The impact of self-efficacy and implementation intentions-based interventions on fruit and vegetable intake among adults

This study tested the effect of interventions designed for people who do not eat yet the recommended daily fruit and vegetable intake (FVI) but have a positive intention to do so. Adults (N?=?163) aged 20-65 were randomised into four groups: implementation intentions (II group), self-efficacy (SE group), combination of II?+?SE group) and a control group receiving written information on nutrition. Study variables were measured at baseline, post-intervention and at 3-month follow-up. At follow-up, compared to the control group, FVI increased significantly in the II and II?+?SE groups (1.5 and 1.9 servings per day, respectively). Most psychosocial variables significantly increased compared to the control group, with the exception of SE for vegetable intake (VI). Moreover, at 3-month follow-up, change in FVI was mediated by changes in fruit intake (FI) intention and VI action planning. In conclusion, II interventions were efficient to increase FVI, with or without consideration for the development of SE. Thus, future studies should favour the adoption of this approach to bridge the intention-behaviour gap for FVI.     

Planning and self-efficacy interventions encouraging replacing energy-dense foods intake with fruit and vegetable: A longitudinal experimental study

Objective: This longitudinal experimental study compared effects of self-efficacy, planning and education-based conditions, encouraging adolescents to eat fruit and vegetable in place of energy-dense foods.

Design: Data were collected among 506 adolescents (13–18 years old) who were randomly assigned to control (n = 181), planning (n = 153) or self-efficacy (n = 172) conditions. Measurements were taken at baseline (T1), at a 2-month follow-up (T2), and at a 14-month follow-up (T3). Interventions/control group procedures were delivered at T1 and T2.

Outcome measures: Self-reports of fruit and vegetable intake (FVI) and energy-dense foods intake were collected at three times. Cognitive mediators (self-efficacy and planning) were assessed at T1 and T2. Body weight and height were objectively measured at T1 and T3.

Results and conclusions: Similar significant increases of FVI were found for planning and self-efficacy interventions (T3). The planning intervention did not influence energy-dense food intake (T3), but the self-efficacy intervention tended to result in stabilising intake (compared to an increase found in the control group). There were no effects on body weight. Similar patterns were found for the total sample and for a subsample of adolescents with overweight/obesity. The effects of interventions on FVI were mediated by respective cognitions.     

How planning facilitates behaviour change: Additive and interactive effects of a randomized controlled trial

Planning interventions have proven effective to change behaviour. However, less is known about their underlying mechanisms. To better understand the processes by which planning interventions unfold their effects, a combined action planning and coping planning intervention was tested in a field setting, with the focus on mediating and moderating effects of theory‐derived social‐cognitive variables. In a randomized controlled trial, 374 employees of a logistics company were asked to participate in either a combined action planning and coping planning intervention or an active control group. Four weeks later, self‐reported changes in fruit and vegetable intake, action planning, coping planning, intentions and self‐efficacy were measured. Single and simultaneous mediating effects on behaviour were tested with intention‐to‐treat analyses, along with interaction effects between planning processes. Action planning and coping planning mediated intervention effects on fruit and vegetable intake not only separately, but also simultaneously (multiple mediation). Action planning and coping planning had main and interactive effects on behaviour change (moderation). Action planning and coping planning may exert both additive and synergistic effects on health behaviour change. Volitional interventions should include both action planning and coping planning components and stimulate the use of planning in everyday life. Copyright © 2009 John Wiley & Sons, Ltd.     

Psychosocial mediation of fruit and vegetable consumption in the body and soul effectiveness trial.

In this study the authors examined psychosocial variables as mediators for fruit and vegetable (FV) intake in a clustered, randomized effectiveness trial conducted in African American churches. The study sample included 14 churches (8 intervention and 6 control) with 470 participants from the intervention churches and 285 participants from the control churches. The outcome of FV intake and the proposed mediators were measured at baseline and at 6-month follow-up. Structural equation modeling indicated that the intervention had direct effects on social support, self-efficacy, and autonomous motivation; these variables also had direct effects on FV intake. Applying the M. E. Sobel (1982) formula to test significant mediated effects, the authors confirmed that social support and self-efficacy were significant mediators but that autonomous motivation was not. Social support and self-efficacy partially mediated 20.9% of the total effect of the intervention on changes in FV intake. The results support the use of strategies to increase social support and self-efficacy in dietary intervention programs.     

