Efficacy of Transtheoretical Model on Preventive Nutritional Behaviors of Cardiovascular Diseases: A Randomized Controlled Trial

Abstract

Background and purpose: Cardiovascular diseases are the leading cause of death in Iran and today these diseases occur at younger ages. The purpose of this study was to assess the effect of educational-based health promotion interventions using the Transtheoretical Model (TTM) on nutritional behaviors (consumption of fruits, vegetables, and fish) in order to reduce the risk factors for cardiovascular disease in high-risk adults. Materials and methods: We conducted a randomized controlled trial in 1230 people aged 30-50 years. Some information including the knowledge, food intake status (fruits, vegetables and fish consumption) and intermediate risk factors such as body mass index, abdominal obesity, blood pressure, blood lipids and blood glucose were recorded. Then 332 high risk participants (intervention group= 164 and control group= 168) were selected via multistage sampling. The interventions was carried out through training classes, brochures and posters, and text messages. Intervention programs were based on individuals’ readiness for behavioral changes. Results: Significant differences were found between the intervention and control groups in knowledge and consumption of fruits and vegetables (p<0.001). But after the intervention, consumption of fish was not significantly different between the two groups (p= 0.4). There were significant differences in TTM constructs except self -efficacy (p= 0.2). Moreover, there were significant differences in biochemical factors except LDL and anthropometric indexes (p= 0.2). Conclusion: According to this study, the model-based intervention was found effective in increasing health-oriented behavior. Increasing the intake of fish requires broader interventions and changes in anthropometric indexes and LDL demands more time. (Clinical Trials Registry Number: IRCT2019010226909N1)

Keywords

• health promotion interventions
• cardiovascular diseases
• risk factors
• transtheoretical model
• nutritional behaviors