Keshishian 2005.

Methods	Non‐randomised study. Type of study: retrospective cohort. Inclusion criteria: morbid obesity. Exclusion criteria: history or evidence of liver disease other than NAFLD.
Participants	Sample size: 78 obese patients. Characteristics of included patients: average age 43.5y, female 72%, mean BMI 50.5 kg/m2.
Interventions	Duodenal switch operation and second liver biopsy during intra‐abdominal operation for various indications.
Outcomes	Histology Significant improvement of hepatic steatosis and NASH grade. Biochemical No significant reduction on liver function tests.
Notes	Follow‐up: 36 months