Cognitive-behavioural health-promotion intervention increases fruit and vegetable consumption and physical activity among South African adolescents: a cluster-randomised controlled trial

Rates of chronic diseases are high among Black South Africans but few studies have tested cognitive-behavioural health-promotion interventions to reduce this problem. We tested the efficacy of such an intervention among adolescents in a cluster-randomised controlled trial. We randomly selected 9 of 17 matched pairs of schools and randomised one school in each pair to the cognitive-behavioural health-promotion intervention designed to encourage health-related behaviours and the other to a human immunodeficiency virus (HIV)/sexually transmitted disease (STD) risk-reduction intervention that served as the control. Interventions were based on social cognitive theory, the theory of planned behaviour and qualitative data from the target population. Data collectors, blind to participants' intervention, administered confidential assessments at baseline and 3, 6 and 12 months post-intervention. Primary outcomes were fruit and vegetable consumption and physical activity. Participants were 1057 grade 6 learners (mean age = 12.4 years), with 96.7% retained at 12-month follow-up. Generalised estimating equations revealed that averaged over the follow-ups, a greater percentage of health-promotion intervention participants than HIV/STD control participants met 5-a-Day fruit and vegetable and physical activity guidelines. The intervention also increased health-promotion knowledge, attitude and intention, but did not decrease substance use or substance-use attitude and intention. The findings suggest that theory based and contextually appropriate interventions may increase health behaviours among young adolescents in sub-Saharan Africa.     

Can personality close the intention-behavior gap for healthy eating? An examination with the HEXACO personality traits

The aim of this study was to investigate the predictive and moderating effects of HEXACO personality factors, in addition to theory of planned behavior (TPB) variables, on fruit and vegetable consumption. American college students (N = 1036) from 24 institutions were administered the TPB, HEXACO and a self-reported fruit and vegetable consumption measure. The TPB predicted 11–17% of variance in fruit and vegetable consumption, with greater variance accounted for in healthy weight compared to overweight individuals. Personality did not significantly improve the prediction of behavior above TPB constructs; however, conscientiousness was a significant incremental predictor of intention in both healthy weight and overweight/obese groups. While support was found for the TPB as an important predictor of fruit and vegetable consumption in students, little support was found for personality factors. Such findings have implications for interventions designed to target students at risk of chronic disease.     

Predictors of physical activity,healthy eating and being smoke-free in teens: A theory of planned behaviour approach

This paper elicited context specific underlying beliefs for physical activity, fruit and vegetable consumption and smoke-free behaviour from the Theory of Planned Behaviour (TPB), and then determined whether the TPB explained significant variation in intentions and behaviour over a 1 month period in a sample of grade 7–9 (age 12–16 years) adolescents. Eighteen individual interviews and one focus group were used to elicit student beliefs. Analyses of this data produced behavioural, normative and control beliefs which were put into a TPB questionnaire completed by 183 students at time 1 and time 2. The Path analyses from the main study showed that the attitude/intention relationship was moderately large for fruit and vegetable consumption and small to moderate for being smoke free. Perceived behavioural control had a large effect on being smoke free and a moderately large effect for fruit and vegetable consumption and physical activity. Intention had a large direct effect on all three behaviours. Common (e.g. feel better, more energy) and behaviour-specific (e.g., prevent yellow fingers, control my weight) beliefs emerged across the three health behaviours. These novel findings, to the adolescent population, support the importance of specific attention being given to each of the behaviours in future multi-behavioural interventions.     

Neuroticism,conscientiousness and fruit consumption: Exploring mediator and moderator effects in the theory of planned behaviour

Integrating the theory of planned behaviour (TPB) with the five-factor model (FFM) of personality may provide insight into the cognitive and motivational mechanisms linking personality with health behaviour, but this issue has received very little attention regarding fruit consumption. Mediator effects of TPB concepts in the personality–fruit consumption link, as well as moderator effects of personality in the intention–fruit consumption link, were therefore investigated in the present study. Data on fruit consumption, TPB concepts and FFM dimensions were gathered among 405 respondents in face-to-face interviews using questionnaires. Structural equation modelling was used to investigate the mediator and moderator effects. The direct effect of conscientiousness on fruit consumption was mediated by attitude and perceived behavioural control, while no direct effect of neuroticism on fruit consumption was found. Neuroticism moderated the intention–fruit consumption relationship with the weakest relationship for those scoring high on neuroticism. Conscientiousness did not moderate the intention–fruit consumption relationship. TPB variables are mediators in the conscientiousness–fruit consumption link. Whether fruit consumption is intentional may be dependent upon the personality dimension neuroticism. Personality dimensions may be a useful addition to the TPB and should be considered in health behaviour change interventions.     

