Development and exploratory cluster-randomised opportunistic trial of a theory-based intervention to enhance physical activity among adolescents

This article reports the development and exploratory testing of a school-based intervention programme designed to enhance levels of physical activity in adolescents. The intervention is based on social cognitive theory (SCT), self-regulation theory (SRT) and planning as evidence-based mediators of physical activity changes. Two classes, paired on socio-economic variables, were selected from each of eight Portuguese schools and randomly assigned to an intervention or control group (N = 291). Primary outcome was ‘moderate to vigorous physical activity’ (International Physical Activity Questionnaire) measured pre and post intervention and at three and nine months follow-up. SCT, SRT and planning variables were secondary outcomes measured pre and post intervention. At post test, participants in the intervention group reported 18 min per week more physical activity (PA), adjusted for pre-intervention, age and sex, than those in the control group (95% confidence interval ?10 to 46; p = 0.249). This difference increased to 33 min (95% CI–4 to 71; p = 0.082) at three months and to 57 min (95% CI 13 to 101, p = 0.008) at nine month follow-up. Moreover, the intervention resulted in changes of some of the theoretical target variables, including outcome expectancies and coping planning. However, no evidence was found for the changes in theoretical moderators to mediate the intervention effects on behaviour. Implications for theory and for future research are discussed.     

A cluster randomised controlled trial of an intervention based on the Health Action Process Approach for increasing fruit and vegetable consumption in Iranian adolescents

Objective: To evaluate an intervention programme based on the Health Action Process Approach and designed to increase the intake of fruit and vegetables (F&V) among Iranian adolescents aged 13 to 18.

Design: A randomised controlled trial with three arms examined the short- (1 month) and long-term (6 months) effects of the intervention. There were two intervention groups (one included adolescents only [A group; n = 510]; the second included mothers and adolescents [M + A group; n = 462]) and a control group (n = 483). All participants were recruited from schools.

Main outcome measures: Social cognitions, self-regulatory processes and F&V intake.

Results: The intervention led to an increase in F&V intake for adolescents in the short and long terms. Adolescents in the M + A group increased their F& V intake more than adolescents in the A group. Outcome expectancies, self-monitoring, intentions, action and coping planning, perceived social support and behavioural automaticity mediated the effect of the intervention on F&V intake.

Conclusion: The theory-based intervention led to an increase in F&V intake and promoted more positive social cognitions and self-regulatory processes among Iranian adolescents. The findings also provide evidence that involving mothers in an intervention can confer additional benefit.     

Pathway to health: cluster-randomized trial to increase fruit and vegetable consumption among smokers in public housing.

OBJECTIVES: Examine the effectiveness of an intervention to increase fruits and vegetables (FV) consumption among smokers. DESIGN: Cluster-randomized trial of 20 public housing developments; 10 randomly assigned to an FV intervention and 10 to a smoking cessation intervention. MAIN OUTCOME MEASURES: Usual (past 7 days) and past 30 days change in daily FV intake at 8 weeks and 6 months postbaseline. RESULTS: Greater increases were seen in the FV group. At Week 8 and Month 6, the FV group had consumed 1.58 (p = .001) and 0.78 (p = .04), respectively, more daily FV servings in the past 7 days than the cessation group. At the same time points, the FV group had consumed 3.61 (p = .01) and 3.93 (p = .01), respectively, more FV servings in the past 30 days than the cessation group. Completing more motivational interviewing sessions (p = .02) and trying more recipes (p = .02) led to significantly greater increases at Month 6 among FV participants. CONCLUSIONS: Motivational interviewing counseling and lifestyle modification through trying out healthy recipes may be effective in helping a high-risk population increase their FV intake.     

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.     

Motivational interviewing and self-determination theory in a web-based computer tailored physical activity intervention: A randomized controlled trial

Objective: This study explores whether a web-based physical activity (PA) intervention grounded in self-determination theory (SDT) and motivational interviewing (MI) is more effective and better appreciated than a traditional web-based PA intervention.

Design: A randomized controlled trial was conducted, comparing (1) I Move; a web-based PA intervention based on SDT and MI, (2) Active Plus; a traditional web-based PA intervention and (3) a waiting list control condition.

Main outcome measures: Weekly minutes of moderate to vigorous PA and weekly days with ≥30 min PA were measured through self-report at baseline and at 3 and 6 months from baseline.

Results: I Move achieved a small, but significant increase in weekly minutes of moderate to vigorous PA, while Active Plus did not have a significant impact on this outcome. Both interventions were effective in increasing weekly days with ≥30 min PA, whereas Active Plus yielded a greater effect on this outcome.

