Table 1 Inclusion and exclusion criteria for STEPWISE feasibility pilot

Inclusion criteria

1) Age ≥ 18 years old. There is no upper age limit.

2) Clinical diagnosis of schizophrenia or schizoaffective disorder (defined by ICD-10 codes F20 and F25) or first episode psychosis using case note review. There is no limit on the duration of illness for those with schizophrenia or schizoaffective disorder, but first episode psychosis is defined as less than 3 years since presentation to the mental health team

3) Patients being treated with an antipsychotic. For those with established schizophrenia or schizoaffective disorder, the treatment duration should be at least 1 month prior to entry in to the trial.

4) Ability to give written informed consent

5) Ability and willingness to attend and participate in a group education programme

6) Ability to speak and read English

7) Body mass index ≥ 25 kg/m² or concerned about weight. For patients from South Asian and Chinese backgrounds, the BMI threshold is reduced to ≥ 23 kg/m².

Exclusion criteria

1) Physical illnesses that could seriously reduce their life expectancy or ability to participate in the trial

2) A co-existing physical health problem that would, in the opinion of the PI, independently impact on metabolic measures.

3) Mental illnesses that could seriously reduce their ability to participant in the trial

4) Current pregnancy, plus mothers less than 6 months post-partum.

5) Conditions associated with significant weight gain, e.g., Cushing’s syndrome

6) Significant alcohol or substance misuse which, in the opinion of the PI, would limit the patient’s ability to participate in the trial.

7) A diagnosis or tentative diagnosis of psychotic depression or mania

8) A primary diagnosis of learning disability

9) Currently (or within past three months) engaged in a systematic weight management programme.