Nutrition Knowledge Is Associated With Diet Quality Among US Army Soldiers

OBJECTIVE

Examine the relationship between nutrition knowledge, diet quality, and eating behavior among active-duty US Army Soldiers.

METHODS

Cross-sectional study with data collection in February 2018 via paper surveys during the validation of the Military Eating Behavior Survey.

RESULTS

Among 440 US Army Soldiers, nutrition knowledge was positively and significantly associated with diet quality (b = 0.29, P < 0.001). For every 1-point increase in nutrition knowledge, the Healthy Eating Index-2015 score was expected to increase by 0.29 points. Nutrition knowledge was not significantly associated with skipping breakfast (odds ratio, 1.01; 95% confidence interval, 0.98-1.04) or dining out (odds ratio, 1.01; 95% confidence interval, 0.98-1.03).

CONCLUSIONS AND IMPLICATIONS

The outcomes of this study warrant further investigation to determine what interventions provide the strongest outcomes for improving nutrition knowledge and diet quality, as well as create and support an environment that enhances healthy behaviors regarding nutrition that lead to improved diet quality among active-duty Soldiers.

The relationship between sleep, pain,and musculoskeletal injuries in US Army Soldiers

INTRODUCTION

The purpose of this study was to investigate the relationship between sleep and pain in military personnel and to determine if metrics of sleep and pain intensity differ between the injured and uninjured in this population.

METHODS

Active-duty US Army Soldiers (n=308; 26.8±6.5 years, 82% male) from the 2nd Infantry Division, Joint Base Lewis-McChord, Washington, and 101st Airborne Division, Fort Campbell, Kentucky, completed the Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), and questionnaires about current musculoskeletal injuries and pain intensity (0=no pain to 10=worst imaginable pain). Pearson correlation coefficients were used to assess the association between pain and sleep. Differences in sleep and pain between injured and uninjured participants were determined using an analysis of covariance.

RESULTS

Pain intensity was positively correlated with sleep quality (global PSQI score, r=0.337, p<0.001) and daytime sleepiness (ESS score, r=0.163, p=0.005), and negatively associated with sleep duration (r=-0.118, p=0.039). Injured participants accounted for 37.7% (n=116) of the study population. Injured participants reported greater pain intensity (3.7±2.5 vs 1.3±1.9, p<0.001), were older (28.5±7.4 years vs 25.8±5.7 years, p=0.001) and in the service longer (6.3±6.3 years vs 4.6±4.7 years, p=0.013) than uninjured participants. Injured participants had higher global PSQI scores (9.0±4.1 vs 6.4±3.4, p<0.001), including each of the seven PSQI components (all p<0.050), and reported sleeping less per night than uninjured participants (5.7±1.3 hours vs 6.1±1.2 hours, p=0.026).

CONCLUSION

These data demonstrate that pain intensity is associated with sleep in active-duty US Army Soldiers and that those who report a musculoskeletal injury, regardless of age and time in service, report poorer sleep quality, shorter sleep durations, and greater levels of pain than uninjured Soldiers.

Characterizing Relationships Among the Cognitive, Physical, Social-emotional, and Health-related Traits of Military Personnel

INTRODUCTION

Personnel engaged in high-stakes occupations, such as military personnel, law enforcement, and emergency first responders, must sustain performance through a range of environmental stressors. To maximize the effectiveness of military personnel, an a priori understanding of traits can help predict their physical and cognitive performance under stress and adversity. This work developed and assessed a suite of measures that have the potential to predict performance during operational scenarios. These measures were designed to characterize four specific trait-based domains: cognitive, health, physical, and social-emotional.

MATERIALS AND METHODS

One hundred and ninety-one active duty U.S. Army soldiers completed interleaved questionnaire-based, seated task-based, and physical task-based measures over a period of 3-5 days. Redundancy analysis, dimensionality reduction, and network analyses revealed several patterns of interest.

RESULTS

First, unique variable analysis revealed a minimally redundant battery of instruments. Second, principal component analysis showed that metrics tended to cluster together in three to five components within each domain. Finally, analyses of cross-domain associations using network analysis illustrated that cognitive, health, physical, and social-emotional domains showed strong construct solidarity.

