Longitudinal trends and gender differences in physical fitness and lifestyle factors in career U.S. Navy personnel (1983-1994)

This study examines long-term health and physical readiness trends in the U.S. Navy. We mailed lifestyle questionnaires to all participants in baseline studies between 1983 and 1989 who were still on active duty in 1994. Commands provided body composition and physical readiness test scores for the participants. Two longitudinal cohorts were created: an 8-year sample (N = 640) with matched data from 1986, 1989, and 1994; and an 11-year sample (N = 1,576), with data from 1983 and 1994. Analyses of both cohorts revealed significant improvements in cardiovascular fitness, muscle strength, exercise, lean body mass, dietary habits, and sleep, as well as significant decreases in tobacco and alcohol use and job stress. However, hypertension rates, percentage of body fat, and body mass index increased over time. Women's scores were significantly better than men's on a number of factors. Overall, these findings suggest that the Navy's health promotion efforts have had a significant positive effect on the fitness and health behaviors of career Navy men and women.

Evaluation of a four- versus six-week length of stay in the Navy's alcohol treatment program.

OBJECTIVE: Attempts to balance escalating health care costs with resource downsizing have prompted alcohol treatment directors in the U.S. Navy to consider reducing the standard length of stay in treatment. The objectives of this study were to (1) determine whether a 4-week inpatient treatment program is as effective as a 6-week program, and (2) explore the potential for matching patients to a 4- or 6-week program according to the severity of their condition at intake. METHOD: A total of 2,823 active-duty alcohol-dependent inpatients (2,685 men, 138 women) at 12 Navy treatment facilities participated in the evaluation. All facilities conducted a 6-week program until data had been collected for 1,380 participants; they then switched to a 4-week program (n = 1,443). Background information and clinical profile were obtained when patients entered treatment; 1-year outcome data (e.g., alcohol use, behavior problems, job performance, quality of life) were obtained from participants, work supervisors and aftercare advisors. Hierarchical multiple regression analyses were used to assess the effect of length of stay on outcome and to examine patient-program interactions. RESULTS: The single best predictor of success at 1 year was months of aftercare attendance. Program membership failed to explain any of the observed differences in the criterion measures, once the effects of other predictors had been taken into account. Severity of condition and patient-program interactions were likewise nonsignificant. CONCLUSIONS: It was concluded that a reduction in length of stay from 6 weeks to 4 weeks in the Navy's inpatient alcohol treatment program would not have an adverse effect on outcome.

Effects of chromium picolinate on body composition.

OBJECTIVE: This study explored the efficacy of chromium picolinate as a fat-reduction aid for obese individuals enrolled in a physical exercise program. EXPERIMENTAL DESIGN: The study employed a double-blind, placebo-controlled protocol and lasted for 16 weeks. SETTING: The physical conditioning programs were conducted on Navy bases (gymnasium, athletic field, etc.) and met a minimum of three times per week for at least 30 minutes of aerobic exercise. PARTICIPANTS: Participants were healthy, active-duty Navy personnel (79 men, 16 women) who exceeded the Navy's percent body fat standards of 22% fat for men, 30% for women. Mean age was 30.3 years; racial distribution was 76% white, 16% black, and 8% other. Comparisons between the 95 study completers and the 109 dropouts revealed no significant differences in demographics or baseline percent body fat. INTERVENTIONS: Bottles of capsules containing either 400 micrograms chromium picolinate or a placebo were distributed to the designated individuals by their fitness program coordinator. Participants took one capsule per day and kept a log of their daily exercise activities. They also completed a pre-post questionnaire concerning their health and lifestyle habits. MEASURES: Primary outcome measures were percent body fat, body weight, and lean body mass. Percent body fat was computed from body circumference measurements and height. Analyses controlled for diet and exercise. RESULTS: At the end of 16 weeks, the group as a whole had lost a small amount of weight and body fat. However, the chromium group failed to show a significantly greater reduction in either percent body fat or body weight, or a greater increase in lean body mass, than did the placebo group. CONCLUSIONS: It was concluded that chromium picolinate was ineffective in enhancing body fat reduction in this group and could not be recommended as an adjuvant to Navy weight-loss programs in general.

Evaluation of the Navy's obesity treatment program.

