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s Response to the Military's Questions Based on a thorough review of the scientific literature, the material pre- sented at the workshop, and current military data and discussions with workshop speakers and others, the subcommittee provides the following responses to the questions posed by the military. It should be noted, however, that prevention of weight and fat gain throughout an individual's military career would be preferable to even the most comprehensive weight-loss program. QUESTION 1 What are flee essential components of an effective weight/fat loss program, and Me most effective strategies for sustaining weigh! 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. The rate of failure to maintain weight loss for those individuals who have successfully completed weight-loss programs has been disappointingly high. Successful cases clearly demonstrate that permanent major lifestyle changes must be adopted during the weight-loss phase of the program in order to prevent regain of the weight lost. Even in the most successful programs, the ma- jority of patients regain some of their lost weight over time. The greatest likeli- hood of success requires an integrated program, both during and after the weight-loss phase, in which assessment, increased energy expenditure through exercise and other daily activities, energy intake reduction, nutri- tion education, lifestyle change, environmental change, and psychological support are all components. Essential Components of an Effective Weight/Fat Loss Program The first component of an effective weight/fat loss program is an appropri- ate assessment. In most cases, body weight and height measurements should be 113
114 WEIGHT MANAGEMENT taken and the individual's body mass index (BMI) calculated Dom this data. If the BMI is within the acceptable range as defined by Me Department of Defense (DOD), no further measurement is necessary. However, if the height and weight measurements indicate that the individual exceeds the service's standards or that the calculated BMI exceeds the newly adopted DOD maximum of 27.5, then additional anthropometric measures should be taken to assess body-fat content. DOD has extensively validated the circumference equations used to estimate percent body fat, and a single equation for men and one for women has now been mandated across all service branches (DOD, 2002~. Care should be taken to assure that the standard procedures for measuring body circumferences are followed. Proper training and adequate criteria for assessing technician skill in conducting accurate circumference measurements should be standardized across DOD. Considering the seriousness of the consequences of overweight for mili- tary personnel, validation of technician skill and availability of the data demon- strating the reliability and repeatability of a technician's circumference measures is warranted. Once there are clear indications that an individual's body-fat mass exceeds desired standards, a medical evaluation should be conducted to deter- mine if a medical condition exists that might be the underlying cause of body-fat accumulation. In the absence of any apparent medical condition, the individual can enter a weight-reduction program. The essential components of a weight/fat loss program include: . Exercise. For overweight adults who are otherwise healthy, increased physical activity is an essential component of a comprehensive weight-reduction strategy. There is compelling evidence that habitual physical activity is associ- ated not only with weight/fat loss, but also with desirable health outcomes (Angotti and Levine, 1994; IOM, 2002; Kesaniemi et al., 2001), and there is evidence from industrial research that workers are more productive and lose fewer days due to health problems when provisions are made for regular exer- cise. Retrospective analyses of weight regain as a fimction of energy expended in physical activity indicated a threshold for weight maintenance of 11.23 kcal (47 kJ)/kg of body weight/day. This corresponds to an average of 80 min/day of moderate activity or 35 min/day of vigorous activity added to a sedentary life- style (Schoeller et al., 1997~. As indicated, this would be considered the thresh- old level and would likely need to be higher (either longer time periods or greater intensity) to effect weight loss. There is good evidence that peak rates of lipid oxidation are achieved at exercise intensities of approximately 45 percent of VO2,nax (Bergman and Brooks, 1999; Brooks, 1998; Wolfe, 19981. . Behavioral modify 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 a result of modifiable habits or behaviors and that by changing these behaviors, weight can be lost and weight loss can be maintained. The modifications that need to be made are: increased activity, decreased energy
RESPONSE TO THE MILITARY'S QUESTIONS 115 intake, and improved diet quality. In addition, the individual needs to learn to effectively deal with stress and identify situations that may trigger excessive intake or inactivity. · Net dietary energy deft 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. While balanced macronutrient diets are usually recommended, the composition of the diet may vary to suit individual preferences and health concerns that may need to be addressed. There is no scientific consensus on the ideal dietary composition, but extremes of individual macronutrients should be avoided. For military personnel who stand to lose their livelihood if they cannot reduce their weight, options such as high- protein diets should not be precluded. Recent data suggest that these types of diets may better preserve lean body mass, lower insulin levels, and enhance energy expenditure (protein has the highest thermal effect of feeding). A potential downside to high-protein diets, particularly if they are quite low in carbohydrate, is that there may be changes In levels of potassium and other cations. Evidence suggests that the initial weight that is lost on high-protein diets is mostly fluid and thus, dehydration is a risk, particularly for military pilots. . Education. Information on nutrition principles, food-portion control, and the need for energy balance is essential for individuals to develop appropri- ate eating behaviors. . Psychological Support. Any weight-management program is likely to be more successful if it is accompanied by structured support mechanisms (e.g., from professional counselors, commanders, coworkers, and family). · Environmental