The validity of Prochaska and DiClemente's stages of change model in relation to dietary therapy
Diet plays an important role in the development of many of the major diseases in Western countries, including cardiovascular disease and various forms of cancer, and there are initiatives to change diets in many countries. The transtheoretical (stages of change) model, developed by Prochaska and DiClemente (1983), has attracted a great deal of research attention in health psychology and seeks to be applicable to all forms of health behaviour change, including dietary change. It offers a way of characterising people in terms of their readiness to change behaviour, the types of psychological variables and processes important at the different stages of change and recommendations for the types of interventions most appropriate in order to move through the stages. However, this model has mainly been used with addictive behaviours such as smoking.
This project is investigating the application of the transtheoretical model to dietary change. It has included initial cross-sectional work, which has examined how processes of change and self-efficacy differ across stages of dietary change. This initial questionnaire study was followed by semi-structured interviews in order to gain a more detailed insight into the processes associated with dietary change.
This work is being followed up with a major intervention study at Hammersmith Hospital (in collaboration with Dr Gary Frost) aiming to change fat intake in Type 2 diabetic patients. This involves comparing the impact of stage-matched interventions with a non-stage matched intervention and a control group with no intervention in order to test the efficacy of the model in changing dietary behaviour.
Richard Shepherd is an Emeritus Professor of Psychology, having retired in August 2011. He obtained degrees in Natural Sciences from Cambridge and in Psychology from Cardiff and Southampton. He was a Research Fellow at the University of Surrey and then worked at the Institute of Food Research from 1982 to 1998, initially in Norwich and then in Reading, before joining the University of Surrey as a Reader.
He has carried out research on a range of issues related to the factors influencing food choice. In particular this has involved the development and application of social cognition models to food choice issues and the exploration of the factors influencing dietary change. He has also conducted research on the perception of risk and risk communication particularly in relation to food issues. He has published widely in all of these areas of research, including editing two books.
He has directed research funded by BBSRC, ESRC, MAFF, FSA, Wellcome Trust and industry, in addition to several collaborative European projects funded by the EU. He is a Chartered Psychologist and a Fellow of the British Psychological Society. In the past Richard has been a member of the UK Food Standards Agency Social Science Research Committee, Food Standards Australia New Zealand (FSANZ) Social Science Expert Advisory Group and the ESRC Grant Assessment Panel.
Papers and book chapters
Shepherd, R. (2005). The use of the stages of change model with dietary behaviours. In R. Shepherd & M. M. Raats (Eds.), The Psychology of Food Choice. CABI.
Moore, A. & Shepherd, R. (2001). The application of the transtheoretical model to dietary behaviour. Paper presented at the British Psychological Society Annual Conference, Glasgow, 28-31 March 2001. Proceedings of the British Psychological Society, 9, 228.
Moore, A. & Shepherd, R. (2002). The application of the transtheoretical model to reducing fat intake. Paper presented at the International Society of Behavioural Nutrition and Physical Activity, Seattle, 12-13 July 2002.
Shepherd, R. & Moore, A. (2001). Application of the Transtheoretical Model to changing dietary behaviours. Paper presented at the BPS Health Psychology Conference, St Andrews, 5-8 September 2001. Proceedings of the British Psychological Society, 2003,11 (1), 42-43.
Shepherd, R. & Moore, A. Changing dietary behaviours: can the stages of change model help? Paper presented at the BPS Social Psychology Section Conference, University of Surrey, 18-20 July 2001.
Shepherd, R. & Moore, A. (2001). Changing dietary behaviours: can stage theories help? Paper presented at Promoting Public Health: A Social-Psychological Perspective, Chambery, France, 10-12 May 2001.
Shepherd, R., Moore, A., & Frost, G. (2002). Stages of change and dietary behaviours in type 2 diabetes. Paper presented at the 16th Conference of the European Health Psychology Society, Lisbon, 2-5 October 2002.
Shepherd, R., Moore, A., & Frost, G. (2003). Stages of change and dietary behaviour. Paper presented at the Society for Nutrition Education Annual Conference, Philadelphia, 26-30 July 2003.
Shepherd, R., Moore, A., & Frost, G. (2003). Transtheoretical model processes of change as predictors of dietary change. Poster presented at the International Society for Behavioral Nutrition and Physical Activity, Quebec, 17-20 July 2003.
Research groups and centres
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