Metabolic and bariatric surgery in vegetarians and vegans

Vegetarianism is constantly increasing worldwide. However, the role of metabolic and bariatric surgery (MBS) in vegetarians/vegans is unclear as there is very limited data on this topic. The aim of this study was to evaluate MBS outcomes in vegetarians or vegans.

Retrospective analysis of a prospectively maintained database of a single-bariatric surgeon was carried out. All patients with a vegetarian or vegan lifestyle undergoing MBS were included.

Eleven patients were included; none were lost to follow-up. Ten patients were women, the mean age and Body Mass Index (BMI) were 40.8±14 years and 43.5±4.9 kg/m², respectively. Five patients (45%) were lacto-ovo-vegetarians, one (9%) was ovo-vegetarian, two (18%) were lacto-ovo-pesco-vegetarians, and three (27%) were vegans. Eight patients consumed vitamin supplements preoperatively, the mean albumin level was 4.1±0.2, 3/11 patients had vitamin D deficiency, 2/11 patients had vitamin-B12 deficiency, and 2/11 patients had iron deficiency. Eight patients (73%) underwent one anastomosis gastric bypass (OAGB), 2/11 patients (18%) underwent single anastomosis duodeno-ileal bypass with sleeve gastrectomy, and one patient (9%) underwent sleeve gastrectomy, the mean biliopancreatic limb length in OAGB was 225 cm. The median follow-up time was 17 months, the mean BMI and percentage of total weight loss during follow-up were 28.2±5 kg/m² and 35.3±10.7%, respectively. The mean albumin level was 3.82±0.27, 3/11 patients had vitamin D deficiency, and 3/11 patients had iron deficiency.

This study reports preliminary data on MBS outcomes in vegetarian/vegan patients. It was shown to be safe, effective, and an acceptable rate of nutritional deficiencies during follow-up. Further large cohort studies are required to clarify this data.