changes. The services should take measures to change the environments that foster underactivity and overconsumption of energy. Ex- amples of environmental changes include putting low-fat, healthy snacks in vending machines; increasing the variety of low-fat, low-calorie entrees in base dining facilities; selecting commercial food establishments for base contracts that provide a variety of low-fat, healthy menu items; and encouraging the con- sumption of low-fat, low-calorie snacks during working hours. Environmental changes that promote greater activity are also essential (e.g., using stairs rather than elevators and escalators). The environment includes the home, the work- place, and the community. · Structured monitoring. The long-term success of weight-loss programs appears to depend on a specific and deliberate follow-up program. This struc- tured follow-up should include monitoring body weight with weigh-ins at least weekly during weight loss and monthly during maintenance, monitoring food intake, and monitoring physical activity. Keeping a diary or record that includes this information, along with notations on feelings and challenges, can also be useful. The frequency of monitoring is usually weekly until new habits and be-
116 WEIGHT MANAGEMENT haviors are well established. Abler that, less Dequent monitoring is needed unless the individual encounters difficulties and needs to get back on track. Sustaining Weight Loss Most studies in which patients are not provided weight-maintenance assis- tance following achievement of weight-loss goals show that complete weight regain will occur in a majority of the patients within 5 years (Stalonas et al., 1984; Wadden et al., 1989~. A recent review of studies on the effectiveness of weight-maintenance strategies show that programs that incorporate continued professional guidance, skills training for coping with challenges, enhanced so- cial support, enhanced aerobic exercise, and techniques for sustaining behavior change lower the rate of relapse (Perri et al., 1993~. Although such strategies do not ensure success, the outcome is much more favorable. Considering that these studies were conducted with patients in the general population where relapse is undesirable, but often not punitive, makes the results even more compelling for the military where failure to maintain weight loss can have serious consequences for career progression. A successful program for sustaining weight loss should include the follow- ing components: . Physical activity is an essential component for long-term, sustained weight loss. Studies suggest that expenditure of at least 2,000 kcal (8,368 kJ) to 3,000 kcal (12,558 kJ) per week from exercise is necessary to prevent regain of lost weight (Klem et al., 1997; Schoeller et al., 1997~. This is in addition to the normal daily activities of sedentary individuals. . Permanent lifestyle and behavioral modifications are important for maintaining energy balance. The individual needs practice in~problem solving and coping skills that are essential to balance daily energy intake and habitual levels of physical activity. This includes portion control, selecting foods lower in fat and calories, and consistently sustaining higher levels of daily physical activity. Sustained professional guidance, support, and feedback are essential for the maintenance ofthese skills. · Self-monitoring is important to success in weight maintenance. Indi- viduals who have been overweight need to weigh themselves at least once a week and record their weight. They should also be encouraged to periodically (about every 3 months) keep a 3-day diary of the type and amounts of foods consumed and the type and amounts of physical activity performed. The diary information can provide counselors with important clues on problem areas and highlight necessary changes in the diet and activity level needed to support weight maintenance. · Continuous structured support is necessary for weight maintenance. At a minimum, an individual embarking on a weight-maintenance program, in addi-
RESPONSE TO THE AlILITARY'S QUESTIONS 117 tion to self-monitoring, should have follow-up visits or counseling via phone or the lnternet every 2 to 4 weeks for the first 3 months, depending on the difficulty in maintaining a stable healthy weight, and every 1 to 2 months thereafter. QUESTION 2 How do age and gender influence success ir' weight-management programs? Should age be considered ir' weight/fat standards and in weighI-mar~agemer~t programs and interventions? Age Research indicates that percent body fat increases with age even if weight has not changed. The current upper limits of DOD standards of 26 percent fat in men and 36 percent fat in women, however, are well within the limits of the healthy percent body-fat range even for men and women as old as 60 to 79 years of age. However, since the individual services all have body-fat limits more stringent than the DOD upper limits, increases with age up to the DOD limit appear to be appropriate. Weight loss is more difficult with age due to decreases in physical activity, strength, and endurance without concomitant decreases in energy intake, cou- pled with decreases in lean body mass and increases (either absolute or relative) in percent body fat. Energy requirements may be reduced due to decreased lean body mass; therefore, energy intake must be carefully controlled. If the goal of the military is to maintain health, there should not be age-related BMI increases. However, increases in the allowable percent fat with increasing age are reason- able, but should not exceed the maximum of 36 percent in women and 26 per- cent in men. If the goal is performance, BMI and fat increases may not affect performance in some military occupations. (This is an area that needs further research.) In such occupational specialties, it may be reasonable to rely on per- formance-based physical training tests. If the goal is military appearance, there is little data to suggest that appearance standards are closely related to perform- ance, health, fitness, or nutrition (IOM, 1998~. However, from both an appear- ance and a health perspective, abdominal circumference should be used as an objective measure. Upper body adiposity as measured by abdominal circumfer- ence has been shown to be a separate risk factor for mortality and coronary heart disease. Current National Institutes of Health guidelines for maximum abdomi- nal girths are 102 cm (approximately 40 in) for men and 89 cm (approximately 35 in) for women.
