Type 2 diabetes requires active self-management from the time of diagnosis, but participation in traditional face-to-face diabetes self-management education is often limited by access-related and personal barriers. Online education may provide a more flexible and accessible way to deliver structured diabetes education, particularly for newly diagnosed adults who need timely support in understanding and managing their condition.

This study evaluated the effects of online diabetes self-management education compared with traditional face-to-face education on diabetes knowledge retention, body mass index (BMI), and HbA1c in adults newly diagnosed with type 2 diabetes who were not receiving antidiabetic medication. A total of 123 participants were included: 49 participants received online diabetes self-management education, 52 participants received traditional face-to-face education, and 22 participants who declined education formed a non-randomized control group. Diabetes knowledge was assessed at baseline, immediately after the intervention, and at three-month follow-up, while BMI and HbA1c were measured at baseline and follow-up.

At three-month follow-up, both online and traditional education groups showed significantly greater diabetes knowledge compared with the control group. The online education group also showed better immediate post-intervention knowledge than the traditional education group. Both education groups had significant reductions in BMI from baseline to follow-up, while no significant short-term effect on HbA1c was observed.

Inclusion Criteria:

• Adults aged 18 years or older.
• Diagnosis of type 2 diabetes mellitus within the previous 1 month.
• Ability to access and use information and communication technology devices (smartphone, computer, or tablet).
• Proficiency in the language used for the educational intervention.
• Ability and willingness to provide written informed consent.

Exclusion Criteria:

• Pregnancy.
• Current treatment of type 2 diabetes mellitus with antidiabetic medication (oral agents, injectable medications, or insulin).
• Previous participation in a diabetes self-management education program.
• Presence of concomitant diseases or treatments that could affect blood glucose levels (e.g., cancer or corticosteroid treatment).
• Visual impairment, cognitive impairment, literacy difficulties, or manual dexterity limitations that could interfere with participation.
• Development of any exclusion criterion during the study period.
• Deterioration in health status or occurrence of events that, in the opinion of the investigators, warranted discontinuation from the study.

Anonymized individual participant data that underlie the results reported in this study will be shared if required by the journal in which the study is published. Available data include demographic characteristics, Diabetes Knowledge Questionnaire (DKQ24) scores, body mass index (BMI), and glycated hemoglobin (HbA1c) measurements collected during the study.

Data will be available following publication of the study.

Data may be provided to qualified researchers upon reasonable request and in accordance with journal, ethical, and institutional data-sharing requirements.