CONCLUSIONS

The present battery of metrics presents a fieldable toolkit that may be used to predict operational performance that can be clustered into separate components or used independently. It will aid predictive algorithm development aimed to identify critical predictors of individual military personnel and small-unit performance outcomes.

Healthy Eating Score-7 as a Measure of Diet Quality in a Military Population

OBJECTIVE

Identify potential revisions to the Healthy Eating Score (HES-5) that improve associations with the Healthy Eating Index (HEI) -2015 total and component scores.

METHODS

Pearson r correlations were determined from soldiers' (n = 433) survey data, including the HES, proposed additional questions, and the Block Food Frequency Questionnaire.

RESULTS

Adding sugar-sweetened beverages and energy drink questions (HES-7) strengthened the HES and HEI-2015 correlation (HES-5; r = 0.42, n = 433, r² = 0.18, P < 0.001) (HES-7; r = 0.52, r² = 0.27, P < 0.001). The HES components and Block Food Frequency Questionnaire consumption correlations were as follows: quantity of fruit (r = 0.37, r² = 0.14, P < 0.001), vegetables (r = 0.41, r² = 0.17, P < 0.001), whole grains (r = 0.35, r² = 0.12 P < 0.001), dairy (r = 0.34, r² = 0.12, P < 0.001), fish (r = 0.31, r² = 0.10, P < 0.001), and energy drink (r = 0.59, r² = 0.35, P < 0.001).

CONCLUSIONS AND IMPLICATIONS

HES-7 had the strongest correlation with HEI-2015. Future studies can explore if including consumption quantity in the HES improves its representation of diet quality.

Barriers to Nutrition Interventions in Army Dining Facilities: A Qualitative Study

INTRODUCTION

Interventions that encourage good nutrition-related behaviors in the dining environment can potentially influence the health of large numbers of military personnel. Thus, the Army has studied the effectiveness of implementing nutrition education and dining facility (DFAC) changes that included healthier recipes, revised menus, and population-specific point-of-choice labeling, but successful intervention implementation largely depends on the foodservice employees' understanding, knowledge, and desire to sustain changes. This phenomenological, qualitative study aimed to better understand common barriers to the implementation and sustainment of DFAC-based nutrition interventions at two U.S. Army DFACs.

MATERIALS AND METHODS

Focus group sessions (n = 168 participants) ranging from 60 to 90 minutes in length were conducted at two large DFACs on three separate occasions every 4 months from May 2015 to January 2016 among the foodservice staff during intervention implementation. Focus group transcripts were analyzed using NVivo 11 software. Researchers conducted multiple rounds of coding following an iterative process until four principal themes emerged.

RESULTS

Principal themes related to the foodservice employees' experience during the nutrition intervention revealed barriers to a successful implementation related to (1) nutrition knowledge deficits, (2) inadequate culinary training, (3) poor management practices, and (4) low staff morale.

CONCLUSION

A lack of foodservice staff training and education is a significant contributor to implementation barriers. Future interventions should increase engagement with foodservice employees during intervention planning and implementation phases with a structured and tailored nutrition education and culinary skill training program. Addressing these barriers may enhance staff morale and promote intervention adherence.

Development and Validation of the Military Eating Behavior Survey

OBJECTIVE

To describe the Military Eating Behavior Survey (MEBS), developed, and validated for use in military populations.

DESIGN

Questionnaire development using a 6-phase approach that included item generation, subject matter expert review, cognitive interviewing, factor analysis, test-retest reliability testing, and parallel forms testing.

SETTING

US Army soldiers were surveyed at 8 military bases from 2016 to 2019 (n = 1,561).

MAIN OUTCOME MEASURE

Content, face, and construct validity and reliability of the MEBS.

ANALYSIS

Item variability, internal consistency, and exploratory factor analysis using principal coordinates analysis, orthogonal varimax rotation, and scree test (correlation coefficient and Cronbach alpha), as well as consistency and agreement (intraclass correlation coefficient) of test-retest reliability and parallel forms reliability.

