Inclusion Criteria:  Listed for RYCG or SG at the royal derby hospital BMI>/=18 Type 2 diabetes Ability to give informed consent  Exclusion Criteria:  If they are not suitable for either RYGB or SG as determined by the MDT meeting BMI>60 Liver cirrhosis. Participants will be excluded if they are deemed unfit for an MRI via the standard safety screening form. Participants will be excluded if their waist circumference is too large for them to safely fit inside the bore of the MRI with surface coils added. Participation in other research projects