Psychological and social predictors of changes in fruit and vegetable consumption over 12 months following behavioral and nutrition education counseling.

This study assessed psychological and social factors predicting 12-month changes in fruit and vegetable consumption achieved by 271 men and women from a low-income population randomized to brief behavioral and nutrition education counseling. Greater increases in fruit and vegetable intake were achieved in the behavioral than in the nutrition education condition (1.49 vs. 0.87 portions per day, p=.021). Increases were predicted by baseline social support for dietary change but not by baseline psychological measures. However, short-term (8-week) changes in dietary self-efficacy, encouragement, anticipated regret, perceived benefits, and knowledge of recommended intake predicted 12-month changes in fruit and vegetable consumption independently of gender, age, ethnicity, income, and baseline intake. These factors accounted for 51% of the superiority of behavioral counseling over nutrition education.     

Bi-Directional Relationship Between Self-Regulation and Improved Eating: Temporal Associations With Exercise,Reduced Fatigue,and Weight Loss

ABSTRACT. Severely obese men and women (body mass index ≥ 35 ≤ 55 kg/m²; M_age = 44.8 years, SD = 9.3) were randomly assigned to a 6-month physical activity support treatment paired with either nutrition education (n = 83) or cognitive-behavioral nutrition (n = 82) methods for weight loss. Both groups had significant improvements in physical activity, fatigue, self-regulation for eating, and fruit and vegetable intake. Compared to those in the nutrition education group, participants in the behavioral group demonstrated greater overall increases in fruit and vegetable intake and physical activity. These group differences were associated with changes that occurred after Month 3. Increased physical activity predicted reduced fatigue, β = ?.19, p =.01. A reciprocal relationship between the mediators of that relationship, which were changes in self-regulation and fruit and vegetable intake, was identified. There was significantly greater weight loss over six months in the behavioral nutrition group when contrasted with the nutrition education group. Self-regulation for eating and fruit and vegetable intake were significant predictors of weight loss over both three and six months. Findings enabled a better understanding of psychosocial effects on temporal aspects of weight loss and may lead to more effective behavioral treatments for weight loss.     

Comparing implementation intention interventions in relation to young adults’ intake of fruit and vegetables

This study tests whether the effectiveness of implementation intention-based interventions to increase fruit and vegetable intake in a young adult population can be enhanced using additional pre-intervention instructions and alternative formats; namely, an ‘if-then’ implementation intention versus a more general, ‘global’ plan that does not explicitly link a situational cue with a goal-directed response. Participants (N?=?557) completed pre-test measures of planning, motivation and behaviour with respect to increasing their fruit and vegetable intake before being randomised to a 3 (intervention format: control vs. ‘if-then’ vs. ‘global’ implementation intentions)?×?2 (pre-intervention instruction vs. no pre-intervention instruction) between-participants design. Results revealed a significant intervention format by time interaction, such that intake significantly increased by 0.50 portions in the if-then format condition compared with 0.31 in the global format and 0.01 in the control condition. These results suggest that ‘if-then’ manipulations are superior in promoting behaviour change in an applied setting. The use of pre-intervention instructions had no additional effect on behaviour, providing evidence for the efficacy of implementation intentions even when experimenter demand is reduced. Evidence is also presented to suggest that reported increases in intake are not related to demand characteristics.     

Health messages to promote fruit and vegetable consumption at different stages: A match-mismatch design

Objective: To examine the effectiveness of matching health messages promoting fruit and vegetable intake to the Health Action Process Approach stages of change.

Design: In a randomised controlled trial, 205 undergraduate students (non-intenders n = 123; intenders n = 82) were exposed to one of three health messages, targeted at non-intenders, intenders and controls.

Main outcome measures: Three longitudinal assessments of stage, fruit and vegetable intake, and social-cognitive determinants were obtained.

Results: Stage-specific effects of the interventions were confirmed. For self-efficacy, a stage by health message crossover interaction emerged, with both non-intenders and intenders in the matched conditions scoring higher in self-efficacy. Furthermore, in line with predictions, non-intenders in the matched condition showed higher risk perception, outcome expectancies, intention, and stage progression immediately after message exposure, and lower levels of action planning and coping planning a week later in the mismatched condition, but for these outcomes no differences across conditions were obtained among intenders. Multiple mediation analyses confirmed the facilitating role of self-efficacy and behavioural intention among non-intenders.

Conclusions: Stages should be considered when designing health messages, although more interactive interventions for intenders and extended measurement time frames may be required.     

