Comparison of Body Composition Assessed by Dual-Energy X-Ray Absorptiometry and BMI in Current and Former U.S. Navy Service Members

An Assessment of Daily Energy Expenditure of Navy Ship Crews and Officers Serving in the Polish Maritime Border Guard as an Indicator of Work Severity and Nutritional Security

BACKGROUND

Research on energy expenditure related to life and professional activity allows us to determine a person's energy. This study determined the value of daily energy expenditure related to the implementation of service and training tasks of crews of ships in the Polish Navy and officers of the Maritime Department of the Border Guard.

MATERIALS AND METHODS

This study included crews of two selected ships of the Polish Navy and officers of the Maritime Branch of the Border Guard. The method of analyzing heart rate changes was used to measure energy expenditure.

RESULTS

The value of daily energy expenditure related to the implementation of tasks during a cruise amounted to 3874 kcal/d for the crew of a missile frigate, and it was higher at 4031 kcal/d for the crew of a training sailing ship. Energy expenditure related to the training of ship crews staying in a port was lower, amounting to 3648 kcal/d and 3380 kcal/d, respectively. The energy expenditure of the Maritime Border Guard officers during a 12 h shift ranged from 1830 kcal/12 h to 2762 kcal/12 h. Current nutritional standards for sailors of the Polish Navy and the Border Guard officers provide an excessively high energy intake in daily food rations, which may cause overweight and obesity.

A cohort study of body mass index changes among U.S. Air Force personnel during the COVID-19 pandemic

BACKGROUND

The impact of the COVID-19 pandemic period continues to be felt, including a resulting increase in prevalence and rates of individuals with obesity within the Unites States, which had already been trending upward prior to the pandemic. This study aims to identify changes in body mass index (BMI) among the active-duty U.S. Air Force (USAF) personnel prior to and during the pandemic.

MATERIALS AND METHODS

We conducted a retrospective cohort study of USAF active-duty personnel. BMI data points were sourced from the Military Health System Data Repository and included a measure from each period: pre- (September 1, 2018 - February 28, 2020), early (March 1, 2020 - September 30, 2020), and late pandemic (October 1, 2020 - September 30, 2022). Pregnant women delivering during or one year prior to the study periods were excluded. Statistical analysis included percent change, the Stuart-Maxwell test for marginal homogeneity, and ANOVA comparing mean BMI with post-hoc mean comparisons. Additionally, the percentage change toward obese BMI was stratified by rank and occupation.

RESULTS

We identified a cohort of 111,392 active-duty USAF personnel. The overall increase in prevalence of USAF personnel with obesity over the entire study period was 44.1%. The prevalence of USAF personnel with obesity among our cohort increased by 11.6% from the pre-pandemic period to the early pandemic period (18% pre-pandemic; 20.8% early pandemic) with a 29.1% increase in prevalence from the early to late pandemic periods (20.8% early pandemic; 26.9% late pandemic). USAF aircrew members progressed to having a BMI of obese at lower rates over the same periods increasing by 7.8%, 21.3%, and 30.7%, respectively. The most prominent changes were observed among females, personnel between the ages 20 and 24, of American Indian or Alaska Native race, and in junior enlisted ranks.

CONCLUSIONS

Our analysis indicates that like the other service branches of the U.S. military, the Air Force experienced an increase in active-duty personnel with obesity during the COVID-19 pandemic period. This indicates increases in rates of service members with obesity across the U.S. armed forces, which is likely to result in decreased force readiness.

BMI changes among U.S. Navy and Marine Corps active-duty service members during the COVID-19 pandemic, 2019-2021

BACKGROUND

The COVID-19 pandemic disrupted the daily life and routines of Americans across the United States (U.S.), including those of our active-duty service members (ADSMs). Limited movement orders enacted during this time to promote social distancing prohibited access to fitness and dining facilities for ADSMs. This study aims to expand on previous work identifying changes in body mass index (BMI) among U.S. Army service members by identifying changes in body mass index (BMI) among active-duty service members from both the Navy and Marine Corps during the same time period.

