Objective: To evaluate whether the baseline Dietary Inflammatory Index (DII®) was associated with weight loss and body composition change after bariatric surgery.
Methodology: This longitudinal study included 132 women with obesity (BMI ≥ 35 kg/m2, 43.0 ± 9.7 years), followed up for 6 months after bariatric surgery. The DII® was calculated from dietary data collected using 24-h dietary recall interviews. Anthropometric variables, socio demographic variables, health-related habits, history of disease, as well as gastrointestinal symptoms, both in the preoperative period (baseline) and 6 months after bariatric surgery were collected from the patients' medical records.
Results: Individuals with a more pro-inflammatory diet (DII > 0.35 median value) preoperatively experienced smaller weight loss (- 22.7% vs. - 25.3%, p = 0.02) and fat mass loss (- 31.9 vs. - 36.2%, p = 0.026), with no difference in lean mass (p = 0.14). In a linear regression model, the baseline DII score was negatively associated with percentage change in weight and fat mass and positively associated with weight and fat mass in the sixth month after surgery. In addition, a pro-inflammatory baseline DII score was correlated with a lower intake of fruit (r = - 0.26, p = 0.006), vegetables (r = - 0.47, p = 0.001), and legumes (r = - 0.21, p = 0.003) in the postoperative period.
Conclusion: In this longitudinal study, a pro-inflammatory diet at baseline was associated with smaller reductions in weight and body fat and poorer dietary quality (reduced consumption of fruits, vegetables, and legumes) 6 months after bariatric surgery.
Keywords: Gastric bypass; Inflammation; Obesity; Weight-loss.