Fruit and Vegetable Intake Predicts Positive Affect

Prior research suggests that fruit and vegetable intake predicts psychological well-being (WB) when controlled for demographic variables such as age, income and education. Using multiple-item measures and including additional diet and health variables as covariates, the current study assessed self-reported well-being in the past week and daily fruit and vegetable consumption over the past 4 weeks for 1270 university students. Mean positive affect increased linearly as a function of number of daily servings of fruits and vegetables; the pattern of this relationship did not differ significantly for males and females. This association remained statistically significant after controlling for demographic variables (age, sex, and parent education levels); other diet variables (consumption of sugar containing beverages, coffee or tea, and fat); and other health behaviors (exercise, sleep quality and smoking). Life satisfaction and negative affect were not significantly related to fruit and vegetable consumption. Analysis of single-item measures similar to those used in past large scale surveys yielded similar results. Possible reasons for the association of fruits and vegetable consumption with well-being are discussed.     

Predicting 2-year weight loss through temporally specific earlier losses,relevant behaviors,and their psychological correlates: Implications for behavioral treatment architectures

Maintaining loss of weight beyond an initial 6–9 months remains problematic, with research indicating little recent progress. A poor understanding of how and when prior weight loss, behavioral changes, and psychosocial predictors are associated with long-term weight changes persists. To better-inform behavioral treatments for long-term success with weight loss, women with obesity (N = 86; M_age = 48.6 years) volunteered for research incorporating community-based weight-management treatments. They were assessed at months 6, 12, and 24 on theory-based psychosocial and behavioral factors, and over 24 months on weight. Considering the included times and temporal ranges, it was found that change in weight from month 6–24 was the strongest predictor of 24-month weight change, and physical activity and fruit/vegetable intake at month 24 best predicted that change in weight. Self-regulation, self-efficacy, and mood at month 24 best predicted both physical activity and fruit/vegetable intake at month 24, with body satisfaction also a significant predictor of physical activity. From these data, mediation analyses found that the predictions of long-term weight loss by scores of self-regulation, self-efficacy, body satisfaction, and mood at month 24 were significantly mediated by fruit/vegetable intake and physical activity in separate equations. Findings indicated both psychosocial and behavioral targets, and timing for those targets, most indicative of long-term success with weight loss.     

The Effects of Positive Interventions on Happiness and Depressive Symptoms, with an Examination of Personality as a Moderator

The advent of positive psychology has triggered research into positive interventions, which focus on strengths instead of deficits. The present study aims to investigate the effects of gratitude and strengths-based interventions on happiness and depressive symptoms against a control group, as well as to explore personality traits as moderator variables of the potential effectiveness of these interventions. A total of 122 participants completed at least two stages of the research. Data were collected at three stages—baseline pre-test, post-intervention assessment, and 1-month follow-up assessment. The findings partially support the effectiveness of the gratitude and strengths-based interventions in increasing happiness and decreasing depressive symptoms compared to a control group. Two personality domains showed significance as moderator variables. More research is needed to enable a higher degree of control when administering these promising interventions.     

A randomized controlled trial of single versus multiple health behavior change: promoting physical activity and nutrition among adolescents.

Targeting multiple behaviors for change may provide significant health benefits. This study compared interventions targeting physical activity and nutrition (PAN) concurrently versus physical activity (PA) alone. Adolescents (N=138) were randomized to the PAN or PA intervention or control condition (n=46 per group). Primary outcomes were change in PA accelerometer and 3-day dietary recording from baseline to 3-month follow-up. The PAN and PA interventions were efficacious in supporting boys' (p<.001) but not girls' (p=.663) PA relative to the control condition. Dietary change was minimal. Although the findings do not reveal a decrement to PA promotion when a nutrition intervention was added, neither do they reveal any additional benefit. More studies comparing single versus multibehavioral interventions are needed.     

Evaluating the Effectiveness of a Group CBT for Parents of ADHD Children

Improvements in parenting skills do not necessarily lead to improvements in child and parent outcomes for children with attention deficit and hyperactivity disorder (ADHD). Cognitive factors such as parental cognitions and parenting self-efficacy may influence such outcomes. Clinical research on the effects of cognitive-behaviour therapy (CBT) on parental cognitions, parenting self-efficacy and mental health in Chinese parents of children with ADHD is lacking. This quasi-experimental study intended to assess the effects of a culturally attuned group CBT treatment on the mental health and quality of life of Chinese parents aged 26–58 years, with children with ADHD in Hong Kong. Participants in the experimental group received group CBT and standard treatment and their counterparts in the control group received standard treatment. Primary outcome variables of mental health and quality of life and process variables including parenting stress, parenting efficacy and dysfunctional attitudes were measured at baseline, post-treatment and 3-month follow-up. Data were analysed using 2?×?3 ANCOVAs, Cohen’s d statistics and multiple mediation analyses. Group by time interactions were found for most outcome variables. Effect size statistics indicated that group CBT had small to moderate effects on most outcome variables at post-treatment and follow-up assessments. The effect of CBT on mental health was mediated by the reduction in parenting stress and the effect of CBT on quality of life was mediated by the reductions in parenting stress and dysfunctional attitudes. Given its potential benefit, it is worth considering incorporating this group CBT programme into interventions for Chinese parents with ADHD children.     