RESULTS

Over 6 phases of testing, a comprehensive tool to examine military eating habits and mediators of eating behavior was developed. Questionnaire length was reduced from 277 items to 133 items (43 eating habits; 90 mediating behaviors). Factor analysis identified 14 eating habit scales (hunger, satiety, food craving, meal pattern, restraint, diet rigidity, emotional eating, fast/slow eating rate, environmental triggers, situational eating, supplement use, and food choice) and 8 mediating factor scales (body composition strategy, perceived stress, food access, sleep habits, military fitness, physical activity, military body image, and nutrition knowledge).

CONCLUSIONS AND IMPLICATIONS

The MEBS provides a new approach for assessing eating behavior in military personnel and may be used to inform and evaluate health promotion interventions related to weight management, performance optimization, and military readiness and resiliency.

Exceeding body composition standards is associated with a more negative body image and increased weight cycling in active duty U.S. soldiers

Negative body image is more often identified in individuals with overweight or obesity. More than 65% of U.S. soldiers have a body mass index (BMI) that classifies them with overweight or obesity. Additionally, all soldiers must meet body composition and physical fitness standards which may increase the risk of negative body image. This cross-sectional study aimed to identify associations between compliance with body composition standards, body image, and weight cycling through surveying 969 active-duty soldiers (86% male, 24.0 ± 5.5 years of age, BMI 26.0 ± 3.6 kg/m²). Compliance with body composition standards was measured by whether a soldier had ever taken and failed the circumference-based body fat assessment. Weight cycling was self-reported as ≥3 weight fluctuations of ≥5% of body weight during their military career. Multivariate linear and logistic regression models were used to examine the relationship between compliance with body composition standards, body image, weight cycling, and sociodemographic characteristics while controlling for BMI. Failing the circumference-based body fat assessment was associated with increased concern with conforming to military image. Negative body image was associated with higher odds of weight cycling. Further examination is warranted to understand the effects of body composition standards on soldiers' body image and weight cycling.

Eating Behaviors Are Associated With Physical Fitness and Body Composition Among US Army Soldiers

OBJECTIVE

Examine associations between soldiers' eating behaviors, compliance with body composition and fitness standards, and physical performance.

DESIGN

Cross-sectional study.

SETTING

Eight Army installations.

PARTICIPANTS

US Army Soldiers (n = 1,591; 84% male).

MAIN OUTCOME MEASURES

Characteristics, eating behaviors, compliance with body composition and physical fitness standards, and fitness level were assessed via questionnaire.

ANALYSIS

Bivariate and multivariable logistic regression.

RESULTS

Eating mostly at a dining facility was associated with lower odds of body composition failure (odds ratio [OR], 0.44; 95% confidence interval [CI], 0.26-0.73); whereas, eating at a fast rate (OR, 1.51; 95% CI, 1.05-2.17) or often/always ignoring satiety cues (OR, 2.12; 95% CI, 1.06-4.27) was associated with higher odds of body composition failure. Eating mostly fast-food/convenience meals (OR, 1.75; 95% CI, 1.19-2.59) and eating at a fast rate (OR, 1.42; 95% CI, 1.04-1.93) was associated with higher odds of physical fitness failure. Skipping breakfast was associated with lower odds of high physical performance (OR, 0.41; 95% CI, 0.23-0.74); whereas, nutrition education was associated with higher odds of high physical performance (OR, 1.02; 95% CI, 1.01-1.04).

CONCLUSIONS AND IMPLICATIONS

As eating behaviors are modifiable, findings suggest opportunities for improving the specificity of Army health promotion and education programs.

