This study evaluates the effectiveness of a 3-month video-based lifestyle intervention, focused on promoting healthy lifestyle habits (healthy eating and increased physical activity), on adults with type 2 diabetes mellitus (DM2). Participants will be randomly allocated to receive the intervention either delivered by their own physician (experimental group) or by a physician unknown to them (control group). Assessment will include sociodemographic variables, glycated hemoglobin / HbA1c (primary outcome), body mass index, blood pressure, glycemic and lipid metabolism variables, physical activity level, adherence to the Mediterranean diet, therapeutic alliance, and health-related quality of life. The randomization process will be stratified according to HbA1c, therapeutic alliance, age, and sex.