Zahra Shafaeian - Department of Health Education and Health Promotion, School of Public Health, Iran University of Medical Sciences, Tehran, Iran.
Tahereh Dehdari - Department of Health Education and Health Promotion, School of Public Health, Iran University of Medical Sciences, Tehran, Iran.
Mahnaz Solhi - Department of Health Education and Health Promotion, School of Public Health, Iran University of Medical Sciences, Tehran, Iran.
Fatamehsadat Amiri - Department of Nutrition, School of Public Health, Iran University of Medical Sciences, Tehran, Iran.
Namamali Azadi - Department of Biostatistics, School of Public Health, Iran University of Medical Sciences, Tehran, Iran.

Background:Adopting a healthy life style in children may protect them against osteoporosis in later life. This study was done to determine the effectiveness of gain-framed versus loss-framed using mobile phones short-messages service (SMS) intervention in promoting knowledge, attitude and preventive nutrition behaviors of osteoporosis among a sample of Iranian female students. Materials and Methods:In this quasi-experimental study, ۳۴۵ female students in Semnan, Iran were randomly selected and assigned to either intervention group ۱ (receiving gain-framed text messages, n=۱۱۵), intervention group ۲ (receiving loss-framed text messages, n=۱۱۵), and control group (no receiving text messages, n=۱۱۵). Knowledge, attitude and dietary behaviors related to osteoporosis prevention were collected by a researcher-made questionnaire before and one month after the delivery of the framed information via SMS. Seventy two short messages that emphasized the benefits of adopting the behavior (n=۳۵), and the costs of non adopting it (n=۳۵) have been sent to the participants’ phones in intervention group ۱ and ۲, respectively during the ۳۵-day intervention period. Results: The age of participants in the three groups was ۱۲ years. They were studying in the seventh grade. After the intervention, the mean scores of knowledge (۲.۳۲±۰.۶۰, p <۰.۰۰۱), attitude (۱.۵۲±۰.۶۰, p=۰.۰۳), and adopting the preventive nutrition behaviors of osteoporosis (۱.۳۰±۰.۵۸, p=۰.۰۵) variables in the intervention group ۱ had a significant increase compared to the intervention group ۲. Conclusion: The results of the study showed that gain-framed text messages significantly improved adopting osteoporosis preventive nutrition behaviors than loss framed text messages.