The Efficacy of Energy-Restricted Diets in Achieving Preoperative Weight Loss for bariatric Pateints: A Systematic Review

The final publication is available at Springer via https://doi.org/10.1007/s11695-018-3451-1In bariatric practice, a preoperative weight loss of at least 5% is recommended. However, the hypocaloric diets prescribed vary and no consensus exists. This study examined the efficacy of preoperative diets in achieving 5% weight loss. From a systematic literature search, eight randomised controlled trials (n = 862) were identified. Half of the trials used a Bvery-low-calorie diet^ whilst the rest employed a Blow-calorie diet^. Only five diets achieved ≥ 5% weight loss over varying durations and energy intakes. By inference, compliance with a 700–1050 kcal (2929–4393 kJ) diet, consisting of moderate carbohydrate, high protein and low/moderate fat, for 3 weeks is likely to achieve 5% weight loss. A low-carbohydrate diet (< 20 g/day) may achieve this target within a shorter duration. Additional research is required to validate these conclusions

Commercial Very Low Energy Meal Replacements for Preoperative Weight Loss in Obese Patients: a Systematic Review

Background: This systematic review assessed feasibility and effectiveness of preoperative meal replacements to improve surgical outcomes for obese patients. Methods: PRISMA guidelines were followed and electronic databases searched for articles between January 1990 and March 2015. Results: Fifteen studies (942 participants including 351 controls) were included, 13 studies (n = 750) in bariatric patients. Adverse effects and dropout rates were minimal. Ten out of 14 studies achieved 5–10 % total weight loss. Six of six studies reporting liver volume achieved 10 % reduction. Endpoints for perioperative risks and outcomes were too varied to support definitive risk benefit. Conclusions: Commercial meal replacements are feasible, have minimal side effects and facilitate weight loss and liver shrinkage in free-living obese patients awaiting elective surgery. A reduction in surgical risk is unclear.Griffith Health, School of Allied Health SciencesNo Full Tex