Pre-operative dietary restriction for patients undergoing bariatric surgery in the UK: observational study of current practice and dietary effects.

ABSTRACT

BACKGROUND: Bariatric surgery is effective at achieving weight loss in the severely obese, with the majority of procedures performed laparoscopically. A short-term pre-operative energy restrictive diet is widely adopted to enable surgery by reducing liver size and improving liver flexibility. However, the dietary approach is not standardised. This observational study reports on pre-operative restrictive diets in use across bariatric services in the UK. METHODS: Between September and November 2012, information was collected from bariatric services on current or past pre-operative diets, and any research providing evidence for the use or modification of their diets. RESULTS: Around one third of bariatric services (28) in the UK responded, with a total of 49 diets in current use. Types of diet include low energy, low carbohydrate and liquid, with 59 % offering low energy/low carbohydrate food-based, 21 % milk/yoghurt, 18 % meal replacement (liquid) and 2 % clear liquid. Diet duration varies between 7 and 42 days. Limited anecdotal evidence was provided by services evaluating the pre-operative diet, and its alternative approaches, with dietary choice primarily clinician-led. CONCLUSIONS: This study has highlighted variability and lack of consensus in the form of pre-bariatric surgery diet used across different centres. Further research comparing outcomes for alternative diets would support best practice in the future.