We aimed to assess the influence of the Mediterranean Diet adherence and physical activity (PA) on body composition, with a particular focus on bone health, in young patients with celiac disease (CD). The CD group (n = 59) included children with CD with a long (>18 months, n = 41) or recent (<18 months, n = 18) adherence to a gluten-free diet (GFD). The non-celiac group (n = 40) included non-celiac children. After adjusting for potential confounders, the CD group showed lower body weight (p = 0.034), lean mass (p = 0.003), bone mineral content (p = 0.006), and bone Z-score (p = 0.036) than non-celiac children, even when the model was further adjusted for adherence to a GFD for at least 18 months. Among CD children, spending greater time in vigorous physical activity was associated with higher lean mass (p = 0.020) and bone mineral density with evidence of statistical significance (p = 0.078) regardless of the time they followed a GFD. In addition, a greater Mediterranean Diet adherence was associated with a higher bone Z-score (p = 0.020). Moreover, lean mass was strongly associated with bone mineral density and independently explained 12% of its variability (p < 0.001). These findings suggest the importance of correctly monitoring lifestyle in children with CD regarding dietary habits and PA levels to improve lean mass and, consequently, bone quality in this population.

Background: Maternal obesity is associated with altered polyunsaturated fatty acid (PUFA) status during pregnancy and may programme offspring adiposity, yet the contribution of specific n-3 and n-6 PUFAs across gestation and in cord blood to childhood body composition remains incompletely understood. We investigated these associations between maternal PUFA status during pregnancy and offspring obesity-related outcomes at 8.5 years. Methods: Here, we analysed data of 172 mother–child pairs from the PREOBE cohort, grouped by maternal pregestational body mass index (BMI) as normal weight (NW, n = 84), overweight (OW, n = 47), or obese (OB, n = 41). Plasma phospholipid PUFAs were quantified at 24, 34, and 40 weeks of gestation and in cord blood. At 8.5 years, children underwent anthropometry and body-composition assessment by skinfolds and bioelectrical impedance, remaining 104 mother–child pairs with valid data. Associations analyses included ANOVA/ANCOVA adjusted by confounders variables, unadjusted bivariate Spearman rank correlations with Benjamini–Hochberg False Discovery Rate (FDR) correction, and pooled robust linear regression. Results: Compared with NW mothers, OW and OB mothers showed lower α-linolenic acid (ALA) and docosahexaenoic acid (DHA) and higher n-6 PUFAs and n-6/n-3 ratios during pregnancy. Cord γ-linolenic acid (GLA) was inversely associated with several adiposity measures in the NW and OW groups after FDR correction. No correlation in the OB group met the FDR threshold; the inverse cord GLA–fat-free mass index (FFMI) association was nominal only (ρ = −0.52, p = 0.016, q = 0.688). In pooled regression models, cord GLA was inversely associated with BMI-for-age z-score, waist circumference z-score, waist-to-height ratio, body fat mass percentage, and fat mass index (FMI), whereas maternal GLA at 40 weeks was positively associated with body fat mass percentage and FMI. These pooled estimates do not establish group-specific effects. Conclusions: Maternal and cord-blood PUFA profiles were associated with childhood body composition, with patterns that varied descriptively by sampling time and maternal BMI group. These observational findings do not establish causality, protection, or differences between groups in the strength of association. Mechanistic and interventional research is required before individualised long-chain PUFA monitoring or supplementation can be recommended for obesity prevention.