The proposed study is designed to investigate a novel intervention to promote behaviour change that has been shown to be effective in changing behaviour in public health (e.g. unhealthy dietary intake, unsafe sun exposure, hazardous drinking and smoking cessation) The intervention is simple to implement, requires little training of staff and may have major benefits for the patients and the NHS. The intervention is based on self-affirmation theory. Central to this body of work is the recognition that most health-risk education confronts people with information that is threatening, both to survival, and to their sense of self. The person's response is to interpret the information in a way that reduces the threat to them, for example by denigrating the veracity of the information. In turn the bias with which the information is interpreted reduces its ability to change behaviour. The theory suggests that if the person's sense of their own worth (e.g. sense-of-self) is boosted at the time of receiving the threatening health-risk message, the person is less likely to interpret the information in a biased way, rendering them more likely to accept the message, have increased intention to change and believe that they can (self efficacy), and ultimately change their behaviour. For example, Armitage examined adults' reactions to alcohol education materials, and in a randomised controlled trial compared participants who self-affirmed by completing an experimental questionnaire with participants who completed a control questionnaire. Self-affirmation not only significantly increased participants' receptiveness to the message, but also improved the effectiveness of the education in that 29% (27/92) fewer people were engaged in hazardous drinking at the end of the study if they had self-affirmed.