The main purpose of this project is to further explore the metabolic effects and the mechanisms underlying the improvement in glucose homeostasis following bariatric surgery. The project will involve both prevention and treatment of Type 2 Diabetes (T2D), and both pre-diabetic as well as diabetic subjects with obesity will be included. This part of the project focuses on patients with manifest T2D and they will be assigned to surgical and non-surgical intervention, respectively, in a strictly controlled and randomized manner.

Inclusion Criteria:

• Males and females aged 18-60 years
• Type 2 Diabetes Mellitus with duration of no more than 10 years, treated with 0-3 oral anti-diabetic drugs or Glucagon-like peptide-1 (GLP-1) analog.

Exclusion Criteria:

• Pregnant or planning to be pregnant during the study.
• Known or suspected history of significant drug abuse.
• History of alcohol abuse or excessive intake of alcohol as judged by investigator.
• History of severe allergy/hypersensitivity or ongoing allergy/hypersensitivity, as judged by the investigator
• Sleep apnea
• Any previous serious cardiovascular event, stroke , acute myocardial infarction.
• Diabetes complications : proliferative retinopathy, maculopathy, chronic renal failure stadium 3 with an Estimated Glomerular Filtration Rate (eGFR) <60, foot ulcers, symptomatic neuropathy
• Medications within 3 months : Insulin, Thiazolidinediones
• Any other condition with in the opinion of the investigator would render the patient unsuitable for inclusion in the study and /or for the patients safety
• Judgment by the investigator that the subject should not participate in the study if considers subject unlikely to comply with study procedures, restrictions and requirements.