It Is High Time for Personalized Dietary Counseling in Celiac Disease: A Systematic Review and Meta-Analysis on Body Composition

The body composition of patients with celiac disease (CD), on which the effects of a gluten-free diet (GFD) are controversial, differs from that of the average population. In this study, we aimed to compare the body composition across CD patients before a GFD, CD patients after a one-year GFD and non-celiac control subjects. A systematic search was conducted using five electronic databases up to 15 July 2021 for studies that reported at least one of the pre-specified outcomes. In meta-analyses, weighted mean differences (WMDs) with 95% confidence intervals (CIs) were calculated. A total of 25 studies were eligible for systematic review, seven of which were included in meta-analysis. During a ≥1-year GFD, fat mass of CD patients, compared to that at baseline, significantly increased (WMD = 4.1 kg, 95% CI = 1.5 to 6.6, three studies). In CD patients after a ≥1-year GFD, compared to non-celiac controls, fat mass (WMD = −5.8 kg, 95% CI = −8.7 to −2.9, three studies) and fat-free mass (WMD = −1.9 kg, 95% CI = −3.0 to −0.7, three studies) were significantly lower. In conclusion, body composition-related parameters of CD patients differ from that of the non-celiac control subjects even after a longstanding GFD