We performed multiparametric 3D MR Elastography (MRE) in 37 obese patients who underwent bariatric surgeries. MRI/MRE, anthropometrics, and liver biopsy were obtained within three months of bariatric surgery and one year later. 12/37 (32%) patients have biopsy-proven non-alcoholic fatty liver disease (NAFLD) at the time of surgery. The MRE-assessed shear stiffness (SS) and loss modulus (LM) of subcutaneous adipose tissue decreased significantly after the surgery, as well as the liver tissue. MRE-assessed SS and LM have potential in distinguishing the obesity-induced metabolic disorder in the adipose tissues. The mechanical change may correlate with the therapeutic response in these obese patients.