Changes in Dietary Nutrient Intake and Estimated Glomerular Filtration Rate over a 5-Year Period in Renal Transplant Recipients

Abstract

The scarcity of dietary guidance for renal transplant recipients (RTRs) raises concerns regarding obesity and associated comorbidities, including impaired renal function. This two-stage cross-sectional study examined longitudinal changes in dietary nutrient intake in the same individuals over a 5-year interval. This study involved two stages: T1 (September 2016 to June 2018) and T2 (July 2022 to August 2023). The average duration between the two data collection stages was 6.17 ± 0.42 (range 5.20–6.87) years. The study included 227 RTRs with an average age and time since transplant of 49.97 ± 12.39 and 9.22 ± 7.91 years, respectively. Of the 35 patients who participated in both phases, fewer than half met the recommended intakes for energy, dietary fiber, and most vitamins and minerals, as set in the Dietary Reference Intakes (DRIs) or by the Dietitian Association Australia (DAA). Over half exceeded the DRI recommended intake for total protein, and more than 80% of the protein consumed per kilogram of body weight exceeded the DAA’s recommendations. In the T2 stage, the RTRs had a significantly higher blood urea nitrogen level, lower albumin level, and estimated glomerular filtration rate. These findings indicate that deteriorating dietary intake in RTRs can adversely affect their nutritional status and transplanted kidney function over a 5-year period.