A randomised controlled trial of a theory of planned behaviour to increase fruit and vegetable consumption. Fresh Facts

Modeling fruit and vegetable consumption in Serbia

Although regular intake of fruits and vegetables has an essential role in a healthy diet and well-being, a majority of consumers in Serbia have a suboptimal intake of these groceries. To understand the main determinants of this unsatisfactory situation, the study tested an extended model of the theory of planned behavior intending to suggest necessary steps for improving fruits and vegetables daily intake. This theory, extended for the role of knowledge, was tested using structural equation modeling. Fit indices confirmed the utility of this extended model of the theory of planned behavior in explaining consumers' behavior as well as the mediating role of behavioral intentions. Serbia, as one of the central developing countries in the Balkans, was chosen to test the model with the possibility of applying it to other developing countries facing malnutrition. Data were collected in North Serbia, through an online survey (n=688). Despite consumers' high awareness of fruits and vegetables' beneficial health effects, the influence of consumers' knowledge only is not sufficient to trigger behavioral changes. Consumers' intentions and behavior should be influenced indirectly, by changing their attitudes and subjective norms. All custom-made activities promoting a higher fruit and vegetable intake should consider the present findings to achieve a bigger effect on behavioral changes among consumers.

Modeling fruit and vegetable consumption in Serbia

Although regular intake of fruits and vegetables has an essential role in a healthy diet and well-being, a majority of consumers in Serbia have a suboptimal intake of these groceries. To understand the main determinants of this unsatisfactory situation, the study tested an extended model of the theory of planned behavior intending to suggest necessary steps for improving fruits and vegetables daily intake. This theory, extended for the role of knowledge, was tested using structural equation modeling. Fit indices confirmed the utility of this extended model of the theory of planned behavior in explaining consumers' behavior as well as the mediating role of behavioral intentions. Serbia, as one of the central developing countries in the Balkans, was chosen to test the model with the possibility of applying it to other developing countries facing malnutrition. Data were collected in North Serbia, through an online survey (n=688). Despite consumers' high awareness of fruits and vegetables' beneficial health effects, the influence of consumers' knowledge only is not sufficient to trigger behavioral changes. Consumers' intentions and behavior should be influenced indirectly, by changing their attitudes and subjective norms. All custom-made activities promoting a higher fruit and vegetable intake should consider the present findings to achieve a bigger effect on behavioral changes among consumers.

The application of the theory of planned behavior to nutritional behaviors related to cardiovascular disease among the women

BACKGROUND

Nutritional factors have been identified as preventable risk factors for cardiovascular disease; this study aimed to investigate the application of the Theory of Planned Behavior (TPB) in nutritional behaviors related to cardiovascular diseases among the women in Fasa city, Fars province, Iran.

METHODS

The study was conducted in two stages. First, the factors affecting nutritional behaviors associated with cardiovascular disease on 350 women who were referred to Fasa urban health centers were determined based on the TPB. In the second stage, based on the results of a cross-sectional study, quasi-expeimental study was performed on 200 women covered by Fasa health centers. The questionnaire used for the study was a questionnaire based on TPB. The questionnaire was completed by the experimental and control groups before and three months after the intervention. Data were analyzed by SPSS software using logistic regression, paired t-test, independent sample t-test, and chi-square test. The level of significance is considered 0.05.

RESULT

The constructs of attitude, subjective norms, and perceived behavioral control (PBC) were predictors of nutritional behaviors associated with cardiovascular disease in women. The constructs predicted 41.6% of the behavior. The results showed that mean scores of attitude, subjective norms, PBC, intention, nutritional performance related to the cardiovascular disease before intervention were, respectively, 24.32, 14.20, 18.10, 13.37 and 16.28, and after the intervention, were, respectively, 42.32, 25.40, 33.72, 30.13 and 41.38. All the constructs except the attitude in the intervention group were significantly higher (p < 0.001) than the control group.

CONCLUSION

The results of the present study showed that the educational intervention based on the TPB would be consider an effective educational and promotinal strategy for the nutritional behaviors to prevent cardiovascular disease in women. Considering the role of mothers in providing family food baskets and the effect of their nutritional behaviors on family members, the education of this group can promote healthy eating behaviors in the community and family.

