Inflammatory and Dietary Drivers of Super-Morbid Obesity: The Role of Neutrophil-to-Lymphocyte Ratio in Stratifying Bariatric Surgery Candidates

Background: Severe obesity, clinically defined as a Body Mass Index (BMI) ≥ 40 kg/m² or ≥ 35 kg/m² in the presence of weight-related comorbidities, is a major catalyst for non-communicable diseases, including type 2 diabetes and cardiovascular pathology. This condition is characterized by chronic, low-grade systemic inflammation (meta-inflammation) triggered by visceral adiposity and ectopic lipid deposition. While haematological indices such as the neutrophil-to-lymphocyte ratio (NLR) have emerged as robust surrogate markers of systemic inflammation, their clinical utility in bariatric risk stratification remains underutilized in the Malaysian context. This study aimed to investigate the associations between sociodemographic, clinical, nutritional, and biochemical factors with BMI among morbidly obese patients during their initial presentation at a national bariatric centre. Methods: A retrospective cross-sectional analysis was conducted on 219 patient records (2022–2024) at Institut Kanser Negara. Data regarding sociodemographic characteristics, comorbidities, dietary intake, body composition (via bioelectrical impedance analysis), and haematological profiles were reviewed. Statistical significance was evaluated using Chi-square tests and Pearson or Spearman correlation coefficients. Results: The cohort was predominantly female (65.3%) and Malay (85.8%). Significant associations were found between BMI category and gender (p=0.019), hypertension (p=0.048), and childhood obesity (p=0.027). Positive correlations were observed between BMI and energy intake (r=0.208, p=0.002), protein intake (r=0.198, p=0.003), and fat mass (r=0.916, p<0.001). Notably, the Neutrophil-to-Lymphocyte Ratio (NLR) showed a strong positive correlation with BMI (r=0.428, p<0.001), highlighting a progressive inflammatory burden associated with increased adiposity. Conclusion: These findings emphasize the necessity of integrating systemic inflammatory profiling and body composition analysis into preoperative protocols. The correlation between NLR and BMI suggests that NLR is a viable, cost-effective biomarker for identifying high-risk candidates. Implementing targeted, multidisciplinary nutritional and biochemical interventions prior to surgery is essential to optimize metabolic health and improve postoperative outcomes.