Effect of Bariatric Surgery on Weight Loss, Nutritional Deficiencies, Postoperative Complications and Adherence to Dietary and Lifestyle Recommendations: A retrospective cohort study from Bahrain.

OBJECTIVES: This study aimed to investigate the effect of bariatric surgery on degree of weight loss, as well as the prevalence of nutritional deficiencies, postoperative complications and adherence to dietary and lifestyle recommendations in a cohort of patients from Bahrain. METHODS: This retrospective cohort study took place between March and September 2018 at two hospitals in Bahrain. All adult patients who had undergone bariatric surgery between 2012-2017 were included. Sociodemographic and clinical information was collected from the patients' medical records and during phone interviews. RESULTS: A total of 341 patients participated in the study. The mean age was 39.82 ± 9.95 years and 67.7% were female. There was a significant relationship between postoperative body mass index and both the type of surgery and time since surgery (P = 0.025 and 0.008, respectively). While type of surgery had no significant effect on percent of excess weight loss (EWL) or percent of total weight loss (TWL), time since surgery significantly affected both of these weight loss measures (P = 0.006 and 0.001, respectively). Biochemical tests revealed haemoglobin, mean corpuscular volume, 25-hydroxy vitamin D, ferritin and iron deficiencies. Commonly reported complications included hair loss (59.5%), flatulence/abdominal pain (39.3%), dry skin (34.3%) and gastroesophageal reflux disease (33.1%). The level of adherence to dietary and lifestyle recommendations was high to moderate. CONCLUSION: Bariatric surgery was effective in accelerating EWL and TWL; however, it also resulted in complications such as nutritional deficiencies and gastrointestinal side-effects.