Conclusion: Overall, the web-based PA intervention grounded in SDT and MI did not outperform the traditional web-based PA intervention. Further research should reveal whether this type of intervention is profitable for long-term maintenance of PA levels.     

Emotional intelligence and aggression among South African adolescents: Preliminary evidence

We investigated gender differences in emotional intelligence and aggression among South African adolescents. Four hundred and forty-four adolescents (female =51.4 %; mean age =15.5 years, SD= 1.42 years; rural residence = 35.5%, urban residence = 65.5%) completed an emotional intelligence scale and an aggression expression survey. Exploratory independent sample t-test analysis revealed female adolescents to score higher on perception of and management of emotions than male adolescents. Female adolescents also scored higher on verbal aggression than their male peers, whereas male adolescents scored higher on physical aggression than the female adolescents.     

Relationships between self-regulation skills and physical activity and fruit and vegetable consumption in obese adults: mediation of mood and self-efficacy

In cognitive-behavioral treatments for obesity, self-regulation is thought to be a strong predictor of behavioral change, but it is rarely directly measured in intervention research. Thus, how self-regulation interacts with other psychological variables regarding treatment effects is largely unknown. In this preliminary field study, self-regulatory skills were directly measured and were found to be significantly associated with both volume of exercise and fruit and vegetable consumption in severely obese adults (N=116) enrolled in a behavioral weight management program. Significant partial and complete mediation of the relationship between self-regulation for physical activity and physical activity, and self-regulation for appropriate eating and fruit and vegetable intake, respectively, were found by reported negative mood. Self-efficacy was not found to be a significant mediator of these relationships. The bivariate relationship between baseline scores of self-regulation for physical activity and self-regulation for appropriate eating was significant (r = .46), which supported the premise that self-regulation is a trait-like personal characteristic. Volume of exercise and fruit and vegetable consumption significantly predicted weight loss over 6 months (R2 = .35). Results were consistent with the few laboratory-based findings available and, after replication, may extend theory related to obesity treatment.     

Relations among weight control behaviors and eating attitudes, social physique anxiety, and fruit and vegetable consumption in Turkish adolescents

This study examined the relationship among dieting, eating attitudes, social physique anxiety, and fruit and vegetable consumption among Turkish adolescents. Abnormal eating behavior (EAT-26 > or =20) was found in 32.8% of the total sample; this included 26.4% of the males and 38.7% of the females. Weight-control and weight-related behaviors are associated with high fruit and vegetable consumption in adolescents. Dieting was significantly associated with types of consumption in female adolescents. In addition, EAT-26 scores were significantly positively correlated with high fruit and vegetable consumption, but this association was not observed in SPAS scores among adolescents. Adolescents who engage in dieting behaviors seem to consume more fruit and vegetables than do other adolescents. Female adolescents may be more likely to display abnormal eating attitudes and dieting behaviors than do males. Although some weight-control behaviors may be risky, adolescents who were practicing dieting behaviors engaged in the positive dietary behavior of consuming more servings of fruit and vegetables than did non-dieters.     

Conscientiousness and fruit and vegetable consumption: exploring behavioural intention as a mediator

Clear associations have emerged between conscientiousness and health behaviours, such that higher levels of conscientiousness are predictive of beneficial health behaviours. This study investigated the conscientiousness-fruit and vegetable consumption relationship and whether behavioural intention mediated this relationship. A large sample of adults (N = 2136) completed an online battery of questionnaires measuring conscientiousness, behavioural intentions to consume fruit and vegetables, together with self-reported behaviour. Correlation analysis revealed that conscientiousness and each of its facets were positively associated with behavioural intention and self-reported behaviour. Hierarchical multiple regression analyses revealed that after controlling for age, gender and education, total conscientiousness, and the facets of responsibility, industriousness, order and virtue predicted self-reported behaviour. Further analysis revealed that in line with the Theory of Planned Behaviour, behavioural intention fully mediated the conscientiousness-fruit and vegetable behaviour relationship. In conclusion, low levels of conscientiousness were found to be associated with lower fruit and vegetable intentions, with the latter also associated with fruit and vegetable consumption.     

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.     

