Associations Between Sedentary Time, Physical Activity, and Dual-Energy X-ray Absorptiometry Measures of Total Body, Android, and Gynoid Fat Mass in Children

24-h Movement Guidelines and Overweight and Obesity Indicators in Toddlers, Children and Adolescents: A Systematic Review and Meta-Analysis

BACKGROUND

Engaging in physical activity increases energy expenditure, reducing total body fat. Time spent in sedentary behaviours is associated with overweight and obesity, and adequate sleep duration is associated with improved body composition. This systematic review aimed to analyse the relationship between compliance with the 24-h movement guidelines and obesity indicators in toddlers, children and adolescents.

METHODS

A systematic review and meta-analysis was conducted. PubMed, Web of Science and Scopus were searched from inception to December 2021. Cross-sectional and prospective studies that analysed the relationship between 24-h movement guidelines and overweight and obesity written in English, French, Portuguese or Spanish were included. PROSPERO registration number is CRD42022298316.

RESULTS

The associations between meeting the 24-h movement guidelines and standardised body mass index were null in the two studies for toddlers. Seven studies analysed the relationship between compliance with the 24-h movement guidelines and overweight and obesity among preschool children. Of these seven studies, six found no association between compliance with 24-h movement guidelines and body composition. Among children and adolescents, 15 articles were analysed. Of these 15 studies, in seven, it was found that children and adolescents who meet the 24-h movement guidelines were more likely to have lower risks of overweight and obesity. The meta-analysis yielded a pooled OR = 0.80 (95% CI = 0.68 to 0.95, p = 0.012, I² = 70.5%) in favour of compliant participants. Regarding participants' age groups, compliance with 24-h movement guidelines seems to exert greater benefits on overweight and obesity indicators among children-adolescents (OR = 0.62, p = 0.008) compared to participants at preschool (OR = 1.00, p = 0.931) and toddlers (OR = 0.91, p = 0.853).

CONCLUSION

Most included studies have not observed a significant relationship between compliance with the 24-h movement guidelines and overweight and obesity in toddlers, children and adolescents.

The association between serum copper and obesity and all-cause mortality: the NHANES 2011-2016

Excessive serum copper has multiple effects on human health, while the association between copper and obesity remains unclear. The objective of this study is to examine the associations of serum copper concentrations with obesity and adiposity measures, including body fat composition and distribution among adults in the USA. This analysis utilized data from the National Health and Nutrition Examination Survey (NHANES) (2011-2016). A total of 7285 adults aged 18 years or older who had serum copper measures were included in this cross-sectional study. Multi-linear regression and logistic regression were used to estimate the independent risky effect of copper on fat deposition and all-cause mortality. Moreover, these associations were analyzed in stratification analysis by gender, age, and physical activity (PA). Generally, we found that participants who were females, non-Hispanic Black, or with inactive PA tended to have a higher serum level of copper. In addition, we observed positive associations between serum copper and adiposity measurements. Furthermore, a serum copper level higher than 133.9 μg/dL was a risk factor for all-cause mortality, which doubled the odds ratio of all-cause mortality compared to the normal serum copper level. Serum copper was positively associated with fat deposition of whole body and regional parts, and all-cause mortality. Furthermore, the effects of copper on fat distribution were also significant and could be modified by age, gender, and PA.

Changes in Adiposity without Impacting Bone Health in Nine- to Twelve-Year-Old Children with Overweight and Obesity after a One-Year Family-Centered Lifestyle Behavior Intervention

