Planning and self-efficacy can increase fruit and vegetable consumption: a randomized controlled trial
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Fruit and vegetable consumption represents a nutritional goal to prevent obesity and chronic illness. To change dietary behaviors, people must be motivated to do so, and they must translate their motivation into actual behavior. The present experiment aims at the psychological mechanisms that support such changes, with a particular focus on dietary self-efficacy and planning skills. A randomized controlled trial compared a theory-based psychological intervention with a health education session in 114 participants. Dependent variables were fruit and vegetable consumption, intention to consume more fruit and vegetables, planning to consume more, and dietary self-efficacy, assessed before the intervention, 1 week afterwards, and at 6-week follow up. Significant group by time interactions for all four dependent variables documented superior treatment effects for the psychological intervention group, with substantially higher scores at posttest and follow-up for the experimental group, although all students benefited from participation. To identify the contribution of the main intervention ingredients (self-efficacy and planning), regression analyses yielded mediator effects for these two factors. A social-cognitive intervention to improve fruit and vegetable consumption was superior to a knowledge-based education session. Self-efficacy and planning seem to play a major role in the mechanisms that facilitate dietary changes.
KeywordsFruit and vegetable consumption Self-efficacy Intentions Planning Dietary changes
- Bandura, A. (1997). Self-efficacy: The exercise of control. New York: Freeman.Google Scholar
- Franko, D. L., Cousineau, T. M., Trant, M., Green, T. C., Rancourt, D., Thompson, D., et al. (2008). Motivation, self-efficacy, physical activity and nutrition in college students: Randomized controlled trial of an internet-based education program. Preventive Medicine, 47, 369–377.PubMedCrossRefGoogle Scholar
- Gutiérrez-Doña, B., Lippke, S., Renner, B., Kwon, S., & Schwarzer, R. (2009). How self-efficacy and planning predict dietary behaviors in Costa Rican and South Korean women: A moderated mediation analysis. Applied Psychology: Health & Well-Being, 1, 91–104. doi: 10.1111/j.1758-0854.2009.01004.x CrossRefGoogle Scholar
- Health Information System Development Office (HISO). (2006). Health status report of Thailand (in Thai). Nonthaburi, Thailand: Thai Health Promotion Foundation.Google Scholar
- MacKinnon, D. (2008). Statistical mediation analysis. New York: Erlbaum.Google Scholar
- Ministry of Public Health (MOPH). (2000a). Health behaviors and physical activity practices among employees within the Ministry of Public Health (in Thai). Nonthaburi, Thailand: Physical Activity Division, Ministry of Public Health.Google Scholar
- Ministry of Public Health (MOPH). (2000b). Nutrition flag manual (in Thai). Nonthaburi, Thailand: Department of Health, Ministry of Public Health.Google Scholar
- Preacher, K. J. & Hayes, A. F. (2008). Asymptotic and resampling strategies for assessing and comparing indirect effects in multiple mediator models. Behavior Research Methods, 40(3), 879–891.Google Scholar
- Reuter, T., Ziegelmann, J. P., Wiedemann, A. U., & Lippke, S. (2008). Dietary planning as a mediator of the intention-behavior relation: An experimental-causal-chain design. Applied Psychology. Special Issue: Health and Well-Being, 57, 194–207.Google Scholar
- Satheannoppakao, W., Aekplakorn, W., & Pradipasen, M. (2009). Fruit and vegetable consumption and its recommended intake associated with sociodemographic factors: Thailand National Health Examination Survey III. Public Health Nutrition, 12(11):2192–2198.Google Scholar
- Schwarzer, R., Lippke, S., & Luszczynska, A. (2011). Mechanisms of health behavior change in persons with chronic illness or disability: The health action process approach (HAPA). Rehabilitation Psychology. doi: 10.1037/a0024509.
- Wiedemann, A. U., Lippke, S., Reuter, T., Ziegelmann, J. P., & Schüz, B. (2011). The more the better? The number of plans predicts health behaviour change. Applied Psychology: Health and Well-Being, 3, 87–106. doi: 10.1111/j.1758-0854.2010.01042.x
- Wiedemann, A. U., Lippke, S., & Schwarzer, R. (2011). Multiple plans and memory performance: Results of a randomized controlled trial targeting fruit and vegetable intake. Journal of Behavioral Medicine. Published online 25 June 2011. doi: 10.1007/s10865-011-9364-2
- World Health Organization (WHO). (2003). Diet, nutrition and the prevention of chronic diseases (Report of a Joint WHO/FAO Expert Consultation. WHO Technical Report Series No. 916). Retrieved from https://www.who.int/dietphysicalactivity/publications/trs916/en/gsfao_introduction.pdf.