Comparison of dietary intake following laparoscopic one anastomosis gastric bypass between groups with different pre-operative body mass index

Background and Aim: One anastomosis gastric bypass (OAGB) is considered as a surgical treatment option for patients with morbid obesity. However, significant decreases in dietary intake and nutrient malabsorption after OAGB may potentially lead to nutritional deficiencies. This study was therefore conducted to assess and compare the mean values of dietary intake over 12 months following OAGB in patients with different pre-operative body mass index (BMI). Methods: The study was performed on 60 patients with morbid obesity (88.3% female) that underwent OAGB between January 2011 and November 2018. The average daily nutrient intake values were obtained from food frequency questionnaires. Other data were drawn from the National Obesity Surgery Database. Results: The mean (SD) pre-operative age, weight and BMI were 41.08 (9.41) years, 121.43 (21.01) kg, and 46.77 (6.17) kg/m2, respectively. Participants were divided into two groups based on their pre-operative BMI (1: BMI≤ 45 kg/m2, n=29; and 2: BMI 45 kg/m2, n= 31). The mean %EWL at one year postoperatively was 52.37±8.63 and 50.82±8.75 in groups 1 and 2, respectively. However, there was no significant difference in %EWL between groups (p=0.49). Additionally, the percentage of energy consumption from carbohydrates, protein and fats after surgery was 55.49±6.19%, 16.18±2.60% and 32.05±5.97%, respectively. No significant difference was observed in average daily energy and macronutrient intakes between groups (p 0.05 for all). Conclusion: Pre-operative BMI values probably had no significant effect on post-operative %EWL, nor on energy and macronutrient intake.