Part one: Literature review - Objective: Similarities between patients and their therapist may facilitate engagement in therapy. The literature review critically appraised the evidence that sex matching between children and adolescents and their therapists influenced therapy. Method: A systematic search yielded 16 papers that were then critically appraised. Results: Findings were categorised into three areas: client preferences for a sex matched counsellor; the effects of sex matching during therapy; and the effects of sex matching on outcomes of therapy. A fairly consistent finding was that female clients preferred a female counsellor. Conclusions: Sex matching between children and adolescents and their therapist has limited predictive value in therapy process and outcome. Future research may be better focused whether on client preferences to affect treatment uptake. Part two: Research report - Introduction: Similarities between female therapists and their patients in eating disorder services may impact on the therapist. Previous research has suggested that therapists and other professionals can experience changes to their body image and eating behaviours whilst working in eating disorder services. Little is known about what sense therapist make of these changes. Method: Semi-structured interviews were completed with eight clinical psychologists. Findings were analysed using Interpretative Phenomenological Analysis approach. Results: Four super-ordinate themes emerged from the data: affirming one’s identity’; ‘close knit team’; ‘protecting oneself’; and ‘being influenced’. These related to participants professional identity and how they interpreted the changes in their body image and eating behaviours. Conclusions: Findings indicated that the participants made sense of the changes to their body image and eating behaviours in different ways. The way the changes were perceived and discussed as a team was likely to have influenced how participants felt in the working environment. Part three: Critical appraisal - The critical appraisal is a reflective account of the experiences encountered during the research process.