Video-Based Lifestyle Counseling in Adults With Type 2 Diabetes.

Effectiveness of a Video-Based Lifestyle Intervention Delivered by Patients' Own Primary Care Physicians Versus an Unfamiliar Physician in Adults With Type 2 Diabetes Mellitus

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.

Type 2 diabetes mellitus (DM2) is a major global public health challenge associated with increased morbidity and mortality. Lifestyle modification is a cornerstone of treatment; however, long-term adherence remains limited. Digital health interventions offer scalable and accessible tools to improve self-management and behavioral change.

This prospective, multicenter, randomized controlled trial will evaluate a video-based lifestyle intervention. A total of 156 adults with DM2 under routine medical follow-up will be recruited from healthcare centers in Sagunto and Castellón (Spain) and randomly assigned (1:1) to one of two parallel groups.

The experimental group will receive the intervention through audiovisual content delivered by their own physician, while the control group will receive identical content delivered by physicians unknown to the participants. The intervention consists of structured multimedia modules focusing on nutrition, physical activity, strength exercise, and psychological strategies to support behavior change.

Assessments will be conducted at baseline and immediately after the 3 month intervention. Additional follow up assessments are planned at 6 and 12 months. The study explores how extent the physician's identity influences 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.

Inclusion Criteria:

• Adults aged 18-65 years
• Diagnosis of type 2 diabetes mellitus
• Under medical follow-up in participating centers
• Access to the internet and a smartphone
• Ability to provide informed consent

Exclusion Criteria:

• Pregnancy
• Type 1 diabetes or other specific forms of diabetes
• Severe acute or unstable medical condition
• Contraindication to diet or exercise
• Severe psychiatric disorder
• Eating disorder
• Physical disability limiting physical activity
• Participation in another structured weight-loss or lifestyle program
• No medical visit in the last 2 years