118 WEIGHT MANAGEMENT Gender Women, because of their smaller body size, specific adipose tissue stores, and lower lean body mass, automatically have a higher percent body fat than men at the same BMI. In addition, excessive weight gain during pregnancy, as well as hormonal and metabolic changes after pregnancy and menopause, may be associated with higher body fat. This may make weight loss more difficult for women. Preventive measures would include counseling to keep pregnancy weight gain within the recommended range (IOM, 1990, 1 992b). QUESTION 3 Wlz~cl' strategies would be most and least effective in a military setting? Should military weight/fat loss programs involve direct participation interven- tions or only monitoring and guidance? *hould military programs be more proactive in identifying and discouraging ineffective or dangerous weigl~t-loss practices? Is a warning or cautionary zone prior to enrollment in a weigl~t- control program an effective strategy? When should dug time be authorized for participation in intervention strategies for weight/fat loss? Most and Least Effective Strategies The effective strategies for a weight/fat loss program would be the same regardless of whether the setting is military or civilian. However, the implemen- tation of some of these strategies could be facilitated in the military environ- mer~t, particularly physical fitness, exercise, and behavior modification. The safest program designed for weight loss and maintenance is an increase of energy expenditure through exercise and daily activity coupled with control or reduction of energy intake, behavior modification, and lifestyle changes. A key factor in the control of energy intake is behavior modificationindividuals who have an overweight problem have a pattern of food consumption and/or energy expenditure that contributes to positive energy balance. The primary difficulty in the military setting would be in providing structured follow-up due to the mobility of the military population. When diet and exercise are insufficient, the addition of certain prescription drugs may be useful as an adjunct, but the use of drugs should be carefully monitored and controlled. A person whose overweight is severe enough to warrant drugs (BMI > 30) is likely to require the drugs on a long-term basis. Such individuals may have genetic or other etiologies of obesity that make it difficult to adhere to lifestyle modification programs. In such cases, drug therapy may alter the biochemistry of the body sufficiently to allow them to adhere to a diet and exercise program that will bring them into compliance with weight regulations.