Trauma exposure and life satisfaction among at-risk black South African adolescents

This study aimed to construct a model to explain trauma exposure and life satisfaction among black South African school learners. A random sample of 366 black adolescents selected from ten South African schools participated (females = 63.2%; rural = 24.2%; mean age = 13.9 years). The school learners were surveyed on trauma exposure, resources, coping and resilience, and life satisfaction. A structural equation modelling analysis indicated that interpersonal, intrapersonal and affective strengths, coping skills, family involvement, and school functioning were associated with increased resilience, which in turn predicted life satisfaction. Interventions aimed at increasing resilience in contexts characterised by high levels of trauma exposure should prioritise helping adolescents access both internal and external resources, such as coping skills and family involvement respectively.     

A brief intervention to increase physical activity behavior among adolescents using mental simulations and action planning

This study evaluated the effectiveness of a brief integrated theory-based intervention to increase physical activity (PA) among adolescents over a three-month follow-up period. A 2 (mental simulation: present vs. absent) × 2 (action planning: present vs. absent) × 4 (time: baseline vs. one-month vs. two-month vs. three-month follow-up) mixed-model randomized controlled design was adopted. Adolescents aged 14–15 years (N = 267) completed baseline psychological measures and self-reported PA followed by the relevant intervention manipulation, if appropriate, with follow-up measures collected one, two, and three months later. Results revealed no significant effects for the mental simulation and action planning strategies nor the interaction of the two strategies. However, among participants with low levels of baseline PA, participants in both mental simulation alone and action planning alone groups reported significantly higher levels of PA at one-month follow up than other groups, suggesting that individual intervention components may be effective in low-active adolescents.     

Dietary planning,self-efficacy,and outcome expectancies play a role in an online intervention on fruit and vegetable consumption

Objective: An online intervention to improve fruit and vegetable (FV) intake examines the role of planning, outcome expectancies, self-efficacy and gender. Women are not only expected to eat more FV than men, but they are also expected to be more responsive to nutritional advice and benefit more from treatment.

Method: A two-arm digital intervention with 269 men and 395 women (M_age = 41.2, SD_age = 11.45; range: 19–66 years) was conducted in Italy, Spain and Greece, followed up at three and six months, comparing a static with a dynamic, feedback-intensive platform.

Results: Linear mixed models yielded an increase in FV consumption in both the dynamic and the static intervention arms. In men, outcome expectancies were positively related to follow-up FV intake. Dietary planning interacted with self-efficacy on behavioural outcomes.

Conclusion: FV intake increased overall, and being a woman and involvement in planning facilitated behaviour change. Women seemed to be more engaged in the dynamic platform resulting in a higher amount of planning. Initial motivation, as indicated by outcome expectancies, seemed to be beneficial for men. Self-efficacious individuals benefitted from their engagement in planning, but self-efficacy did not compensate for failing to plan.     

Efficacy of guided self-help behavioural activation and physical activity for depression: a randomized controlled trial

Behavioural activation and physical activity have received empirical support that highlight their efficacy in reducing depression. Even though both behavioural activation and physical activity share the common goal of reactivating the individual, limited research has directly compared these interventions, and more research is required to evaluate their efficacy when offered in low-intensity formats. The present study involves a randomized controlled clinical trial comparing the efficacy of two guided self-help interventions for the treatment of depression: behavioural activation and physical activity. Fifty-nine participants presenting mild-to-moderate symptoms of depression were randomized either to a behavioural activation intervention (n = 20), a physical activity intervention (n = 19) or a wait-list control group (n = 20). All participants completed symptom measure pre-, mid- and post-intervention, as well as at a two-month follow-up. Mixed-model analyses of variance revealed that both interventions were significantly more efficacious in reducing depressive symptoms in comparison with the control group. Physical activity involved significantly less time-investment compared to the behavioural activation condition (less than half the amount of time). These results indicate that physical activity and behavioural activation both effectively reduce depressive symptoms and are favourably applicable in low-intensity formats. Implications of these results and avenues for future research are discussed.     

Stress and happiness among adolescents with varying frequency of physical activity

The aim of this cross-sectional study was to investigate associations between physical activity, stress, and happiness, as well as possible sex and age differences on these variables in a survey of 1,508 adolescent pupils (13 to 18 yr.) in middle Norway. Adolescents who reported they participated in physical activity 2 to 3 times per week or more scored significantly lower on stress and higher on happiness than those who participated in physical activity 1 day per week or less. There was no significant difference on stress and happiness between those being physically active 2 or 3 times a week and those being active almost every day. There was no sex difference in physical activity frequency. Girls had higher mean scores on stress, and boys scored higher on happiness. Adolescents 15 to 16 years old showed higher stress scores than those 17 to 18 years old, but there were no significant differences between the different age groups when looking at happiness and physical activity. A statistically significant two-way interaction of sex by age was found on both stress and happiness.     

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.