Variation and outcomes of liver-reducing dietary regimens before bariatric surgery: a national retrospective cohort study
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Published on: June 11, 2012
Sally Abbott1, Charlotte Price2, Dimitrios J Pournaras3
1Specialist Weight Management Service, University Hospitals Coventry and Warwickshire NHS Trust, Coventry, United Kingdom; Research Centre for Intelligent Healthcare, Coventry University, Coventry, United Kingdom.
Background:
Liver-reducing diets (LRDs) are mandated prior to bariatric surgery, but there are no guidelines on their implementation.
Objective:
To establish the variation and effectiveness of LRDs utilized in clinical practice.
Setting:
A nationwide, multicenter, retrospective cohort study.
Methods:
A total of 1699 adult patients across 14 bariatric centers in the United Kingdom were included. Multilevel logistic regression models were developed to examine factors predictive of 5% weight loss.
Results:
Most centers (n = 9) prescribed an 800- to 1000-kcal diet, but the duration and formulation of diet was variable. Overall, 30.6% (n = 510) of patients achieved 5% weight loss during the LRD. After adjustment for preoperative weight, women had reduced odds (odds ratio [OR], .65; 95% confidence interval [CI], .48-.88; P = .005), while increasing age (OR, 1.01; 95% CI, 1.00-1.02; P = .043) and having type 2 diabetes (OR, 1.49; 95% CI, 1.16-1.92; P = .002) increased odds of 5% weight loss. A normal consistency food LRD (OR, .64; 95% CI, .42-.98; P = .041) and energy prescription of >1200 kcals/d (OR, .33; 95% CI, .13-.83; P = .019) reduced odds, while an LRD with a duration of 3 weeks (OR, 2.28; 95% CI, 1.02-5.09; P = .044) or greater increased odds of 5% weight loss.
Conclusions:
There is wide variation in how LRDs are delivered in clinical practice, highlighting the need for an evidence-based consensus. Our findings suggest the optimal LRD before bariatric surgery contains 800 to 1200 kcals/d over a duration of 3 to 4 weeks. Further research is required to determine the optimal formulation of LRD and whether women may require a lower-energy LRD than men.
