Schizophrenia, Nutrition and Choices in Kilojoules (SNaCK): protocol for a feasibility and acceptability randomised controlled trial of two dietary interventions.

Background: Individuals with schizophrenia experience significantly higher rates of chronic physical health conditions, driving a 20-year reduction in life expectancy. Poor diet quality is a key modifiable risk factor; however, owing to side-effects of antipsychotic medication, cognitive challenges and food insecurity, standard dietary counselling may not be sufficient for this population group.

Aim: To evaluate the feasibility, acceptability and preliminary effectiveness of two dietary interventions - pre-prepared meals and meal kits - for individuals with schizophrenia.

Method: The Schizophrenia, Nutrition and Choices in Kilojoules (SNaCK) study is a 12-week, three-arm, cross-over, randomised controlled trial. Eighteen participants aged 18-64 years diagnosed with schizophrenia or schizoaffective disorder will be recruited from community mental health services in Australia. Participants will be randomised to receive pre-prepared meals, meal kits or a supermarket voucher as a control, crossing-over at the end of weeks 4 and 8, so that all participants experience all three study arms. Primary outcomes include feasibility (recruitment rate and retention, number of days participants use pre-prepared meals or meal kits, adherence to meals as prescribed, difficulty in meal preparation and meal wastage) and acceptability (meal provision preference ranking and implementation) of the nutrition interventions. Secondary outcomes include the effects of the intervention on metabolic syndrome components, dietary intake, quality of life and food security measures.

Conclusions: Feasible, acceptable and effective dietary interventions for people with schizophrenia are urgently needed. Findings from this trial will inform future larger randomised controlled trials that have the potential to influence policy and improve health outcomes for this vulnerable population.