METHODS

We conducted a retrospective cohort study of active-duty service members from the Navy and Marine Corps using data from the Military Health System Data Repository. BMI was calculated and categorized according to CDC guidelines both before (February 2019 - January 2020) and during the pandemic (September 2020 - June 2021). Women who were pregnant or delivered during and one year prior to the study periods were excluded. Statistical analyses included paired t-tests evaluating mean BMI, percent change, and the Stuart-Maxwell test for marginal homogeneity.

RESULTS

We identified 98,330 active-duty Sailors and 55,298 active-duty Marines for inclusion in this study. During the pandemic period the percentage of Sailors with Underweight decreased by 11%, Healthy weight decreased by 11.1%, Overweight increased by 2.1%, and the percentage of Sailors with Obesity increased by 16.5%. During this same time period, Marines with Underweight decreased by 1%, Healthy weight decreased by 16%, Overweight increased by 3.0%, and Marines with Obesity increased by 51%. The largest increases in service members with overweight and obesity observed among both cohorts were among female service members, service members under age 20, and service members with a Junior Enlisted rank.

CONCLUSIONS

Significant increases in obesity were observed amongst active-duty United States Navy and Marine Corps service members during DoD pandemic mitigation efforts. Increased rates of obesity likely effected fitness and force readiness. Future interventions should be targeted at younger, Junior-Enlisted Marines and Sailors to promote healthy lifestyles and provide education on nutrition, appropriate exercise, sleep hygiene, and stress management.

The Medical Burden of Obesity and Overweight in the US Military: Association of BMI with Clinically Diagnosed Medical Conditions in United States Military Service Members

BACKGROUND

A high BMI is associated with various medical conditions, notably type 2 diabetes, cardiovascular disease, and mental health disorders. In the US military, BMI increased linearly between 1975 and 2015.

OBJECTIVE

This cross-sectional study investigated the associations between BMI and a comprehensive range of clinically diagnosed medical conditions (CDMCs) in US military service members (SMs).

METHODS

A stratified random sample of SMs (n=26,177) completed an online questionnaire reporting their height, weight, and demographic/lifestyle characteristics. Medical conditions for 6 mo before questionnaire completion were obtained from a comprehensive military electronic medical surveillance system and grouped into 39 CDMCs covering both broad (largely systemic) and specific medical conditions. BMI was calculated as weight/height2 (kg/m2). The prevalence of CDMCs was compared among normal weight (<25.0 kg/m2), overweight (25.0-29.9 kg/m2), and obese (≥30 kg/m2) SMs.

RESULTS

After multivariable adjustment for demographic/lifestyle characteristics, higher BMI was associated with higher odds of a diagnosed medical condition in 30 of 39 CDMCs, with all 30 displaying dose-response relationships. The 5 major CDMCs with the largest odds ratios comparing obese to normal weight were endocrine/nutritional/metabolic diseases (OR=2.67, 95%CI=2.24-3.15), nervous system diseases (odds ratio [OR]=2.59, 95%CI=2.32-2.90), circulatory system diseases (OR=2.56, 95%CI=2.15-3.06), musculoskeletal system diseases (OR=1.92, 95%CI=1.76-2.09), and mental/behavioral disorders (OR=1.69, 95%CI=1.51-1.90). Compared with normal weight SMs, overweight or obese SMs had a higher number of CDMCs (1.8±1.9 vs. 2.0±2.0 and 2.5±2.3, mean ± standard deviation, respectively, P<0.01).

CONCLUSIONS

In a young, physically active population, higher BMI was associated with a host of medical conditions, even after adjustment for demographic/lifestyle characteristics. The US Department of Defense should improve nutrition education and modify other factors that contribute to overweight and obesity. This study demonstrates that the medical burden of obesity is substantial in overweight and obese SMs.