RESPONSE TO TTIE MILITARY'S QUESTIONS Direct Participation Interventions versus Monitoring and Guidance 119 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. It is important that overweight individuals be counseled for individualized diet modification and exercise and be continually monitored. Do-it-yourself pamphlets may be useful to some people, but many individuals need one-on-one or group contact with competent counselors to address both diet and exercise. Weight loss and weight-loss maintenance pro- grams have high rates of failure. The goal is to develop permanent behavior modification. Long-term follow-up is clearly needed for individuals to maintain their weight loss. Innovative strategies, perhaps with centralized dietitians or other counselors who can follow military personnel via the Internet, might be devel- oped. Since recidivism in overweight people is high, the military might consider mandating routine follow-up for anyone who has at any time exceeded the weight standards. While drastic, a focus on constant follow-up and feedback may prevent weight regain or identify a problem very early in its course, thus making it easier to rectify. There is a correlation between frequency of monitoring and success in weight loss and maintenance of weight loss. A comprehensive program that individualizes the degree of direct participation intervention will increase the success rate of weight/fat loss and support an improved level of weight main- tenance. If only monitoring and guidance are provided, individuals may seek help from unqualified nonmilitary weight-loss sources or pursue other unhealthy weight-loss approaches to meet their monitoring goals. Individuals' use of prescription drugs or nonprescription supplements unknown to their military health-care providers could have negative health consequences. Identifying and Discouraging Ineffective or Dangerous Weight-Loss Practices The military setting is unique in providing a strong disciplinary incentive to achieve and maintain a healthy body weight and body-fat content. Few employ- ment environments have standards for weight and percent body fat and the authority to enforce them by affecting promotion and retention. In fact, the incentive is so strong that individuals in the military have been observed to practice high-risk crash dieting in order to pass weigh-ins. It is appropriate for military weight programs to collect infonnation and evaluate weight-loss practices of overweight (as well as normal-weight) individuals as a component of their medical evaluation. Research reports (McNulty, 1997a, 1997b, 2001; Peterson et al., 1995) demonstrate Mat unhealthy eating and purging
120 WEIGHT MANAGEMENT behaviors are much more prevalent among military personnel compared with civilian populations. One method to reduce the incidence of dangerous practices is more frequent weigh-ins and an emphasis on appropriate diet and physical activity patterns at all times as part of a military lifestyle. Not only is this strategy in the individual's best interest, but also the military is responsible for the health and welfare of all uniformed personnel and must bear the cost of care for individuals who may be injured by unsafe weight-loss practices. Is A Warning or Cautionary Zone Prior to Enrollment in a Weight-Control Program an Effective Strategy? The use of a warning or cautionary zone in a military weight-control pro- gram, the Air Force has a 3-month warning period now in effect, appears to be an excellent strategy. A significant number of individuals are capable of correcting a marginal overweight condition with appropriate support. The restrictions associated with being assigned to a military weight/fat-loss program are very punitive to the individual and costly to the military service. Those who are able to solve their overweight/fat problems by themselves (or with minimal help) in a timely manner should be given the chance to accomplish this goal without being assigned to the military weight/fat-loss program with its attendant consequences. In addition, a strong, preventive weight-control effort should be added to military public health programs (beginning with initial entry training) to encourage young military personnel to monitor their body weight and seek help early if they find they are gaining weight. Authorizing Duty Time for Participation in Intervention Strategies for Weight/Fat Loss Certain tasks associated with the weight/fat loss program should be accomp-lished during duty time. They include any medical examination and tests that are appropriate before being assigned to the program, as well as counseling and monitoring. A weight-loss program should be viewed as treatment for a medical condition and, as such, be given the same priority as treatment for other medical conditions. Given the benefits of exercise for long- term obesity prevention, long-term health outcomes, and possibly for enhanced mental performance, the military might consider mandatory exercise at fixed times each day or other schemes to ensure that the vast majority of military personnel exercise several times per week. Current DOD policy dictates regular exercise as a part of the duty day. This policy should be mandatory rather than at the unit commander's discretion. Unit commanders should provide (or require) regular exercise to ensure a high level of fitness and readiness. Allowing duty time for participation in associated ac- tivities of weight-management programs, such as exercise classes, support group
RESPONSE TO THE MILITARY'S QUESTIONS 121 sessions, and classes that teach appropriate dietary selection and new food preparation techniques, should be at the discretion of the unit commander. Such activities could be viewed as part of a healthy life style and the individual should be expected to do these tasks on their own time in the same manner as individu- als who maintain a healthy weight. QUESTION 4 To what extent should weight-control programs/policies be standardized across the services versus tailored to the individual service, installation, or unit? What are the advantages and disadvantages of standardization'? Is the provision of state-of-tl~e-art- techniques and knowledge a rationale for stan- dardization? Lower rates of recruitment, increased attrition of those who enter over- weight, and reduced retention of skilled, highly trained older personnel threaten the long-term welfare and readiness of U.S. military forces. Therefore, the sub- committee provides the following responses regarding the standardization of weight-control policies. Extent of Standardization Across the Services versus Tailored to an Individual Service The specifics of