Objective Promoting adherence to healthy dietary patterns is a critical public health issue. Models of behaviour, such as the Theory of Planned Behaviour (TPB) allow programme designers to identify antecedents of dietary patterns and design effective interventions. The primary aim of this study was to examine the association between TPB variables and dietary patterns. Methods A systematic literature search was conducted to identify relevant studies. Random-effects meta-analysis was used to calculate average correlations. Meta-regression was used to test the impact of moderator variables. Results In total, 22 reports met the inclusion criteria. Attitudes had the strongest association with intention (r+ = 0.61) followed by perceived behavioural control (PBC, r+ = 0.46) and subjective norm (r+ = 0.35). The association between intention and behaviour was r+ = 0.47, and between PBC and behaviour r+ = 0.32. Moderator analyses revealed that younger participants had stronger PBC-behaviour associations than older participants had, and studies recording participants' perceptions of behaviour reported significantly higher intention-behaviour associations than did those using less subjective measures. Conclusions TPB variables were found to have medium to large associations with both intention and behaviour that were robust to the influence of key moderators. Recommendations for future research include further examination of the moderation of TPB variables by age and gender and the use of more valid measures of eating behaviour. AbstractPromoting adherence to healthy dietary patterns is a critical public health issue. Models of behavior, such as the Theory of Planned Behavior (TPB) allow program designers to identify antecedents of dietary patterns and design effective interventions. The primary aim of this study was to examine the association between TPB variables and dietary patterns. A systematic literature search was conducted to identify relevant studies. Random-effects metaanalysis was used to calculate average correlations. Meta-regression was used to test the impact of moderator variables. In total, 22 reports met the inclusion criteria. Attitudes had the strongest association with intention (r + = 0.61) followed by perceived behavioral control (PBC, r + = 0.46) and subjective norm (r + = 0.35). The association between intention and behavior was r + = 0.47, and between PBC and behavior r + = 0.32. These associations were robust to the influence of key moderators. However, analyses revealed that younger participants had stronger PBC-behavior associations than older participants, and studies recording participants' perceptions of behavior reported significantly higher intentionbehavior associations than those using less subjective measures. Recommendations for future research include further examination of the moderation of TPB variables by age and gender and the use of more valid measures of eating behavior.3

Background The English network of stop-smoking services (SSSs) is among the best-value life-preserving clinical intervention in the UK NHS and is internationally renowned. However, success varies considerably across services, making it important to examine the factors that influence their effectiveness. Methods Data from 126 890 treatment episodes in 24 SSSs in 2009e10 were used to assess the association between intervention characteristics and success rates, adjusting for key smoker characteristics. Treatment characteristics examined were setting (eg, primary care, specialist clinics, pharmacy), type of support (eg, group, one-to-one) and medication (eg, varenicline, single nicotine replacement therapy (NRT), combination of two or more forms of NRT). The main outcome measure was abstinence from smoking 4 weeks after the target quit date, verified by carbon monoxide concentration in expired air. Results There was substantial variation in success rates across intervention characteristics after adjusting for smoker characteristics. Single NRT was associated with higher success rates than no medication (OR 1.75, 95% CI 1.39 to 2.22); combination NRT and varenicline were more successful than single NRT (OR 1.42, 95% CI 1.06 to 1.91 and OR 1.78, 95% CI 1.57 to 2.02, respectively); group support was linked to higher success rates than one-to-one support (OR 1.43, 95% CI 1.16 to 1.76); primary care settings were less successful than specialist clinics (OR 0.80, 95% CI 0.66 to 0.99). Conclusions Routine clinic data support findings from randomised controlled trials that smokers receiving stop-smoking support from specialist clinics, treatment in groups and varenicline or combination NRT are more likely to succeed than those receiving treatment in primary care, one-to-one and single NRT. All smokers should have access to, and be encouraged to use, the most effective intervention options.

The combination of economic and social costs associated with non-communicable diseases provide a compelling argument for developing strategies that can influence modifiable risk factors, such as discrete food choices. Models of behaviour, such as the Theory of Planned Behaviour (TPB) provide conceptual order that allows program designers and policy makers to identify the substantive elements that drive behaviour and design effective interventions. The primary aim of the current review was to examine the association between TPB variables and discrete food choice behaviours. A systematic literature search was conducted to identify relevant studies. Calculation of the pooled mean effect size (r+) was conducted using inverse-variance weighted, random effects meta-analysis. Heterogeneity across studies was assessed using the Q- and I2-statistics. Meta-regression was used to test the impact of moderator variables: type of food choice behaviour; participants’ age and gender. A total of 42 journal articles and four unpublished dissertations met the inclusion criteria. TPB variables were found to have medium to large associations with both intention and behaviour. Attitudes had the strongest association with intention (r+ = 0.54) followed by perceived behavioural control (PBC, r+ = 0.42) and subjective norm (SN, r+ = 0.37). The association between intention and behaviour was r+ = 0.45 and between PBC and behaviour was r+ = 0.27. Moderator analyses revealed the complex nature of dietary behaviour and the factors that underpin individual food choices. Significantly higher PBC-behaviour associations were found for choosing health compromising compared to health promoting foods. Significantly higher intention-behaviour and PBC-behaviour associations were found for choosing health promoting foods compared to avoiding health compromising foods. Participant characteristics were also found to moderate associations within the model. Higher intention-behaviour associations were found for older, compared to younger age groups. The variability in the association of the TPB with different food choice behaviours uncovered by the moderator analyses strongly suggest that researchers should carefully consider the nature of the behaviour being exhibited prior to selecting a theory.Electronic supplementary materialThe online version of this article (doi:10.1186/s12966-015-0324-z) contains supplementary material, which is available to authorized users.