derived from studies on middle-aged men and women or perimenopausal, Caucasian women in clinical settings. These data have limited relevance to the military population where: (1) only about 25 percent of officers and warrant officers and about 6 percent of enlisted personnel are over the age of 40, (2) only 15 percent are women, and (3) approximately 40 percent are minorities. Considerable research is needed in the primary areas of prevention, treatment, and program evaluation. In addition to the research needs highlighted in the recommendations, research should also be conducted on the following topics.

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EXECUTIVE SUMMARY Prevention Early Identif cation of Personnel at Risk 15 To identify those at risk of overweight or obesity, a set of potential risk factors for weight gain (e.g., overweight at the time of accession, family history of obesity, initial performance on the physical training test, a gain of more than 5 percent over initial entry training weight) should be developed. The effective- ness of educating these individuals during initial entry training or whenever they are identified as being at risk of becoming overweight should be evaluated. Early Education of Initial Entry Trainees and Families Initial entry training is a time of learning for individuals new to the military. Just as these individuals learn military tasks (e.g., how to fire a weapon), they could also learn nutritional principles, particularly the importance of energy balance, appropriate portion sizes, and the caloric content of frequently consumed foods. Spouses and other family members could also be included in instruction on nutrition, just as they are in classes on military etiquette. Large- scale, randomized trials with alternate classes of recruits, followed over time, would be useful in determining if such preventive efforts are effective. Exercise (Structured and Unstruct2'red~ All the services should adopt the strategy of promoting physical fitness as a way of life from the first day of initial entry training. Mandating exercise during the duty day regardless of time pressures is one strategy. Scheduling competi- tions that require participation by the entire unit and that require unstructured exercise to attain peak performance could be tested as a method to improve overall fitness and activity. The usefulness of resistance or strength training and the optimum mix of aerobic and strength training for the purpose of weight management needs to be evaluated among military personnel. Reduction of Environmental Factors That Promote Overweight Research is needed that: evaluates the effectiveness of eliminating high- calorie and high-fat snacks in vending machines, or of offering alternatives such as fruit and low-calorie snacks and meal replacements; evaluates the effects of different time allotments for meal consumption; and evaluates the effectiveness of altering the environment to promote physical activity, such as the creation of walking and bike trails on military bases.

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16 Evaluation of Treatment Methods and Programs Evaluation of Local Initiatives for Effectiveness WEIGHT MANAGEMENT Research is needed to identify and evaluate local weight-loss programs, both military and civilian, for effectiveness. A military-wide competition could be established for the most innovative weight-reduction programs, with recog- nition and meaningful rewards for the most successful. Evaluation of Ineffective or Dangerous Weight-Loss Practices Research from the Navy has demonstrated that unhealthy eating and purg- ing behaviors are more prevalent among military personnel compared with the civilian population. Information is needed on the impact of such dangerous or ineffective weight-loss practices on physical and mental performance among military personnel. The prevalence of bulimia, binge eating disorder, and ano- rexia nervosa in military personnel and whether the military lifestyle and stan- dards promotes such behavior needs to be determined. Computerized Follow-Up of Personnel at Risk An independent, computerized database is needed to identify individuals with risk factors for weight gain or overweight as described above, and to maintain routine contact with these individuals to check on their weight or physical fitness status, to identify problems early, and to intervene as needed. Such computerized information should be centrally maintained and used as a source of data for longitudinal studies on the effectiveness of prevention and treatment innovations. This data should not be available to unit commanders to avoid the possibility of discrimination against individuals at risk. Other Areas for Research Information is needed on whether there are differences both in gender re- sponses to the various components of weight-management programs (e.g., do men and women respond differently to diet, physical activity, or behavioral change interventions) and in race/ethnicity responses to various weight- management strategies.