Predictors of preoperative weight loss achievement in adult bariatric surgery candidates while following a low-calorie diet for 4 weeks

Background Achieving program-mandated preoperative weight loss poses a challenge for many bariatric surgery candidates. No systematic method exists to identify at-risk patients early in preoperative care. Objectives This study sought to explore predictors of preoperative weight loss achievement and to develop a treatment algorithm for guiding clinical decision-making. Setting Greenville Health System, South Carolina. Methods A retrospective chart review was conducted for 378 patients who followed a program-mandated low-calorie diet (LCD) for 4 weeks to achieve≥8% excess weight loss (EWL). Associations between weight loss achievement and patient demographic, nutrition, psychological, clinical, anthropometric, and treatment characteristics documented at 5 preoperative evaluation events were analyzed using logistic regression. Results During the LCD, 62.7% of patients achieved≥8% EWL. Independent predictors of achievement (all P<.05) were male sex (OR 2.31, 95% CI 1.21–4.42), Caucasian race (OR 2.45, 95% CI 1.38–4.34), body mass index (BMI) at surgeon evaluation (50.0–59.9 kg/m²: OR.44, 95% CI.20–.97;≥60 kg/m²: OR.15, 95% CI.05–.42), number of co-morbidities (OR.83, 95% CI.74–.93), hypertension diagnosis (OR 2.42, 95% CI 1.42–4.13), prediet weight change (OR 1.08, 95% CI 1.01–1.16), and time between surgeon evaluation and preoperative LCD initiation (61–90 d: OR.46, 95% CI.23–.93). Conclusion Patients of female sex or non-Caucasian race; with a BMI≥50 kg/m², many co-morbidities, or no hypertension diagnosis at surgeon evaluation; who demonstrate prediet weight loss or extended wait time between surgeon evaluation and preoperative LCD initiation may be at risk for preoperative weight loss failure and may require preemptive diet modification to improve outcomes.