A psychological intervention reduces doping likelihood in British and Greek athletes: A cluster randomized controlled trial

BackgroundCurrent attempts to prevent doping through deterrence and education have had limited success and have been constrained to one country. Targeting psychological variables that have been empirically associated with doping likelihood, intention, or behaviour may help in developing interventions that are effective in preventing doping in sport.ObjectivesGuided by social cognitive theory and empirical research, the main purpose of this research was to develop an anti-doping intervention that targets three psychological variables (i.e., anticipated guilt, moral disengagement, and self-regulatory efficacy) and determine whether it is more effective than an educational intervention in reducing doping likelihood in British and Greek athletes.MethodEligible participants were identified via a screening survey administered to 934 athletes in the United Kingdom and Greece. A total of 19 sport clubs (208 athletes) across the two countries were randomly assigned to either the psychological or the educational intervention. Each intervention consisted of six 1-h sessions delivered to small groups of athletes over 6–8 weeks. Athletes completed measures of doping likelihood, anticipated guilt, moral disengagement, and self-regulatory efficacy pre and postintervention and at a 2-month follow-up.ResultsA multilevel piecewise growth model was used to examine changes in study outcomes. Analysis showed that the psychological intervention was more effective than the educational intervention in reducing doping likelihood from pre to post, but the effects of the two interventions were similar at follow-up. These effects were not affected by country. Both interventions reduced moral disengagement from pre to post, and these effects were maintained at follow-up. The psychological intervention was also more effective than the educational intervention in increasing anticipated guilt from pre to follow-up.ConclusionsTargeting psychological variables in anti-doping interventions should aid our efforts to prevent doping in sport.     

Self-regulation versus habit: the influence of self-schema on fruit and vegetable consumption

The aim of this study is to examine the determinants of fruit and vegetable (F&V) consumption with the application of the Theory of Planned Behaviour (TPB) and the additional variables of self-schema, habit and self-regulation. While it has been shown that those with a healthy-eater self-schema are more likely to carry out their healthy dietary intentions, the underlying processes that influence this relationship have received limited empirical attention. Recent findings on dietary behaviour suggest that self-regulatory ability and habit strength may have dissimilar effects on the intention-behaviour relationship within schematics and non-schematics. Self-report questionnaires regarding F&V consumption cognitions and two tests of self-regulation were administered to 209 university students. One week later, participants completed questionnaires on their behaviour. The TPB significantly predicted intentions and prospective behaviour. Self-schema did not moderate the relationship between intention and behaviour. However, within healthy-eater schematics, those with high intention and high self-regulatory ability were more likely to consume F&V, while within non-schematics, those with low intention and high habit strength were more likely to consume F&V. The findings support the use of the TPB in predicting F&V consumption and the validity of the self-schema distinction. Implications for designing interventions are discussed.     

Secondary smoking prevention in a university setting: a randomized comparison of an experiential, theory-based intervention and a standard didactic intervention for increasing cessation motivation.

OBJECTIVE: College may represent an untapped opportunity to reach the growing number of student smokers who are at risk of progressing toward regular smoking. The aim of this study was to test the efficacy of a theory-based experiential intervention for increasing motivation to quit smoking and reducing smoking behavior. DESIGN: This study used a 3-arm, randomized design to examine the efficacy of an experiential secondary prevention intervention. The control groups included a traditional didactic smoking intervention and an experiential intervention on nutrition. MAIN OUTCOME MEASURES: The 2 primary dependent variables were change in self-reported intention to quit smoking, measured pre- and postintervention, and change in smoking behavior over the month following the intervention. RESULTS: As hypothesized, the experiential smoking intervention was more effective than either control group in increasing immediate motivation to quit, but the effect was found only among female participants. At 1-month follow-up, both smoking interventions produced higher rates of smoking cessation and reduction than did the nutrition control condition. CONCLUSION: Findings support the potential efficacy of an intensive experiential intervention for female smokers.