The Relationship Between Energy Intake and Weight Loss in Bariatric Patients

Introduction: There is a huge variation in weight loss outcomes between bariatric patients, possibly due to differences in caloric intake and changes in the amount physical activity. However, the association between the change in energy intake and weight loss has not yet been the subject of an extensive investigation. Objective: To explore the relationship between total energy intake and % total body weight loss (%TBWL) over a period of 4 years post-surgery. Methods: Of the 466 patients who were asked to participate, a total 135 patients were included in this study. They all underwent bariatric surgery, 54 with primary Roux-en-Y Gastric Bypass, 43 redo Roux-en-Y gastric bypass after laparoscopic gastric banding and 38 laparoscopic sleeve gastrectomy. Pre- and post-operative dietary intake and physical activity were collected for both a weekday and a weekend day. The main analysis was performed using multiple regression analyses and was adjusted for age at surgery, BMI at baseline, obstructive sleep apnoea syndrome, type of eating behaviour, change in physical activity and protein intake (g/kg body weight). Results: %TBWL over time, post-operative energy intake and change in physical activity did not differ between the different procedure groups (p = 0.312, p = 0.988 and p = 0.050, respectively). Change in energy intake did differ between different procedure groups (p = 0.031) and linear regression showed that this was related to total body weight loss for the fully adjusted model (β = − 0.004, p = 0.014). Conclusion: This study showed a higher decrease in energy intake to be related with a higher %TBWL.