This study evaluated the overall effectiveness of the Navy's three-tiered obesity treatment program and compared effectiveness across the three treatment levels. Height, weight, and body circumference measurements were obtained from 369 program participants at baseline and follow-up (6 weeks, 6 months, 12 months). Results demonstrated a significant and sustained reduction in percent body fat in all three program tiers, but the absolute losses at the end of 12 months were small: -3.7% fat for men, -4.5% fat for women. The level III tier, which employs a multidimensional approach to treatment, was the most effective program, even after differences in enrollees' initial percent body fat were taken into account. Changes in the approach to treatment and development of a supportive, long-term, behaviorally based aftercare program are recommended.

Survey of the Navy's three-tiered obesity treatment program.

The Navy's diverse, three-tiered obesity treatment program is described. Level I (command-directed) programs rely primarily on group exercise to treat obesity; most level II (outpatient counseling) and level III (6-week inpatient) programs are modeled on Overeaters Anonymous and devote substantial amounts of time to group discussion, behavior modification, and nutrition education. Lack of funding or staffing has prevented many level II facilities from conducting a weight-management program, however. Further research might explore the potential for level II to provide a cost-effective middle ground for obesity treatment.

Nutrition knowledge of active-duty Navy personnel.

As evidence continues to mount implicating diet in the etiology of disease, the US Navy is developing nutrition education programs designed to reflect the consolidated dietary recommendations of national expert agencies. The purpose of this study was to provide a baseline assessment of the level of nutrition knowledge among Navy personnel. Forty true/false questions were developed to test nutrition knowledge as conveyed by the Navy's instructional manual for nutrition educators. The questionnaire was mailed to a representative sample of all active-duty Navy personnel. Usable questionnaires were received from 2,938 participants (72.7% response rate). Mean number of correct items was 26.1 (65%). Nutrition knowledge was higher among older respondents, more highly educated personnel, whites, officers, women, and overweight individuals. Knowledge was weakest in the areas of calories/food intake and carbohydrates and strongest on vitamins/minerals and fiber. Program managers were recommended to intensify efforts to reach low-scoring subgroups, place more emphasis on the role of complex carbohydrates, disseminate guidelines for using nutrition labels on products, and develop point-of-choice nutrition education interventions for military dining facilities.

Prevalence of elevated serum cholesterol in personnel of the U.S. Navy.

Fasting blood lipid profiles were collected for 5,487 active duty Navy men and women presenting for routine physical examinations. Mean serum cholesterol for the sample (mean age 33.6 years) was 208.2 milligrams per deciliter (mg per dL). Cholesterol level increased with age, decreased with education, and was higher in men than in women. Using the Navy's own risk cutpoints for total cholesterol (200 mg per dL for ages 18-24, 220 mg per dL for ages 25 and older), 36.9 percent of the sample were found to be at risk. When the percentage of the population at risk was computed using the guidelines suggested by the National Institutes of Health Consensus Conference, rather than the Navy's cutpoints, results were almost identical (36.3 percent at risk); when based on the National Cholesterol Education Program's recommended cutpoints, the percent at risk was considerably higher (55.4 percent). Risk estimates that included LDL- or HDL-cholesterol risk levels (or both) also were higher. A larger percentage of Navy personnel were at risk because of total cholesterol than were persons in an age-adjusted national sample. However, because routine examinations generally are not given until first reenlistment, the Navy sample underrepresented younger service members, and results may overestimate the prevalence of hypercholesterolemia in the Navy at large. The author draws attention to the problem of lack of standardization in cholesterol testing and notes that the Navy does not yet participate in an external quality control program. The difficulty in setting appropriate risk cutpoints, given the complexity of factors that must be considered as well as the general unreliability of cholesterol tests, is also discussed.

Dietary factors related to physical fitness among navy shipboard men.

Abstract This study examines the relationship between habitual dietary practices and performance on the physical readiness test required of active duty Navy personnel. Participants were 1,013 men (mean age = 26.2 years) stationed aboard nine Navy ships. The men completed a self-report survey of lifestyle and dietary habits and were evaluated on four tests of physical fitness: 1.5-mile Run, Sit-ups, Sit-reach, and Percent Body Fat. A standardized Overall Fitness score was also computed for each person. Results indicated that the participants tended to skip breakfast, ingest moderate amounts of caffeine, and favor a high-fat, low-fiber diet. Fitness scores were associated with a number of dietary variables, including caffeine intake, between-meal snacking, and overeating (all negatively related to fitness, p <.01), and having a general "nutrition orientation" (positively related to fitness, p <.001). The relationships were confounded by the influence of age, exercise, and smoking, but even after controlling for these, diet was a significant predictor of fitness (p <.001).