Fully digital intervention, where they received the same educational materials through WhatsApp twice a week over the course of one month. The educational materials were presented through easily understandable posters, brief videos, and followed by short quizzes to reinforce the acquired knowledge. Additionally, the digital intervention incorporated the same behavior change strategies that were utilized in the hybrid group. Participants were also introduced to MyFittnessPal application in order to help them track their dietary habits and monitor their progress since it is considered a tool for self-monitoring and promoting healthy dietary behaviors throughout the intervention period.

Dietary habits were evaluated using a questionnaire adapted from research on food consumption frequencies in Qatar, which share similar characteristics with Saudi Arabia. The questionnaire assessed the frequency of consumption of various food groups, including vegetables, fruits, carbohydrates (e.g., bread, rice, pasta), proteins (e.g., chicken, beef, fish), and dairy products (e.g. yoghurt and cheese). Participants responded to questions such as, "How often do you consume fresh fruits/green leafy vegetables/fish? To evaluate dietary variety, the study employed the Healthy Plate Variety Score, calculated using a modified methodology based on Jones et al. (2015). This approach involved dichotomizing food intake from the five main groups into two categories (daily intake vs. non-daily). Foods consumed daily received a score of 1, while those not consumed daily received a score of 0 with a potential maximum score of 5.0.

Body measurements were obtained using standardized equipment following established operating procedures. Trained senior dietitians objectively assessed the height and weight of adolescents using a mechanical combined scale and a stadiometer (Detecto). Prior to measurement, a technician ensured that the equipment was properly calibrated. Height was recorded to the nearest 0.1 cm while participants were barefoot and dressed in minimal clothing. Weight was measured and documented to the nearest 0.1 kg. The Body Mass Index (BMI) was calculated by dividing the weight in kilograms by the square of the height in meters. Weight status was classified according to the criteria set by the World Health Organization (WHO): underweight was defined as a BMI of less than 18.5 kg/m², normal weight ranged from 18.5 to 24.9 kg/m², overweight was categorized as a BMI between 25.0 and 29.9 kg/m², and obesity was indicated by a BMI of 30.0 kg/m² or higher.