Background: Few family-centered lifestyle interventions (FCLIs) for children with overweight or obesity (OW/OB) have assessed regional adiposity and bone health. This study assessed changes in adiposity in 9- to 12-year olds with OW/OB in a 1-year FCLI. Methods: Children were randomized to FCLI (six registered dietitian-led sessions) or no intervention (Control, CTRL). The FCLI focused on physical activity, nutrition education, and behavioral counseling children with families present. Assessments occurred at baseline and every 3 months for 1 year to assess changes in waist circumference (WC), body mass index for age-and-sex Z-scores (BAZ), body composition (dual-energy x-ray absorptiometry), and cardiometabolic biomarkers. Mixed models were used to determine the effects of group and time or group-by-time interactions for all outcomes. Results: Sixty children (age: 11.1 ± 1.1 years, BAZ: 2.7 ± 0.6) were enrolled; 55 participants (n = 28 CTRL, n = 27 FCLI) completed the study. There were no between group differences from baseline to follow-up for any measure. The FCLI group had significant decreases in BAZ over 12 months (-0.18 ± 0.27, p = 0.03) but not CTRL (-0.05 ± 0.32, p = 0.92). WC and android fat mass did not change in FCLI (p > 0.20) but increased in CTRL (p < 0.02). Whole body bone area, content, and areal bone mineral density (aBMD) increased in both groups (p < 0.010); whole body aBMD Z-score decreased by 5.8% and 1.6% in CTRL and FCLI, respectively (p < 0.001). There were no significant within group changes in biomarkers. Conclusion: The FCLI resulted in small reductions in BAZ and a plateau in android fat mass, which suggest that FCLIs are suitable as an intervention for 9- to 12-year-old children with OW/OB. Clinical Trial Registration number: NCT01290016.

A comparison of the associations between bone health and three different intensities of accelerometer-derived habitual physical activity in children and adolescents: a systematic review

Positive associations have been identified between bone outcomes and accelerometer-derived moderate (MPA) and vigorous (VPA) physical activity (PA) in youth; however, it remains unclear which intensity is most beneficial. This systematic review aimed to summarise accelerometer-derived methods used to estimate habitual PA in children and adolescents and determine whether the magnitude of association was consistently stronger for a particular intensity (MPA/MVPA/VPA). Observational studies assessing associations between accelerometer-derived MPA and/or MVPA and VPA with bone outcomes in children and adolescents (≤ 18 years) were identified in MEDLINE, EMBASE, Web of Science, SPORTDiscus and the Cochrane Central Register of Controlled Trials. Thirty articles were included (total n = 20,613 (10,077 males), 4-18 years). Chi-square tests determined whether the proportion of significant associations and strongest within-study associations differed significantly between intensities. Results demonstrated that accelerometer methods were highly variable between studies. Of the 570 associations analysed, 186 were significant (p < 0.05). The proportion of within-study strongest associations differed by PA intensity (3 × 2 χ2 = 86.6, p < 0.001) and was significantly higher for VPA (39%) compared to MVPA (5%; 2 × 2 χ2 = 55.3, p < 0.001) and MPA (9%, 2 × 2 χ2 = 49.1, p < 0.001). Results indicated a greater benefit of VPA over MPA/MVPA; however, variability in accelerometer-derived methods used prevents the precise bone-benefitting amount of VPA from being identified. Long epochs and numerous intensity cut-point definitions mean that bone-relevant PA has likely been missed or misclassified in this population. Future research should explore the use of shorter epochs (1 s) and identify bone-specific activity intensities, rather than using pre-defined activity classifications more relevant to cardiovascular health.

Using Body Composition Groups to Identify Children and Adolescents at Risk of Dyslipidemia

The impact of body composition on the early origin of chronic diseases is an increasingly appreciated phenomenon. Little is known about the characteristics of children with varying body composition. The aim of this study was to investigate serum lipid profiles and other characteristics in relation to body composition. The data of 1394 participants (aged 6 to <18 years) of the observational general population-based Austrian LEAD Study have been analyzed. Body composition groups were defined by appendicular lean mass (ALMI) and fat mass (FMI) indices assessed by DXA. Serum lipid profiles (triglycerides, LDL-c, HDL-c) and other characteristics (e.g., prematurity, smoke exposure, physical activity, nutrition) were investigated in these body composition groups. Different body composition groups, which are not distinguishable by BMI, exist. Children with high ALMI and high FMI showed higher triglycerides and LDL-c, but lower HDL-c levels. In contrast, levels did not differ between those with high FMI but low (or normal) ALMI, and other body composition groups. BMI should be interpreted cautiously, and body composition should be measured by more precise techniques. In particular, children and adolescents with high FMI who have concomitantly high ALMI should be followed closely in future studies to investigate whether they are at increased risk of cardiovascular problems.