Trends in the Number of Behavioural Theory-Based Healthy Eating Interventions Inclusive of Dietitians/Nutritionists in 2000-2020

Nutrition interventions developed using behaviour theory may be more effective than those without theoretical underpinnings. This study aimed to document the number of theory-based healthy eating interventions, the involvement of dietitians/nutritionists and the behaviour theories employed from 2000 to 2020. We conducted a review of publications related to healthy eating interventions that used behaviour change theories. Interventional studies published in English between 2000 and 2020 were retrieved from searching Medline, Cinahl, Embase, Psycinfo and Cochrane Central. Citation, country of origin, presence or absence of dietitian/nutritionist authors, participants, dietary behaviours, outcomes, theories and any behaviour change techniques (BCTs) stated were extracted. The publication trends on a yearly basis were recorded. A total of 266 articles were included. The number of theory-based interventions increased over the two decades. The number of studies conducted by dietitians/nutritionists increased, but since 2012, increases have been driven by other researchers. Social cognitive theory was the most used behaviour theory. Dietitians/nutritionists contributed to growth in publication of theory-based healthy eating interventions, but the proportion of researchers from other professions engaged in this field increased markedly. The reasons for this growth in publications from other professions is unknown but conjectured to result from greater prominence of dietary behaviours within the context of an obesity epidemic.

Habit is the Bridge between Intention and Behavior: A Look at Fruit and Vegetable Consumption among Low-Income Older Adults

OBJECTIVE

To examine the influence of habit and theory of planned behavior (TPB) variables in predicting low-income older adults' fruit and vegetable (F&V) consumption.

DESIGN

Cross-sectional study.

SETTING

A city in the southeast United States.

PARTICIPANTS

A total of 372 low-income older adults participated in this study.

RESULTS

Participants completed a validated survey measuring TPB variables (attitude, subjective norm, perceived behavioral control, and intention), F&V intake using the Block Dietary Fruit-Vegetable Screener, and self-reported habit index to measure F&V consumption. Perceived behavioral control was the largest factor influencing intention to consume F&V, followed by attitude and subjective norm. In addition, there was a significant interaction between habit strength and intention, such that intention influenced F&V consumption only among individuals with average or higher habit strength.

CONCLUSIONS

Findings from this study suggest health promotion programs aimed at increasing F&V intake among low-income older adults should focus on establishing F&V intake as a habit so that an individual's intentions to consume F&V can be transformed into actual F&V intake. Also, emphasizing how to overcome potential barriers would improve low-income older adults' actual F&V intake by increasing their sense of control over consuming F&V.

A Systematic Review of Psychosocial Nutrition Interventions for Young Adults

INTRODUCTION

Few have examined the effects of psychosocial nutrition interventions targeting young adults, a population with low fruit and vegetable (FV) consumption. This study investigated the impact of nutrition interventions with psychosocial content on improving young adult FV intake.

METHOD

This registered systematic review was guided by the Preferred Reported Items for Systematic Reviews and Meta-Analyses.

RESULTS

Searches on CINAHL, Embase, Medline PubMed, Ovid-Medline, PsychInfo, and Web of Science identified 4,113 records. Twenty-four randomized controlled trials were extracted. Eighteen studies found significant between-group differences in fruit and/or vegetable intake. Young adults with low income and racial-ethnic subgroups were underrepresented. A typology emerged as an organizing framework from the psychosocial intervention content. Interventions were anticipatory, socially engaged, a hybrid (anticipatory and socially engaged), or exposure-based. Studies also reported unintended consequences.

DISCUSSION

Significant between-group differences were mostly reported by anticipatory, socially engaged, or hybrid interventions, aligning with young adult developmental needs through detailed planning, goal-setting tasks, and/or addressing social norms. Interventions with insignificant differences lacked engagement and adequate exposure.

IMPLICATIONS FOR RESEARCH AND PRACTICE

Demographically inclusive studies are imperative in addressing dietary disparities by socioeconomic status. A typology of interventions emphasizing content rather than theories or treatment strategies widens opportunities for interdisciplinary collaboration. More research is needed to mitigate unintended consequences (boomerang effects) in which FV intake decreased postintervention or participants disengaged in activities intended to increase FV intake.

Recruiting and retaining young adults: what can we learn from behavioural interventions targeting nutrition, physical activity and/or obesity? A systematic review of the literature

OBJECTIVE

To describe strategies used to recruit and retain young adults in nutrition, physical activity and/or obesity intervention studies, and quantify the success and efficiency of these strategies.

DESIGN

A systematic review was conducted. The search included six electronic databases to identify randomised controlled trials (RCT) published up to 6 December 2019 that evaluated nutrition, physical activity and/or obesity interventions in young adults (17-35 years). Recruitment was considered successful if the pre-determined sample size goal was met. Retention was considered acceptable if ≥80 % retained for ≤6-month follow-up or ≥70 % for >6-month follow-up.

