Table 1. A summary of methods.

Structured theory review – methods summary
1. Theory identification	From three data sources:
	Systematic on-line search ‘Theory Project’ list of 80 theories Contact with 40 experts (25 replied)
2. Inclusion/exclusion	Criteria and definition of terms
3. Data extraction	Including: ID number; theory name, full reference; verbatim general statements about behaviour change maintenance (direct quote) and explanations of behaviour change maintenance (interpretation); intended theoretical application; specified population and/or behaviour
4. Narrative data synthesis	(A) Testable explanations for behaviour change maintenance reviewed in included theories (B) Generation of themes: testable explanations analysed and grouped into theory themes and subthemes (C) Theory themes validated (10 health psychology researchers)
5. Review writing	Review structured around the themes; interconnections between the themes discussed