Specialist in general surgery. Graduate of the Faculty of Medicine at the Jagiellonian University Collegium Medicum in Kraków. On a daily basis, he works at the Clinical Department of General, Oncological, Metabolic Surgery and SU in Krakow. In his practice he deals with patients suffering from obesity including giant obesity. He performs laparoscopic bariatric surgery and endoscopic obesity treatments, including gastric balloon therapy. Dr Malczak has authored and co-authored dozens of articles in foreign journals.