The Use of Different Anthropometric Indices to Assess the Body Composition of Young Women in Relation to the Incidence of Obesity, Sarcopenia and the Premature Mortality Risk

The objective of the study was to evaluate the stratification of young women based on the assessment of body composition according to several currently recommended anthropometric indices and parameters, as well as the presence of obesity, sarcopenic obesity and the risk of premature death. Three hundred and three young Caucasian women aged 18-25 years were included in the cross-sectional observational study. For the purposes of the study, we used the bioelectrical impedance method and applied the obtained data to calculate indices defining obesity, sarcopenic obesity and premature mortality risk (ABSI z-score). We found significant differences between indicators of total and abdominal obesity when determining the rate of risk of premature death and diagnosis of obesity. Our results also suggest that FMI and FM/FFM indices correlate excellently with fat mass and visceral adipose tissue, better than BMI. Even in the case of abdominal obesity, FMI appears to correlate relatively strongly, more so than BMI. The results of the study support the opinion that in the assessment of body composition and health status, the presence of obesity (sarcopenic obesity) and the risk of premature death, anthropometric parameters and indices focusing not only on body weight (BMI, ABSI), but also on the proportionality and distribution of fat (WC, WHR, WHtR, VFA) and muscle tissue (FFMI, SMMI, FM/FFM ratio) should be used.

Overweight BMI (25-29) in Active Duty Military: Excess Fat or More Lean Mass? A Look at the Evidence

Many active duty service members and their health care providers feel that the current body mass index (BMI) standard for diagnosing obesity, BMI ≥30 kg/m2, may unfairly overclassify as obese those with higher muscle mass. Unfortunately, a closer look at the data available for service members repeatedly demonstrates the exact opposite: we are actually underestimating the rates of obesity in service members using current BMI cutoffs when compared with body fat mass as measured by either dual-energy X-ray absorptiometry or bioelectrical impedance analysis as the gold standard. Using a lower BMI threshold and refining positive results via history, exam, labs, and/or more specific measurements of body composition would more accurately estimate body fat percentage in active duty service members while remaining convenient and scalable. Given the current obesity epidemic in our nation, this suggests the critical need for new approaches to screening, as well as treatment, of overweight and obesity in our military to improve service readiness.

Cognitive disinhibition and infrequent moderate-to-intense physical activity linked with obesity in U.S. soldiers

PURPOSE

To explore the relationship between body weight status and neurocognitive functioning in soldiers.

METHODS

U.S. soldiers (N = 109) answered survey questions and completed neurocognitive tests including simple reaction time, code substitution, procedural reaction time, go-no-go, matching to sample, code substitution recall, and four versions of the Stroop test including congruent (color and meaning of word agreed); incongruent (color and meaning of word differed); neutral (nonsense words appeared), and emotional (combat-related words such as "I.E.D" and "convoy" appeared). Self-reported heights and weights were used to calculate BMI. A BMI ≥ 30.00 kg/m² was categorized as obese. Multivariate analysis of variance was used to analyze weight status differences (p ≤ 0.05) across neurocognitive variables. Binomial logistic regression analysis with obesity as the dependent variable was used to ascertain the contributions (p ≤ 0.05) of exercise and the neurocognitive measures that differed based on weight status.

RESULTS

Twenty-nine participants (26.6%) were obese. The obese group had significantly lower scores on code substitution, and both neutral and emotional Stroop tasks. Only Stroop emotional scores, p = 0.022, OR = 0.97, and frequency of moderate/intense physical activity, p = 0.009, OR = 0.10, were significant predictors of weight status.

CONCLUSIONS

Obesity was associated with less frequent moderate/intense physical activity and compromised executive functioning, namely decrements in response inhibition. Given the design and sample size, additional research is needed to better understand the direction of the relationship between these variables and to inform research related to the treatment and prevention of obesity within military populations.

LEVEL OF EVIDENCE

Level III, case-control analytic study.

