Clinical Study attributes
Other attributes
Nonalcoholic Liver disease (NAFLD) is known to be caused by deposition of fat in the liver. The impact of NAFLD on bariatric surgery is of great concern. Enlarged fatty livers increase the operative complications of bariatric surgery and weight loss prior to bariatric surgery has been shown to reduce complications of surgery. Most bariatric surgery programs use a conventional low fat, calorie restricted diet during the preparation phase for surgery. The investigators will compare the effects of the low carbohydrate versus the low fat diets on weight loss, reduction in liver fat content, and liver size. These results will provide new clinical insights into the optimal dietary intervention to make bariatric surgery safe and effective for the increasing numbers of patients opting for this aggressive therapy for morbid obesity. Patients approved for bariatric surgery by the University of Michigan Bariatric Surgery multidisciplinary committee will be randomly assigned to either a 1000 to 1200 calorie low fat or low carbohydrate, 8-week study diet. All the food for this study will be provided for free by the study team. Participants will be required to meet with the study team weekly to pick up study food and for a nutritional consult. These visits will occur in the eight weeks preceding the patient's bariatric surgery procedure. During the bariatric surgery, a liver biopsy will be performed to assess the impact of the study diet on liver fat content.

