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: 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.

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.

The prevalence of obesity among children is rising and over the years we can estimate the severity of medical issues at adult age. According to the latest studies and also personal experience we are already seeing the first signs of diabetes, high blood pressure and non-alcoholic fatty liver disease (NAFLD) in children and adolescents. The excess of sugar and refined carbohydrates associated with a sedentary lifestyle has multiple negative effects for organism and high risk of comorbidities, especially for dental health of children. We also notice problems in the dental field and here we refer to dental caries and dental demineralization. Aim of the study: In this observational study we set out to find out the possible correlation between obesity in children and dental problems by evaluating the body mass index, percentile, and a self-assessment method for dental problems using the ADA’s Caries Risk Assessment. Materials and Methods: In this study 51 children with ages between 7 and 17 years old were evaluated in the nutrition office. The degree of obesity was established using the body mass index and percentile. Each participant then had to fill out and ADA’s Caries Risk Assessment form for patients over 6 years of age. Results: Out of the 42 children with obesity or overweight that completed ADA’s Caries Risk Assessment form, 50% associate dental problems, more precisely carious lesions, according to the answers received using the ADA form, the high prevalence is correlated with sugar consumption. Conclusions: The analysis of the study lot highlighted a significant correlation between weight and oral health, which means that a poor diet, rich in refined sugars, may lead to obesity and also dental lesions. Improving collaboration between general and oral health professionals is essential to improve health and also to prevent the development of more serious comorbidities.