Sex-specific differences in somatic investment and strategies of physical activity among Portuguese schoolchildren

OBJECTIVES

Physical activity (PA) is required for healthy growth, development, and maturation and plays an important role in the prevention of overweight and obesity in childhood and adolescence. Sex-differences in PA levels are well documented, with boys spending more time in PA, especially in moderate-to-vigorous activities. Following the Life History Theory, our aim is to study if PA affects the fat tissues increases during childhood and juvenile phases in both sexes.

METHODS

Time spent in sedentary, light, and moderate-to-vigorous PA levels were measured in a sample of 415 Portuguese children and juveniles (207 females/208 males; aged 6-11 years), using an accelerometer for 7 days. Skinfolds related with body fat were objectively collected and socioeconomic status factors were reported using a parental questionnaire.

RESULTS

The outcomes show that girls' and boys' fat variables increased during the end of the childhood and the juvenile phase. However, these variables were differently affected by PA. Girls increased fat variables with the sedentary activity while boys decreased fat variables with moderate-to-vigorous PA. Alike, active boys but not girls reduced the fat increase tendency with age.

CONCLUSIONS

Although both sexes displayed a general fat increment with age, moderate-to-vigorous PA dampens the increase only in boys. In fact, active girls increased body fat in the same manner as non-active girls. From an evolutionary perspective, it could explain sex-specific somatic strategies related to future reproduction or, with future mating and intrasexual competition.

Associations of Physical Activity and Sedentary Behaviour Assessed by Accelerometer with Body Composition among Children and Adolescents: A Scoping Review

The possible adverse health effects of reduced physical activity (PA) on children and adolescents have been extensively documented as a result of the global obesity epidemic. However, the research has sometimes led to controversial results, due to the different methods used for the assessment of PA. The main aim of this review was to evaluate the association between PA and body composition parameters based on quantitative PA studies using the same equipment (Actigraph accelerometer) and cutoffs (Evenson’s). A literature review was undertaken using PUBMED and Scopus databases. Subjects aged 6–15 were considered separately by sex. Weighted multiple regression analyses were conducted. From the analysis of fourteen selected articles, it emerged that 35.7% did not evaluate the association of sedentary time (ST) and moderate-to-vigorous physical activity (MVPA) with body composition, while the remaining 64.3% found a negative association of MVPA with BMI and fat mass with different trends according to sex. Furthermore, only 7.1% of these studies identified a positive association between ST and fat percentage. Based on the regression analyses conducted on the literature data, ST and MVPA were found to be significant predictors of body composition parameters, in addition to age and sex. Further studies using standardized methodologies to assess PA and body composition are needed. The inclusion of sex-disaggregated data may also be crucial to understand this phenomenon and to provide stronger evidence of the determinants of body composition in order to prevent the risk of obesity.

Association of objectively measured physical activity and bone health in children and adolescents: a systematic review and narrative synthesis

The influence of day-to-day physical activity on bone in adolescence has not been well characterized. Forty articles were identified that assessed the relationship between accelerometry-derived physical activity and bone outcomes in adolescents. Physical activity was positively associated with bone strength in peri-pubertal males, with less consistent evidence in females. Physical activity (PA) is recommended to optimize bone development in childhood and adolescence; however, the influence of day-to-day PA on bone development is not well defined. The aim of this review was to describe the current evidence for objectively measured PA on bone outcomes in healthy children and adolescents. MEDLINE, Embase, Cochrane Library, Scopus, Web of Science, CINAHL, PsycInfo, and ClinicalTrials.gov were searched for relevant articles up to April 2020. Studies assessing the relationship between accelerometry-derived PA and bone outcomes in adolescents (6-18 years old) were included. Two reviewers independently screened studies for eligibility, extracted data, and rated study quality. Forty articles met inclusion criteria (25 cross-sectional, 15 longitudinal). There was significant heterogeneity in accelerometry methodology and bone outcomes measured. Studies in males indicated a significant, positive relationship between moderate to vigorous PA (MVPA) and bone outcomes at the hip and femur, particularly during the peri-pubertal years. The results for MVPA and bone outcomes in females were mixed. There was a paucity of longitudinal studies using pQCT and a lack of data regarding how light PA and/or impact activity influences bone outcomes. The current evidence suggests that objectively measured MVPA is positively associated with bone outcomes in children and adolescents, especially in males. However, inconsistencies in methodology make it difficult to determine the amount and type of PA that leads to favorable bone outcomes. Given that the majority of research has been conducted in Caucasian adolescents, further research is needed in minority populations.

