eTable 1. Composition of the guideline group: the participating specialty societies and associations and their delegates to the guideline-creating committee (collaborators*).

Guideline-issuing society	Representatives/experts
Surgical Working Group for the Treatment of Obesity (CAADIP) of the German Society of General and Visceral Surgery (DGAV)	Prof. Dr. med. Arne Dietrich*, Leipzig (chairman) Prof. Dr. med. Lars Fischer*, Baden-Baden Dr. med. Daniel Gärtner*, Karlsruhe PD Dr. med. Mike Laukötter*, Münster Prof. Dr. med. Beat Müller-Stich*, Heidelberg Dr. med. Martin Susewind*, Berlin Dr. med. Harald Tigges*, Landsberg am Lech PD Dr. med. Markus Utech*, Gelsenkirchen Prof. Dr. med. Stefanie Wolff*, Magdeburg
Participating specialty societies and associations	Representatives/experts
German Obesity Society (DAG)	Prof. Dr. med. A. Wirth*, Bad Rothenfelde
German Diabetes Society (DDG)	PD Dr. med. Jens Aberle*, Hamburg
German Society of Nutritional Medicine (DGEM)	Prof. Dr. med. Arved Weimann*, Leipzig
German Society of Endoscopy and Imaging Techniques (DGE-BV)	Prof. Dr. med. Georg Kähler*, Mannheim
German Society of Psychosomatic Medicine and Medical Psychotherapy (DGPM)	Prof. Dr. Martina de Zwaan*, Hanover
German Society of Plastic, Reconstructive, and Esthetic Surgeons (DGPRÄC)	Prof. Dr. med. Adrian Dragu*, Dresden
German Collegium of Psychosomatic Medicine (DKPM)	Prof. Dr. Martina de Zwaan*, Hanover
Association of Diabetes Counseling and Educating Professions in Germany (VDBD)	Prof. Dr. rer. medic. Markus Masin*, Münster
Professional Association for Ecotrophology (VDOE)	Dr. rer. nat. Tatjana Schütz*, Leipzig (coordination)
German Obesity Surgery Self-Help Association	Andreas Herdt*, Kelsterbach