Objectives: Pediatric obesity represents a significant public health challenge, requiring accurate and accessible tools for assessing body composition in pediatric populations. This systematic review (PROSPERO CRD42024592366) compares the methodological accuracy and clinical utility of bioelectrical impedance analysis (BIA) and dual x-ray absorptiometry (DXA) in evaluating obesity among children and adolescents. Methods: Utilizing a comprehensive search across PubMed, EMBASE, and Web of Science between 1 January 2014 and 31 December 2024, we identified 28 studies meeting our inclusion criteria. The studies included involved participants aged 2–17 years with obesity and compared BIA with DXA as the reference standard. The exclusion criteria were studies focusing on adults, those that assessed BC solely using anthropometry, and those that did not report primary outcomes relevant to the comparison of BIA vs. DXA. Results: The findings reveal that despite recent technological advances improving BIA’s precision, it consistently underestimates body fat percentage and fat mass, particularly in overweight and obese pediatric populations. DXA it is often used as a reference method in the evaluation of whole-body composition due to its higher accuracy and reliability. BIA offers significant practical advantages in accessibility, cost-effectiveness, and portability, but enhancements are needed to improve its accuracy for individual-level assessments. Conclusions: While BIA shows promise as a practical tool for body composition assessment in children, its accuracy varies significantly by device type. Multi-frequency segmental analyzers, such as InBody 720, demonstrate better agreement with DXA, whereas simpler models tend to underestimate fat mass. Therefore, conclusions regarding BIA performance should be device-specific and its clinical utility should be carefully weighed based on the technology used.

Background: Vitamin D plays an important role in maintaining bone health with numerous benefits for extraskeletal health as well. Objectives: We aimed to assess the prevalence of vitamin D deficiency in children (0–18 years old) in a tertiary hospital in Romania between August 2019 and January 2024 and to investigate the role of adequate supplementation in this vulnerable population. Methods: The serum 25(OH)D levels were measured using a chemiluminescence binding assay. Results: A total of 744 participants were included in this study: 396 female (53.23%) and 348 male (46.77%). The serum levels of 25(OH)D ranged between 2.2 and 125.4 ng/mL, with a mean value of 27.4 ng/mL and a median value of 23.5 ng/mL. According to the cutoff values for the definition of vitamin D status (severe deficiency: <10 ng/mL, deficiency: <20 ng/mL, insufficiency: 20–29 ng/mL, and sufficiency: ≥30 ng/mL), the sample consisted of 77 (10.34%) cases of severe deficiency, 221 (29.7%) cases of deficiency, 194 (26.07%) cases of insufficiency, and 245 (32.93%) cases of sufficiency. There were seven cases of hypervitaminosis D with values above 100 ng/mL. The mean values (and corresponding 95% confidence intervals, CIs) were as follows: 27.85 ng/mL [25.95–29.76] in the males, 22.45 ng/mL [25.12–28.82] in the females, 24.82 ng/mL [21.86–27.77] in the spring, 28.62 ng/mL [26.42–30.81] in the summer, 32.30 ng/mL [29.16–35.44] in the autumn, and 24.01 ng/mL [21.57–26.44] in the winter. We observed a notable decline in the serum 25(OH)D levels with age, with 82.08% of the children in the age group above 6 years old having serum 25(OH)D levels below 30 ng/mL. In obese subjects, a higher prevalence of hypovitaminosis D was observed compared to non-obese subjects, with a mean value of 19.54 [17.50–21.57] ng/mL in obese children versus 28.89 [27.39–30.40] ng/mL in normal weight children. Conclusions: In our sample, the mean serum concentration of 25(OH)D was 27.4 ng/mL. Notably, 66.11% of the cases demonstrated varying degrees of hypovitaminosis D, with a significantly higher prevalence of 86.16% observed in the obese group. Healthcare providers should prioritize routine screening for vitamin D levels in pediatric patients with obesity to facilitate timely intervention and personalized supplementation strategies tailored to individual needs

Obesity in the pediatric population has become a public health problem with an increasing prevalence in recent years. The gut microbiota and its metabolites, especially short-chain fatty acids (SCFAs), play vital roles in the development of pediatric obesity. This manuscript aims to highlight the link between the gut microbiota and obesity by examining microbial imbalances, such as altered Firmicutes/Bacteroidetes ratios and altered SCFA production, especially butyrate, propionate, and acetate. Advances in genomic technologies, such as 16S rRNA sequencing, have enabled personalized treatments and detailed profiling of microbial diversity. This review includes not only preclinical studies but also clinical trials of interventions, such as probiotics, synbiotics, prebiotics, and butyrate supplements. These may modify the microbiota and SCFA levels to reduce obesity and related conditions, such as metabolic syndrome and precocious puberty. Future research should focus on using advanced genomic sequencing techniques to develop new therapeutic strategies, as well as on creating a complex predictive algorithm for assessing metabolic risk in pediatric patients with obesity, an innovation that can be extended to other metabolic conditions.