Phase Angle is Determined by Body Composition and Cardiorespiratory Fitness in Adolescents

The phase angle is used to evaluate nutritional status and is an indicator of cellular health. Cardiorespiratory fitness and body composition are strong indicators of health during adolescence. We aimed to evaluate if body composition and cardiorespiratory fitness have an association with phase angle among adolescents. 203 girls and 220 boys (12.8±1.3 years) were evaluated. Peak height velocity, percentage fat mass, fat-free mass, cardiorespiratory fitness, and phase angle measurements were collected. Linear regression adjusted by peak height velocity was used to verify if predictor variables were associated with phase angle among adolescents. Phase angle showed correlation with fat-free mass (girls: r=0.42 and boys: r=0.37); with percent fat mass (girls: r=0.23); and with cardiorespiratory fitness (boys: r=0.19). Linear regression showed that percentage fat mass (in girls) and cardiorespiratory fitness (in boys) had an effect of 11 and 17% in phase angle, respectively, while fat-free mass had an effect of 22 and 26% in phase angle for girls and boys, respectively. Changes in phase angle seem to be more associated with the percentage fat mass in girls, cardiorespiratory fitness in boys, and fat-free mass in both when controlled by peak height velocity.

Effects of Synbiotic Supplement on Human Gut Microbiota, Body Composition and Weight Loss in Obesity

Targeting gut microbiota with synbiotics (probiotic supplements containing prebiotic components) is emerging as a promising intervention in the comprehensive nutritional approach to reducing obesity. Weight loss resulting from low-carbohydrate high-protein diets can be significant but has also been linked to potentially negative health effects due to increased bacterial fermentation of undigested protein within the colon and subsequent changes in gut microbiota composition. Correcting obesity-induced disruption of gut microbiota with synbiotics can be more effective than supplementation with probiotics alone because prebiotic components of synbiotics support the growth and survival of positive bacteria therein. The purpose of this placebo-controlled intervention clinical trial was to evaluate the effects of a synbiotic supplement on the composition, richness and diversity of gut microbiota and associations of microbial species with body composition parameters and biomarkers of obesity in human subjects participating in a weight loss program. The probiotic component of the synbiotic used in the study contained Lactobacillus acidophilus, Bifidobacterium lactis, Bifidobacterium longum, and Bifidobacterium bifidum and the prebiotic component was a galactooligosaccharide mixture. The results showed no statistically significant differences in body composition (body mass, BMI, body fat mass, body fat percentage, body lean mass, and bone mineral content) between the placebo and synbiotic groups at the end of the clinical trial (3-month intervention, 20 human subjects participating in weight loss intervention based on a low-carbohydrate, high-protein, reduced energy diet). Synbiotic supplementation increased the abundance of gut bacteria associated with positive health effects, especially Bifidobacterium and Lactobacillus, and it also appeared to increase the gut microbiota richness. A decreasing trend in the gut microbiota diversity in the placebo and synbiotic groups was observed at the end of trial, which may imply the effect of the high-protein low-carbohydrate diet used in the weight loss program. Regression analysis performed to correlate abundance of species following supplementation with body composition parameters and biomarkers of obesity found an association between a decrease over time in blood glucose and an increase in Lactobacillus abundance, particularly in the synbiotic group. However, the decrease over time in body mass, BMI, waist circumstance, and body fat mass was associated with a decrease in Bifidobacterium abundance. The results obtained support the conclusion that synbiotic supplement used in this clinical trial modulates human gut microbiota by increasing abundance of potentially beneficial microbial species.

