Table 1.

Self-report measures evaluated as potential secondary outcomes

Self-report measures	Measure characteristics
aSocio-demographic questions	Age, gender, years of education
aTreatment Self-Regulation Questionnaire[26]	12 items comprising three validated sub-scales assessing three dimensions of motivation to use the POWeR intervention (Controlled-External, Controlled-Introjection and Autonomous-Identification + Integration)
Food Frequency Questionnaire	Participants report how often they eat 40 food types in a typical day and week. Developed from a validated measure [27].
Godin Leisure Time Physical Activity Questionnaire[28]	4 items assessing time spent on mild, moderate and strenuous activities during the past week
EQ-5D (Euroqol)[29]	5 items assessing general health-related quality of life, used to generate Quality Adjusted Life Years for cost-effectiveness analyses.
Theory of Planned Behaviour questions	10 items, comprising 2 items assessing each of the Theory of Planned Behaviour [30] constructs (attitude, subjective norms, perceived behavioural control, and intention) completed twice to assess attitudes relating to using the POWeR eating plan and the POWeR physical activity plan
bTherapist perceptions scale[31]	5 items assessing perceptions of the nurse support provider
cEating plan acceptability	7 items asking about the acceptability of the eating plan in terms of satiety, taste, cost and difficulty preparing or obtaining foods
cPETS Adherence Questionnaire[32]	14 items assessing socially acceptable reasons for non-adherence, followed by 3 items asking how much of the time participants had followed the low calorie eating plan, the low carbohydrate eating plan and the physical activity plan
dOther weight loss support	8 items asking about use of other interventions during the past year
dPatient Enablement Instrument[33]	6 items assessing perceived ability to cope with weight problem and general health as a result of health care in the past year.

^abaseline only; ^b6 month follow-up only; ^c6 and 12 month follow-up; ^d12 month follow-up only.