Clinical changes and daily life adaptations after Roux-en-Y gastric bypass: Integrating quantitative outcomes and patient-reported perspectives

Roux-en-Y gastric bypass (RYGB) is one of the most effective treatments for severe obesity, producing rapid anthropometric and metabolic improvements in the first postoperative months. However, fewer studies examine how patients interpret these early changes in daily life. This study assessed clinical outcomes and patient experiences during the rapid weight-loss phase following RYGB. Using a sequential mixed-methods design, quantitative data from 37 patients were collected approximately 1-2 months before surgery (T0) and 6-7 months after surgery (T1), including anthropometric and biochemical indicators. T0–T1 comparisons were conducted using paired t-tests or Wilcoxon tests. In the qualitative phase, a subsample of 11 participants from the quantitative sample underwent in-depth semi-structured interviews analyzed through inductive thematic analysis. Findings were integrated to identify convergence and complementarity between clinical outcomes and patients’ interpretations. Quantitatively, patients showed significant reductions in BMI, fat mass, fat-free mass, total cholesterol, LDL-cholesterol, triglycerides, and fasting glucose (p < 0.05). Qualitatively, participants interpreted these changes through lived improvements in physical functioning, autonomy, and quality of life, describing greater energy, easier mobility, better sleep, reduced pain, and the possibility of resuming daily activities. Some also perceived reduced medication used for hypertension and diabetes as a sign of improved health. Adaptive challenges, including hair loss, food intolerance, and discomfort with specific food consistencies, were generally perceived as manageable when weighed against health gains. Integration showed that early clinical changes were experienced as meaningful improvements in well-being, body confidence, and daily functioning, highlighting the importance of structured postoperative support during rapid weight loss.