Introduction: We noted temporary increases in creatinine levels among kidney recipients following three traditional holidays in Taiwan. This retrospective cohort study aimed to examine the variations in eGFR levels after Chinese New Year, Dragon Boat Festival, and Mid-Autumn Festival, all linked to diets high in calories and fat. 
Method: We conducted a retrospective analysis of 364 kidney recipients with stable graft function who were following at Chang Gung Memorial Hospital Linkou from 2018 to 2022. The graft function before and after the festival was determined by calculating the eGFR level using the serum creatinine measured during clinic visits prior to and following the festival. The patients were then categorized into subgroups based on their gender, BMI, and co-morbidities. The eGFR levels before and after the festival were evaluated and compared within these subgroups. A multivariable analysis was employed to examine potential risk factors, including age, gender, BMI, and co-morbidities, and eGFR variance before the holidays, which may influence the decline in kidney function following the holiday period. 
Results: In total, 301 kidney recipients were ultimately enrolled in this retrospective cohort study. The analysis revealed a notable decrease in overall eGFR levels following Chinese New Year (from 55.23±24.36 to 54.02±24.46, p<0.001), Dragon Boat Festival (from 55.20±23.91 to 52.83±23.72, p<0.001), and the Mid-Autumn Festival (from 54.55±23.66 to 53.89±24.18, p<0.001). Tracking eGFR for three months post-holidays indicated a gradual return to baseline levels. Subgroup analysis suggested a propensity for renal function decline after all three traditional holidays among patients with diabetes mellitus, hypertension, or non-overweight. Multivariable analysis highlighted an increased variance in eGFR before the holidays as a significant risk factor for post-holiday declines.

 
Conclusion: This study noted a significant yet temporary decrease in renal function among kidney recipients after traditional holidays in Taiwan, especially evident among recipients with hypertension or diabetes mellitus, or those within normal weight ranges. Furthermore, increased fluctuations in eGFR over the preceding year elevate the probability of notable declines post-holidays.