implementation of weight-control policies and programs 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, on overseas bases). However, they could be standardized across the ser- vices to a significant extent as indicated below. A limited number of military centers should be identified to provide scientifically-validated body composition evaluations (IOM, 1 992a). Body Composition Standards The current DOD target for body fat, with a maximum body fat of 36 per- cent for women and 26 percent for men, seems appropriate based on considera- tions of health and chronic disease risk. This percentage of body fat should be acceptable if the fitness test is passed (IOM, 1998~. Cut-off points for the maxi- mum weight-for-height standards should reflect BMI categories that are consis- tent with the guidelines released by the National Heart, Lung and Blood Institute (NHLBI, 19981. A BMI < 18.5 constitutes underweight, a BMI of 18.5 to 24.9 constitutes healthy weight, a BMI of 25.0 to 29.9 constitutes overweight, and a BMI > 30.0 constitutes obesity. A BMI consistent with overweight does not by itself indicate that an individual is overfat. Additional testing must be done
122 WEIGHT MANAGEMENT to determine whether the excess weight in such individuals consists of fat or of lean mass. This is especially relevant because research has linked BMI to injury rates in initial entry training (Jones et al., 1992~. In several small studies, an in- creased BMI was associated with reduced performance in 1- and 2-mile runs, sit-ups, and push-ups by men, and also was associated with an increased injury rate during initial entry training. Body Composition Measurements New technologies for measuring body composition should be adopted ser- vice-wide as they become available, once they are validated for accuracy and ease of use. Appearance Standard The DOD appearance standard is articulated in DOD Directive 1308.1, DOD Physical Fitness and Body Fat Program (DOD, 19959. This document states that ". . . maintaining desirable body composition is an integral part of physical fitness, general health, and military appearance" (p. 2~. Further, Army Regulation 600-9 (U.S. Army, 1987) states that soldiers should present a physi- cal appearance in uniform "that is trim and smart" and that enlarged waistlines detract from a good military appearance. The need to develop objective criteria has been highlighted previously (IOM, 1992a, 1998~. The subcommittee com- mends the military for its recent adoption of waist circumference as a criteria for proper appearance (DOD, 2002), although research is needed to clarify whether the present appearance policy unfairly penalizes certain individuals (e.g., those of Hispanic heritage, female gender, older age) (Ellis et al., 1997; Thomas et al., 1997~. The only objective health-based standard the subcommittee can offer that relates to appearance is that waist circumference should not exceed 40 inches in men and 35 inches in women. Weight-Management Counselors Those responsible for weight-control programs should be certified and their training should be standardized. The number of certified weight-management counselors should be increased in each of the military branches. These counsel- ors should be experienced in weight management issues that are specific to gen- der, ethnic background, and age. lnternet-Based Weight-Management Programs Web-based weight-management programs should be developed that are portable and consistent DOD-wide so that counseling, records, and support tech-
RESPONSE TO THE MILITARY'S QUESTIONS 123 niques move with military personnel when they are assigned to a permanent change of station. What Are the Advantages and Disadvantages of Standardization? The advantages of standardization are that all military personnel would have access to equivalent weight-management assistance and that the incorpora- tion 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 autonomy within the branches of the 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 eval- uation, which would in turn protect DOD investments in each soldier. Although programs would need to be tailored to some degree for the various military settings, all programs need to be multidisciplinary and comprehensive (e.g., all should incorporate the elements of successful programs as discussed earlier). QUESTION 5 How can diet be effectively deal! with as a weight-management component ir' the military setting? Should pharmacological treatment (anorexiants) be considered for use in the military? In what cases? Whalfactors bear on this decision? Diet counseling needs to be administered by individuals fully trained in weight-management concepts and supported by appropriate professional person- nel. 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 consump- tion are imperative. In any case, nutrition and lifestyle education are paramount and should be provided early in the initial entry training period and reinforced periodically. The development of distance-based education 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., BMI > 30 or BMI > 27 with comorbidities and who are in military operational specialties that do not preclude the use of central nervous system-active drugs. Current prescription
124 WEIGHT MANAGEMENT weight-loss drugs appear to have minimal side effects; long-term use during an individual's military career may need to be considered. QUESTION 6 How should resistiveness to weight/fa' control be dealt with? In the context of the military use of the term, resistiveness is a condition that generally refers to a genotype and/or a phenotype that is obesity-prone. An individual may have physiological factors that favor obesity (e.g., family history of obesity), thus making weight loss much more difficult. These individuals can lose weight, but usually have to work harder and may need additional assistance in the program and in the structured follow-up. Such individuals have a higher risk of being unresponsive to lifestyle modification; drug therapy may be the most efficient and effective long-term option for their treatment. QUESTION 7 Bleat are the knowledge gaps in weighI-management programs relative to the military? What research is needed? Chapter 6 has been partly dedicated to research needs from a health and weight-loss effectiveness perspective. This report does not address the funda- mental issues of the relationship of body weight/fat standards to performance, nor does it consider the impact of military service policies on manpower needs. Additional research on the impact of modest overweight/overfat on performance in various military occupational specialties is recommended to address these issues.