Abdominal Adiposity and Total Body Fat as Predictors of Cardiometabolic Health in Children and Adolescents With Obesity

Objective: We aimed to assess the role of adipose tissue distribution in cardiometabolic risk (in particular insulin sensitivity) in a population of children and adolescents with obesity. Methods: In this cross-sectional study, participants were 479 children and adolescents with obesity (322 boys and 157 girls) aged 3 to 18 years attending the Children's Hospital at Zhejiang University School of Medicine (Hangzhou, China). Clinical assessments included anthropometry, body composition (DXA scans), carotid artery ultrasounds, and OGTT. Insulin sensitivity was assessed using the Matsuda index. Participants were stratified into groups by sex and pubertal stage. Key predictors were DXA-derived android-to-gynoid-fat ratio (A/G) and total body fat percentage (TBF%). Results: Irrespective of sex and pubertal stage, there was a strong association between increasing A/G (i.e., greater abdominal adiposity) and lower insulin sensitivity. In multivariable models, every 0.1 increase in A/G was associated with a reduction in insulin sensitivity in prepubertal boys [-29% (95% CI -36%, -20%); p < 0.0001], pubertal boys [-13% (95% CI -21%, -6%); p = 0.001], and pubertal girls [-16% (95% CI -24%, -6%); p = 0.002]. In contrast, TBF% was not associated with insulin sensitivity when A/G was adjusted for, irrespective of pubertal stage or sex. In addition, every 0.1 increase in A/G was associated with increased likelihood of dyslipidemia in prepubertal boys [adjusted odds ratio (aOR) 1.62 (95% CI 1.05, 2.49)], impaired glucose tolerance in pubertal boys [aOR 1.64 (95% CI 1.07, 2.51)] and pubertal girls [aOR 1.81 (95% CI 1.10, 2.98)], and odds of NAFLD in both prepubertal [aOR 2.57 (95% CI 1.56, 4.21)] and pubertal [aOR 1.69 (95% CI 1.18, 2.40)] boys. In contrast, higher TBF% was only associated with higher fasting insulin and ALT in pubertal boys, being also predictive of NAFLD in this group [aOR 1.15 per percentage point (95% CI 1.06, 1.26)], but was not associated with the likelihood of other cardiometabolic outcomes assessed in any group. Conclusions: A/G is a much stronger independent predictor of cardiometabolic risk factors in children and adolescents with obesity in China, particularly glucose metabolism.

Effect of Chemotherapy on Dual-Energy X-ray Absorptiometry (DXA) Body Composition Precision Error in Head and Neck Cancer Patients

BACKGROUND

Precision error in dual-energy X-ray absorptiometry (DXA) is defined as difference in results due to instrumental and technical factors given no biologic change. The aim of this study is to compare precision error in DXA body composition scans in head and neck cancer patients before and 2 months after chemotherapy.

METHODOLOGY

A total of 34 male head and neck cancer patients with normal body mass index (BMI) were prospectively enrolled and all patients received 2 consecutive DXA scans both before and after 2 months of chemotherapy for a total of 4 scans. The precision error of 3 DXA body composition values (lean mass, fat mass, and bone mineral content) was calculated for total body and 5 body regions (arms, legs, trunk, android, and gynoid). Precision errors before and after treatment were compared using generalized estimating equation model.

RESULTS

There was no significant change in precision error for the DXA total body composition values following chemotherapy; lean mass (0.33%-0.40%, p = 0.179), total fat mass (1.39%-1.70%, p = 0.259) and total bone mineral content (0.42%-0.56%, p = 0.243). However, there were significant changes in regional precision error; trunk lean mass (1.19%-1.77%, p = 0.014) and android fat mass (2.17%-3.72%, p = 0.046).

CONCLUSIONS

For head and neck cancer patients, precision error of DXA total body composition values did not change significantly following chemotherapy; however, there were significant changes in fat mass in the android and lean mass in the trunk. Caution should be exercised when interpreting longitudinal DXA body composition data in those body parts.