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

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.

Quinoa is a pseudo-grain consumed as a dietary staple in South America. In recent years, consumer demand for quinoa in the developed world has grown steadily. Its perceived health benefits have been cited as a driving force behind this trend, but there are very few human studies investigating the impact of quinoa consumption. The aim of this review was to identify physiological effects of quinoa consumption with potential for human health. A critical evaluation of animal model studies was conducted. The quality of identified studies was assessed using a methodological quality assessment tool and summative conclusions were drawn to guide the direction of future human research. The majority of studies were of fair quality. Purported physiological effects of quinoa consumption included decreased weight gain, improved lipid profile and improved capacity to respond to oxidative stress. These physiological effects were attributed to the presence of saponins, protein and 20-hydroxyecdysone in the quinoa seed. The implications of these findings are that human studies should investigate the impact of quinoa consumption on weight gain and lipid levels. The role of quinoa as an antioxidant is still unclear and requires further elucidation in animal models. Disciplines Medicine and Health Sciences | Social and Behavioral Sciences AbstractQuinoa is a pseudo-grain consumed as a dietary staple in South America. In recent years, consumer demand for quinoa in the developed world has grown steadily. Its perceived health benefits have been cited as a driving force behind this trend, but there are very few human studies investigating the impact of quinoa consumption.The aim of this review was to identify physiological effects of quinoa consumption with potential for human health. A critical evaluation of animal model studies was conducted. The quality of identified studies was assessed using a methodological quality assessment tool and summative conclusions were drawn to guide the direction of future human research. The majority of studies were of fair quality. Purported physiological effects of quinoa consumption included decreased weight gain, improved lipid profile and improved capacity to respond to oxidative stress. These physiological effects were attributed to the presence of saponins, protein and 20-2 hydroxyecdysone in the quinoa seed. The implications of these findings are that human studies should investigate the impact of quinoa consumption on weight gain and lipid levels. The role of quinoa as an antioxidant is still unclear and requires further elucidation in animal models.

Studies were divided into those that investigated the effect of sorghum on chronic disease and those that investigated other effects of sorghum on health. There was evidence that the consumption of sorghum attenuated blood glucose responses and decreased the expression of markers of oxidative stress. Sorghum was also observed to be a suitable ingredient for the formulation of oral rehydration solutions and showed potential for use as a medical adjunct to boost immune responses in HIV-positive patients CONCLUSIONS: The implication is that sorghum may have attributes superior to those of other staple grains, indicating its potential for innovative uses in commercial foods. More work is required to elucidate the health effects of sorghum when consumed by population groups that have not been traditional consumers of the grain.