Maximum Aerobic Function: Clinical Relevance, Physiological Underpinnings, and Practical Application

The earliest humans relied on large quantities of metabolic energy from the oxidation of fatty acids to develop larger brains and bodies, prevent and reduce disease risk, extend longevity, in addition to other benefits. This was enabled through the consumption of a high fat and low-carbohydrate diet (LCD). Increased fat oxidation also supported daily bouts of prolonged, low-intensity, aerobic-based physical activity. Over the past 40-plus years, a clinical program has been developed to help people manage their lifestyles to promote increased fat oxidation as a means to improve various aspects of health and fitness that include reducing excess body fat, preventing disease, and optimizing human performance. This program is referred to as maximum aerobic function, and includes the practical application of a personalized exercise heart rate (HR) formula of low-to-moderate intensity associated with maximal fat oxidation (MFO), and without the need for laboratory evaluations. The relationship between exercise training at this HR and associated laboratory measures of MFO, health outcomes and athletic performance must be verified scientifically.

Army Body Composition Program Study Results Concerning: Enrollees Are More Over Fat Than Expected

INTRODUCTION

Whether implementation of the Army Body Composition Program (ABCP) is meeting readiness objectives is unknown.

OBJECTIVE

This study sought to primarily describe the extent of Active Duty Soldiers' over-fatness when attending the initial ABCP nutrition class at an Army Nutrition clinic in Washington State; and secondarily to describe the proportion of these Soldiers meeting metabolic syndrome (MS) criteria.

METHODS

Soldiers (189) in this cross-sectional study completed the following: a questionnaire developed for this study, anthropometric measurements, body fat assessment via AR 600-9 standards, and a laboratory blood draw for fasting glucose and lipid panel.

RESULTS

Soldiers were predominantly male (76%), obese (BMI 32 kg/m2 for males and 30 kg/m2 for females), exceeded body fat standards by 3.8% for males and 7.3% for females, and 16% had three or more risk factors meeting MS diagnostic criteria. Waist circumference was the predominant MS risk factor for males and females.

CONCLUSION

Soldiers in this study had higher body fat percentages than expected with a majority of Soldiers classified as obese. Achieving and maintaining ABCP standards may be more challenging for obese Soldiers. To maintain Soldier readiness, commanders should consider intervening earlier when signs of weight gain are observed.

Relationship between "a body shape index (ABSI)" and body composition in obese patients with type 2 diabetes

BACKGROUND

Obesity is known to be related to the development of type 2 diabetes mellitus (T2D). The most commonly used anthropometric indicator (body mass index [BMI]) presents several limitations such as the lack of possibility to distinguish adipose tissue distribution. Thus, this study examines the suitability of a body shape index (ABSI) for prediction of body composition and sarcopenic obesity in obese or overweight T2D subjects.

METHODS

Cross-sectional study in 199 overweight/obese T2D adults. Anthropometric (BMI, ABSI) and body composition (fat mass [FM], fat-free mass [FFM], fat mass index [FMI] and fat-free mass index, and the ratio FM/FFM as an index of sarcopenic obesity) data was collected, as well as metabolic parameters (glycated haemoglobin [HbA_1c], mean blood glucose, fasting plasma glucose [FPG], high-density-lipoprotein cholesterol [HDL], low-density-lipoprotein cholesterol, total cholesterol, and triglycerides [TG] levels; the ratio TG/HDL was also calculated as a surrogate marker for insulin resistance).

RESULTS

ABSI was significantly associated with age and waist circumference. It showed a statistically significant correlation with BMI exclusively in women. Regarding body composition, in men, ABSI was associated with FM (%), while in women it was associated with both FM and FFM. Both males and females groups with high ABSI scores were significantly older (men: 59.3 ± 10.8 vs 54.6 ± 10.1, p ≤ 0.05; women: 65.1 ± 9.8 vs 58.1 ± 13.3, p ≤ 0.005) and showed lower FFM values (men: 62.3 ± 9.0 vs 66.2 ± 9.3, p ≤ 0.05; women: 48.7 ± 5.6 vs 54.5 ± 8.9, p ≤ 0.001) compared with low-ABSI groups. Multiple linear regression revealed that ABSI independently predict FMI and the FM/FFM ratio in women. Sarcopenic obesity was identified in 70 (36.5%) individuals according to the FM/FFM ratio. The AUROC of ABSI was 63.1% (95% CI 54.6-71.6%; p = 0.003) and an ABSI value of 0.083 m^11/6 kg^-2/3 was the optimal threshold in discriminating patients with sarcopenic obesity (sensitivity: 48%, specificity: 73%). Moreover, a significant association between ABSI and FPG was found in men.

