Do traditional medicine-based diets lead to greater weight loss than modern diets in overweight and obese students? A randomized controlled trial

BACKGROUND: Obesity in adolescents is a critical health concern linked to severe adulthood conditions; therefore, this randomized controlled trial compared the relative effectiveness of a modern dietary approach versus a traditional Iranian medicine-based diet for weight management. METHODS: Following simple randomization (stratified by gender and school type), 93 junior high school students were assigned to either a modern diet (300–500 kcal/day deficit, n = 41) or a traditional Iranian diet (qualitative humoral-based, n = 52) for 90 days. Dietary adherence was assessed using a 10-point Visual Analog Scale (VAS). Baseline demographic, anthropometric, and unhealthy eating pattern data were recorded. RESULTS: Over 90 days, the modern diet group achieved a statistically significant decrease in BMI (mean change: -0.31 kg/m²; P = 0.032) and waist circumference (P < 0.001). Conversely, the traditional Iranian diet group showed a significant increase in weight and BMI (mean change: +0.74 kg/m²; P < 0.001). Between-group differences for BMI change were highly significant favoring the modern diet (P < 0.001). Dietary adherence and feasibility scores improved in the modern group (P = 0.033) but decreased in the traditional group (P = 0.001). CONCLUSIONS: These findings suggest that the modern dietary approach was more effective for weight loss in this student population, likely due to better adherence influenced by greater public knowledge and accessibility of information, alongside healthier dietary pattern shifts. TRIAL REGISTRATION: The study is registered with the Iranian Registry of Clinical Trials (IRCT20230610058442N1 dated September 10, 2023).