CT-Derived Body Composition and Diet Quality in Body Mass İndex: A Cross-Sectional Study

Introduction/Objectives: Body composition changes and diet quality may contribute to metabolic complications and graft outcomes after kidney transplantation. We evaluated the relationships between diet quality and CT-derived body composition components (skeletal muscle mass, muscle quality/myosteatosis, and visceral adiposity) and explored their associations with metabolic markers and graft function. Materials and Methods: In this single-center retrospective cross-sectional study, we included 161 adult first kidney transplant recipients (KTRs) with a functioning graft and ≥12 months of follow-up. Body composition was quantified on routine abdominal CT at the L3 level using skeletal muscle index (SMI), mean muscle attenuation (Hounsfield units) for myosteatosis, and visceral adipose tissue area (VAT). Diet quality was scored using the Revised Diet Quality Index (DQI-R). Graft function was followed with creatinine-based estimated glomerular filtration rate (eGFR) calculated by the CKD-EPI equation. Results: Mean age was 45.7 ± 13.2 years and 58% were men. The prevalence of low muscle mass was 26.0%, myosteatosis 73.5%, and visceral obesity (VAT ≥ 100 cm2) 45.6%. No participant had “good” diet quality; 48.4% had poor diet quality. DQI-R showed a weak positive correlation with SMI (r = 0.157; p = 0.047) but was not significantly related to VAT, subcutaneous adipose tissue (SAT), Kidney transplant recipient (VSR) or myosteatosis. In multivariable models, age and VAT were associated with HbA1c, whereas body composition and diet quality variables were not independent predictors of eGFR. Myosteatosis was independently associated with older age. Conclusions: Visceral adiposity and impaired muscle quality frequently clustered and were linked to metabolic status. These findings support post-transplant follow-up strategies that go beyond BMI and integrate body composition and nutritional assessment within a multidisciplinary care model.