Background/Objectives: The aim was to identify patterns of autonomic and neuroendocrine reactivity to an immersive virtual reality (VR) social-emotional stressor and explore their associations with perceived stress and eating behavior. Methods: This one-group pretest–posttest study included 30 children and adolescents with obesity (15 boys and 15 girls), aged 8 to 17 years. The VR protocol consisted of two consecutive phases: a 5 min relaxation phase using the Forest application and a 5 min stimulation phase using a cognitively engaging VR game designed to elicit social-emotional stress. Physiological responses were measured using heart rate variability (HRV) indices and salivary stress biomarkers, including cortisol and alpha amylase. Subjective stress and eating responses were assessed via visual analogue scales (VAS) administered immediately post-exposure. The Three-Factor Eating Questionnaire (TFEQ-R21C) was used to evaluate cognitive restraint (CR), uncontrolled eating (UE), and emotional eating (EE). Results: The cortisol reactivity was blunted and may reflect both the attenuated HPA axis responsiveness characteristic of pediatric obesity and the moderate psychological challenge of the VR stressor used in this study. Two distinct autonomic response patterns were identified via exploratory factor analysis: (1) parasympathetic reactivity, associated with increased RMSSD and SDNN and decreased LF/HF, and (2) sympathetic activation, associated with increased heart rate and alpha-amylase levels and reduced RR intervals. Parasympathetic reactivity was correlated with lower perceived stress and anxiety, but also paradoxically with higher uncontrolled eating (UE). In contrast, sympathetic activation was associated with greater cognitive restraint (CR) and higher anxiety ratings. Conclusions: This study demonstrates that immersive VR game exposure elicits measurable autonomic and subjective stress responses in children and adolescents with obesity, and that individual differences in physiological reactivity are relevantly associated with eating behavior traits. The findings suggest that parasympathetic and sympathetic profiles may represent distinct behavioral patterns with implications for targeted intervention.

Pediatric obesity is a growing public health concern, significantly increasing the risk of metabolic and cardiovascular comorbidities. Background/Objectives: This study aims to explore the burden of obesity, its associated comorbidities, and resting metabolic rate (RMR) assessed by indirect calorimetry among children and adolescents in a cohort of 223 participants from Nord-East of Romania. Methods: A cross-sectional study was conducted among 223 children and adolescents (aged 4–18 years) who were diagnosed with obesity at Saint Mary Emergency Children’s Hospital Iași. Anthropometric measurements, clinical assessment, and biochemical parameters were recorded. RMR was measured by indirect calorimetry, using the Fitmate Pro Metabolic Technology (Cosmed, Rome, Italy), under a stable environment for 15 min, following a fasting period of minimum 6–8 h. Data were analyzed using SPSS 22.0, applying descriptive statistics and Pearson correlations. Results: A total of 223 participants were included in the analysis, with a mean age of 12.03 ± 3.32 years (range 4–17 years) and a mean body mass index (BMI) of 31.21 ± 5.84 kg/m². The average RMR was 1687.5 ± 425.5 kcal/day, with higher values in males compared with females. RMR showed significant positive correlations with age (r = 0.60), BMI (r = 0.51), waist circumference (r = 0.67), and fat mass measured with a three-site formula technique (r = 0.51) and systolic (r = 0.45) and diastolic blood pressure (r = 0.19), all with p < 0.001. A weak inverse correlation was observed between RMR and the fitness index (r = −0.24, p < 0.001), indicating an association between lower fitness scores and higher RMR values. RMR showed no significant correlation with fasting glucose or lipid levels, indicating that metabolic rate was more influenced by body composition than by biochemical markers. Conclusions: Pediatric obesity is strongly linked to multiple comorbidities, emphasizing the need for early detection and targeted interventions. Higher BMI and central adiposity were associated with increased RMR. Indirect calorimetry provides valuable insights into the metabolic profile of children with obesity and can inform individualized management strategies.

Background: Childhood obesity is increasingly associated with gut microbiome dysbiosis. This systematic review (PROSPERO CRD420251131354) evaluates evidence from studies published between 2020 and 2026 assessing how nutritional and lifestyle interventions influence gut microbiota in children with obesity. Methods: A systematic search of PubMed, EMBASE and EBSCO identified 21 interventional studies involving children aged 5–18 years with obesity, with the last search conducted in April 2026. Interventions comprised prebiotics, probiotics, synbiotics, postbiotics, high-fiber diets, calorie-restricted dietary approaches, and lifestyle modifications such as physical activity. Microbiome outcomes were analyzed using 16S rRNA sequencing, quantitative real-time polymerase chain reaction (qPCR), or metagenomics. Risk of bias was evaluated using the RoB 2 and ROBINS-I (version 2) tools. Due to substantial heterogeneity in study design, participant characteristics, intervention types, and analytical methods, a meta-analysis was not feasible. Results: Across 21 studies, nutritional interventions included measurable but heterogeneous alterations in gut microbiome composition. Inulin supplementation was associated with a significant increase in alpha diversity and with higher relative abundances of Bifidobacterium, Blautia, Megasphaera, Subdoligranulum, and Eubacterium coprostanoligenes. Synbiotic supplementation increased Prevotella and Dialister and reduced the Firmicutes/Bacteroidetes ratio. High-fiber dietary interventions increased Faecalibacterium, Bifidobacterium, and Clostridium, while reducing Bacteroides, and were associated with shifts in metabolic pathways related to carbohydrate, lipid, and nucleotide metabolism. Calorie-restricted diets and combined diet–exercise interventions increased beneficial taxa such as Akkermansia muciniphila, improved microbial diversity, and correlated with favorable metabolic and anthropometric outcomes. Overall, nutritional and lifestyle interventions in pediatric obesity were associated with taxon-specific and context-dependent microbiome changes, rather than uniform restructuring. Conclusions: Nutritional interventions can modulate gut microbiota diversity, composition, and predicted function in pediatric obesity; however, the observed effects vary substantially across studies. The limited number of trials, small sample sizes, and methodological heterogeneity underscore the need for larger, standardized studies to better define clinical and therapeutic implications.