City Research Online

Portfolio of Practice

Earle, E. A. (2009). Portfolio of Practice. (Unpublished Doctoral thesis, City University London)



People with psychosis and schizophrenia consume a poorer diet than the general population. This impacts negatively on both physical and mental health. Coupled with the effects of medication, weight gain is also probable, affecting body image, self esteem and social functioning. Mental Health Services in the UK have begun to recognise the need for nutritional care. However eliciting behavioural change in service users has been a challenge. To overcome this, this study evaluates the efficacy of a unique psychological intervention for healthy eating and weight management.


Three groups of service users were compared: those receiving the Psycho-Nutritional Intervention (PNI), standard nutritional care (treatment as usual) and a control group. Outcome measures included Nutritional Knowledge, Readiness to Change, Health Locus of Control, Decisional balance items and the Body Weight, Image and Self Esteem (B-WISE) measure. Data were collected at baseline (Time 1), one month (Time 2) and three months (Time 3).


Although the PNI group did not improve outcomes to a greater extent than the other two groups, positive change over time was observed in terms of mean scores. A significant finding was that the PNI group elicited both the most positive progression in terms of readiness to change, but also the most negative regression, explaining in part, the lack of significant results, as expected.


Although effective for some, the use of psychological interventions that aim to empower and enhance internal control, may be anti-therapeutic if they elicit a negative effect on self-esteem because an individual still feels unable to change. The common assumption is that interventions will elicit either a neutral or positive effect. However this may not be the case. Accordingly, it is important to not only tailor the content of interventions, but also to the process of deciding who receives them.

Publication Type: Thesis (Doctoral)
Subjects: B Philosophy. Psychology. Religion > BF Psychology
Departments: Doctoral Theses
School of Health & Psychological Sciences > Psychology
School of Health & Psychological Sciences > School of Health & Psychological Sciences Doctoral Theses
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