Table 1 Definition of each of the measurement properties included in this review

Validity

Ability for a measure to accurately reflect the construct it is designed to measure.

Criterion validity

Output of a measure produces similar results to a ‘criterion’ measure. This includes studies that have examined a tool for determining energy expenditure with calorimetry (including doubly labelled water) used as the criterion measure.

Convergent validity

Output of a measure produces similar results to a reference measure not considered a criterion.

Face validity

Appearance of a measure, in that it appears to measure what it claims to measure

Content validity

Extent to which a measure covers all aspects of the intended domains or dimensions that it claims to measure

Reliability

Extent to which a tool gives measurements that are consistent, stable and repeatable.

Test-retest reliability

The extent to which a measure can obtain similar results in repeated trials, keeping as many conditions stable as possible

Inter/Intra Instrument Reliability

The extent to which scores are consistent when measurements are taken by different versions of the same instrument (inter-instrument) or by the same version of an instrument repeatedly (intra-instrument)

Feasibility

The extent to which a measurement tool: is suitable for the target population; can be successfully delivered in the target population/context; shows promise of being successful within the intended population. This can include: participant acceptability, researcher acceptability and cost, which can be assessed for all measurement tools through qualitative feedback of participants and through missing or lost data occurred from the measurement tool (with the exception of proxy or self-reported tools that can only be determined through qualitative means including the comprehensiveness and relevance of items).