What Are the Most Effective Behavioural Strategies in Changing Postpartum Women’s Physical Activity and Healthy Eating Behaviours? A Systematic Review and Meta-Analysis

Successful implementation of postpartum lifestyle interventions first requires the identification of effective core components, such as strategies for behavioural change. This systematic review and meta-analysis aimed to describe the associations between behavioural strategies and changes in weight, diet, and physical activity in postpartum women. Databases MEDLINE, CINAHL, EMBASE, and PsycINFO were searched for randomised controlled trials of lifestyle interventions in postpartum women (within 2 years post-delivery). Strategies were categorised according to the Behaviour Change Technique Taxonomy (v1). Forty-six articles were included (n = 3905 women, age 23–36 years). Meta-analysis showed that postpartum lifestyle interventions significantly improved weight (mean difference −2.46 kg, 95%CI −3.65 to −1.27) and physical activity (standardised mean difference 0.61, 95%CI 0.20 to 1.02) but not in energy intake. No individual strategy was significantly associated with weight or physical activity outcomes. On meta-regression, strategies such as problem solving (β = −1.74, P = 0.045), goal setting of outcome (β = −1.91, P = 0.046), reviewing outcome goal (β = −3.94, P = 0.007), feedback on behaviour (β = −2.81, P = 0.002), self-monitoring of behaviour (β = −3.20, P = 0.003), behavioural substitution (β = −3.20, P = 0.003), and credible source (β = −1.72, P = 0.033) were associated with greater reduction in energy intake. Behavioural strategies relating to self-regulation are associated with greater reduction in energy intake.


Rationale
3 Describe the rationale for the review in the context of what is already known.

3-4
Objectives 4 Provide an explicit statement of questions being addressed with reference to participants, interventions, comparisons, outcomes, and study design (PICOS). 4

Protocol and registration 5
Indicate if a review protocol exists and if and where it can be accessed (e.g., Web address), and if available, provide registration information including registration number. 4 Eligibility criteria 6 Specify study characteristics (e.g., PICOS and length of followup), and report characteristics (e.g., years considered, language, and publication status) used as criteria for eligibility, giving rationale.

5; Additional Files
Information sources 7 Describe all information sources (e.g., databases with dates of coverage and contact with study authors to identify additional studies) in the search and date last searched. 4-5 Search 8 Present full electronic search strategy for at least one database, including any limits used, such that it could be repeated. Additional Files Study selection 9 State the process for selecting studies (i.e., screening, eligibility, included in systematic review, and, if applicable, included in the meta-analysis). 5 Data collection process 10 Describe method of data extraction from reports (e.g., piloted forms and independently, in duplicate) and any processes for obtaining and confirming data from investigators. 5-6 Data items 11 List and define all variables for which data were sought (e.g., PICOS and funding sources) and any assumptions and simplifications made.

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Risk of bias in individual studies 12 Describe methods used for assessing risk of bias of individual studies (including specification of whether this was done at the study or outcome level) and how this information is to be used in any data synthesis. 6 Summary measures 13 State the principal summary measures (e.g., risk ratio and difference in means). 6 Synthesis of results 14 Describe the methods of handling data and combining results of studies, if done, including measures of consistency (e.g., I 2 ) for each meta-analysis. 6 Section/topic # Checklist item Reported on page #

Risk of bias across studies 15
Specify any assessment of risk of bias that may affect the cumulative evidence (e.g., publication bias and selective reporting within studies). 6 Additional analyses 16 Describe methods of additional analyses (e.g., sensitivity or subgroup analyses and meta-regression), if done, indicating which were prespecified. 6

Study selection 17
Give numbers of studies screened, assessed for eligibility, and included in the review, with reasons for exclusions at each stage, ideally with a flow diagram. 7; Figure 1 Study characteristics 18 For each study, present characteristics for which data were extracted (e.g., study size, PICOS, and followup period), and provide the citations. 7; Table 1 Risk of bias within studies 19 Present data on risk of bias of each study and, if available, any outcome level assessment (see item 12).
7-8; Figure 2, Additional Files Results of individual studies 20 For all outcomes considered (benefits or harms), presen, for each study (a) simple summary data for each intervention group and (b) effect estimates and confidence intervals, ideally with a forest plot.

Additional Files
Synthesis of results 21 Present results of each meta-analysis done, including confidence intervals and measures of consistency.

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Risk of bias across studies 22 Present results of any assessment of risk of bias across studies (see item 15).

7; Additional Files
Additional analysis 23 Give results of additional analyses, if done (e.g., sensitivity or subgroup analyses and meta-regression (see item 16)).

Summary of evidence 24
Summarize the main findings including the strength of evidence for each main outcome; consider their relevance to key groups (e.g., healthcare providers, users, and policy makers). 9 Limitations 25 Discuss limitations at the study and outcome levels (e.g., risk of bias) and at the review level (e.g., incomplete retrieval of identified research, reporting bias).

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Conclusions 26 Provide a general interpretation of the results in the context of other evidence and implications for future research. 12

Inclusion criteria
Postpartum women (2 years post delivery). Editorial, narrative review, conference abstract, letters, commentaries, uncontrolled trials, study protocol, and non-randomized controlled trials; studies with pregnant women will only be included if subgroup data is available for postpartum women    78 0 β = regression coefficient, CI = confidence interval; k = number of evaluations; adjusted R 2 = adjusted proportion of heterogeneity accounted for by moderator Figure S1: Forest plots and funnel plots for weight, energy intake, and physical activity.