Stressful Life Changes and Their Relationship to Nutrition-Related Health Outcomes Among US Army Soldiers

Stressful life changes may tax people's adaptive capacity. We sought to determine if and when experiences of stressful life changes were associated with increased odds of adverse nutrition-related health outcomes among US Army soldiers relative to those who did not experience the same stressful life change. An additional aim was to determine which stressful life changes had the greatest association with these outcomes and if there were gender differences in the magnitude of the associations. Stressful life changes studied included: changes in marital status, combat deployment or return from deployment, relocation, adding a child, change in rank, change in occupation, and development of a physical limitation to duty. Using longitudinal data from the Stanford Military Data Repository, which represents all active-duty soldiers aged 17-62 between 2011 and 2014 (n = 827,126), we employed an event history analysis to examine associations between stressful life changes and a subsequent diagnosis of hyperlipidemia, substantial weight gain, and weight-related separation from the Army. Marriage was associated with an increase in the odds of substantial weight gain 3 months later for both men and women. Developing a physical duty limitation was associated with an increase in the odds of a hyperlipidemia diagnosis 2 months later for both men and women, as was substantial weight gain 2 months later. Stressful life changes were also associated with increased odds of nutrition-related health outcomes, although we found gender differences in the magnitude of the associations. Findings could be used to mitigate the effects of stress on health by health professionals.

Validity of Digital and Manual Refractometers for Measuring Urine Specific Gravity During Field Operations: A Brief Report

INTRODUCTION

Dehydration can have an immediate negative impact on the performance of Soldiers in training or combat environments. Field expedient methods for assessing hydration status may be valuable for service members. Measurement of urine-specific gravity (USG) via refractometer is inexpensive, simple, fast, and a validated indicator of hydration status. Manual (MAN) and digital (DIG) refractometers are commonly used in laboratory settings however, digital (DIG) devices have not been validated in the field against MAN devices. The purpose of this study was to determine the validity and feasibility of using a DIG refractometer to assess USG compared to a MAN refractometer during a military field training exercise.

MATERIALS AND METHODS

Fifty-six military service members provided 672 urine samples during two 10-day field training exercises in central Texas. USG was assessed using a MAN and a DIG refractometer with cutoff value of ≥1.020 indicating hypohydration. The study received a non-human research determination.

RESULTS

The MAN measurements were strongly correlated with the DIG (r = 0.91, p < 0.0001) measurements. Bland-Altman analysis demonstrated agreement between the refractometers. The DIG displayed good sensitivity (93.9%) and specificity (85.8%) compared to the MAN.

CONCLUSION

The DIG refractometer used in this study was reliable and valid compared with a MAN device and was feasible for use in a field environment; however, the DIG refractometer tended to over overestimate hypohydration.

Trajectories of body mass index among active-duty U.S. Army soldiers, 2011-2014

Establishing the shape and determinants of trajectories of body mass index (BMI) among Soldiers is critical given the importance of weight management to military service requirements. To establish the shape and determinants of BMI trajectories among Soldiers, we aimed to (1) model the overall BMI trajectory of Soldiers, (2) find the most common trajectory groups among Soldiers, (3) investigate the relationship between BMI trajectories and sociodemographic and military-specific characteristics, and (4) determine if there were Soldiers with large fluctuations in BMI. The study population included all US Army Soldiers on active-duty between 2011 and 2014 who were age 17–62 (n = 827,126). With longitudinal data from the Stanford Military Data Repository, we used group-based trajectory modeling to identify the BMI trajectories of Soldiers and multinomial logistic regression to estimate associations between Soldier characteristics and trajectory membership. Four distinct BMI trajectory groups were found: increasing, decreasing, constant, and inconstant. The constant, increasing, and decreasing trajectories were similar in shape and percentage between men and women. The constant trajectory had the fewest Soldiers who exceeded weight standards or had duty limitations. The increasing trajectory was associated with marriage and fewer service years. The decreasing trajectory was associated with more service years and higher educational attainment. The inconstant trajectory differed in shape between men and women. Over 6% of men and 12% of women had fluctuations in BMI indicative of weight cycling. Understanding the characteristics associated with BMI trends may assist the Army in targeting resources aimed to improve Soldier health and combat readiness.

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Four BMI trajectory groups were found: increasing, decreasing, constant, inconstant.

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The constant trajectory had the fewest Soldiers who exceeded weight standards.

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The increasing trajectory was associated with marriage and fewer service years.

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The decreasing trajectory was associated with more service years and education.

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6% of men and 12% of women had fluctuations in BMI indicative of weight cycling.