Effective techniques in healthy eating and physical activity interventions: a meta-regression.
OBJECTIVE
Meta-analyses of behavior change (BC) interventions typically find large heterogeneity in effectiveness and small effects. This study aimed to assess the effectiveness of active BC interventions designed to promote physical activity and healthy eating and investigate whether theoretically specified BC techniques improve outcome.


METHODS
Interventions, evaluated in experimental or quasi-experimental studies, using behavioral and/or cognitive techniques to increase physical activity and healthy eating in adults, were systematically reviewed. Intervention content was reliably classified into 26 BC techniques and the effects of individual techniques, and of a theoretically derived combination of self-regulation techniques, were assessed using meta-regression.


METHODS
Valid outcomes of physical activity and healthy eating.


RESULTS
The 122 evaluations (N = 44,747) produced an overall pooled effect size of 0.31 (95% confidence interval = 0.26 to 0.36, I(2) = 69%). The technique, "self-monitoring," explained the greatest amount of among-study heterogeneity (13%). Interventions that combined self-monitoring with at least one other technique derived from control theory were significantly more effective than the other interventions (0.42 vs. 0.26).


CONCLUSIONS
Classifying interventions according to component techniques and theoretically derived technique combinations and conducting meta-regression enabled identification of effective components of interventions designed to increase physical activity and healthy eating.
Michie
Susan
S
Centre for Outcomes Research and Effectiveness, University College London, UK. s.michie@ucl.ac.uk
Abraham
Charles
C
Whittington
Craig
C
McAteer
John
J
Gupta
Sunjai
S
D015444:Exercise; D005247:Feeding Behavior; D005260:Female; D015438:Health Behavior; D006293:Health Promotion; D006801:Humans; D008297:Male