Not just about weight: Identifying hidden nutritional vulnerability after radical cystectomy.

Patients undergoing radical cystectomy face substantial nutritional challenges, yet dietary intake patterns and their adequacy remain poorly defined. In this prospective observational study of 25 ERAS-managed patients, energy and protein adequacy was low during the first postoperative week, while body weight remained stable - likely influenced by fluid retention. Significant weight loss emerged by day 14 (-2.3%; p < 0.001), which increased by day 30 (-5.3%; p < 0.001), despite dietetic follow-up and improvements in dietary intake. Patients requiring nasogastric decompression experienced greater weight loss than those without (-7.2% vs. -3.9%; p = 0.004), suggesting an association with nutritional deterioration. We conclude that early weight trajectory alone may not be a good indicator of nutritional status. Evaluating dietary intake, nutritional symptoms, and body composition including fluid balance is likely required for optimal clinical decision-making. This underscores the importance of individualized, symptom-responsive strategies, including consideration of supplemental nutrition in patients with persistent intolerance.