CONCLUSIONS

ABSI could be useful to identify visceral and sarcopenic obesity in overweight/obese adults with T2D, adding some relevant clinical information to traditional anthropometric measures.

The Prevalence of Overfat Adults and Children in the US

The overfat condition is defined as excess body fat sufficient to impair health. The problem exists in most overweight and obese individuals and can also occur in those who are normal-weight and non-obese, often due to excess abdominal fat. Despite previous indications that the prevalence overweight and obesity is leveling, these conditions are currently at their highest levels in US history. Our review estimated the number of overfat Americans at 91% for adults and 69% for children. The primary purpose of this review was to build upon previous estimations of overfat prevalence in developed countries by using new data from the Centers for Disease Control and Prevention to estimate the overfat prevalence in American adults (≥20 years) and children (2-19 years), and to expand the definition of overfat as excess body fat associated with at least one additional risk factor of impaired cardiometabolic or physical health. The secondary goals are to highlight the role of dietary sugar as a primary cause of the overfat pandemic and mention new data showing the increased prevalence of exercise that parallels the rising prevalence of overfat to further emphasize the secondary role exercise may play in fat loss. Current public health guidelines to address the overfat pandemic may require more emphasis on reducing the consumption of refined carbohydrates, including added sugars.

Overfat Adults and Children in Developed Countries: The Public Health Importance of Identifying Excess Body Fat

The global overfat pandemic is a serious public health crisis that places a substantial burden on economic resources in developed countries. The term overfat refers to the presence of excess body fat that can impair health, even for normal weight non-obese individuals. Excess body fat is associated with cardiometabolic dysfunction, a clinical situation that can progressively worsen, potentially leading to various common disease risk factors, chronic diseases, increased morbidity and mortality, and reduced quality of life. The prevalence of overfat populations in 30 of the world’s most developed countries is substantially higher than recent global estimations, with the largest growth due to a relatively recent increased number of people with excess abdominal fat. Abdominal overfat is the most unhealthful form of this condition, so it is concerning that average waist circumference measures, generally indicative of abdominal overfat, have increased. Despite a leveling off appearance of being overweight and/or obese in some developed countries, the overfat pandemic continues to grow.

Cardiometabolic Health in Submariners Returning from a 3-Month Patrol

Confined space, limited exercise equipment, rotating shift work and reduced sleep may affect cardiometabolic health in submariners. To test this hypothesis, 53 male U.S. Submariners (20–39 years) were studied before and after a 3-month routine submarine patrol. Measures included anthropometrics, dietary and physical activity, biomarkers of cardiometabolic health, energy and appetite regulation, and inflammation. Before deployment, 62% of submariners had a body fat % (BF%) ≥ 25% (obesity), and of this group, 30% met the criteria for metabolic syndrome. In obese volunteers, insulin, the homeostatic model assessment of insulin resistance (HOMA-IR), leptin, the leptin/adiponectin ratio, and pro-inflammatory chemokines growth-related oncogene and macrophage-derived chemokine were significantly higher compared to non-obese submariners. Following the patrol, a significant mean reduction in body mass (5%) and fat-mass (11%) occurred in the obese group as a result of reduced energy intake (~2000 kJ) during the patrol; and, independent of group, modest improvements in serum lipids and a mean reduction in interferon γ-induced protein 10 and monocyte chemotactic protein 1 were observed. Since 43% of the submariners remained obese, and 18% continued to meet the criteria for metabolic syndrome following the patrol, the magnitude of weight loss was insufficient to completely abolish metabolic dysfunction. Submergence up to 3-months, however, does not appear to be the cause of obesity, which is similar to that of the general population.