RESULTS

From 21 582 manuscripts identified, 107 RCT were included. Universities were the most common recruitment setting used in eighty-four studies (79 %). Less than half (46 %) of the studies provided sufficient information to evaluate whether individual recruitment strategies met sample size goals, with 77 % successfully achieving recruitment targets. Reporting for retention was slightly better with 69 % of studies providing sufficient information to determine whether individual retention strategies achieved adequate retention rates. Of these, 65 % had adequate retention.

CONCLUSIONS

This review highlights poor reporting of recruitment and retention information across trials. Findings may not be applicable outside a university setting. Guidance on how to improve reporting practices to optimise recruitment and retention strategies within young adults could assist researchers in improving outcomes.

Fruit and Vegetable Knowledge and Intake within an Australian Population: The AusDiab Study

Understanding the relationship between fruit and vegetable knowledge (FVK) and fruit and vegetable intake (FVI) is an important consideration for improved public health and successful targeting of health promotion messaging. The aim of this study was to investigate the association between FVK and FVI in Australian adults and to identify subgroups most at risk of poor knowledge. Using data from the Australian Diabetes, Obesity, and Lifestyle Study (AusDiab), we investigated associations between FVK and FVI, as well as demographic and lifestyle factors. Baseline FVK was measured using two self-reported questions. FVI was assessed using a validated, self-reported, food frequency questionnaire in 1999/00 (baseline), 2004/05, and 2011/12. Amongst the 8966 participants assessed at baseline, 24.1% had adequate, 73.0% had insufficient, and 2.9% had poor FVK. Using linear regression, those with insufficient or poor FVK reported significantly lower FVI (grams/day) compared to those with adequate FVK: baseline (coefficient (95%CI)): −67.1 (−80.0, −54.3) and −124.0 (−142.9, −105.1), respectively, whilst, at 12 years, the differences were −42.5 (−54.6, −30.5) and −94.6 (−133.8, −55.5) grams/day, respectively (all p < 0.001). Poor FVK was more likely to be reported in males, older individuals (>65 years), socio-economically disadvantaged, smokers, and those with insufficient physical activity/sedentary behavior. We demonstrate that having adequate knowledge of FVI, defined as knowing to consume fruit and vegetables several times a day for a well-balanced diet, is strongly associated with FVI, with several demographic and lifestyle factors predicting FVK. Health promotion messages aimed at increasing FVK should target these subgroups for maximal effect.

Effectiveness of gender-targeted versus gender-neutral interventions aimed at improving dietary intake, physical activity and/or overweight/obesity in young adults (aged 17-35 years): a systematic review and meta-analysis

BACKGROUND

Young adulthood has become synonymous with the development of poor lifestyle behaviours associated with an increased risk of preventable chronic disease in later years. Interventions aiming to improve health behaviours may be more engaging and effective if they are targeted to males or females than interventions with a gender-neutral approach. This review will examine the outcome effectiveness of gender-targeted and gender-neutral interventions targeting nutrition, physical activity or overweight/obesity in young adults (17-35 years).

METHODS

Six electronic databases were searched for randomised controlled trials (RCTs) published up to December 2019 that evaluated nutrition, physical activity and/or overweight/obesity interventions in young adults (17-35 years). An effective intervention was one where the change in one or more primary outcome was positive and statistically significantly different from baseline, compared with control, or if no control comparator, compared with another active intervention. Effectiveness of outcomes was compared between gender-targeted and gender-neutral studies.

RESULTS

In total 21,582 manuscripts were identified and 107 RCTs were included; 30 gender-targeted studies (28%) and 77 gender-neutral (72%). Most gender-targeted studies were female targeted (n = 22, 73%). Primary outcome/s were adiposity (n = 36, 34%), nutrition (n = 29, 27%), physical activity (n = 28, 26%), or a combination of (n = 14, 14%). A greater proportion of gender-targeted than gender-neutral studies were effective in improving nutrition (n = 6, 100% and n = 17, 74% of studies respectively) and physical activity outcomes (n = 6, 86% and n = 14, 67% respectively), where as a greater proportion of gender-neutral studies were effective in improving adiposity outcomes (n = 13, 59% and n = 5, 36% respectively). None of these differences were statistically significant. Meta-analyses for weight found no significant differences between gender-targeted and gender-neutral studies for weight loss or weight gain prevention studies. Meta-analysis for fruit and vegetable intake demonstrated a significantly greater increase in intervention participants in gender-targeted studies of +158 g/day for > 3 months.

CONCLUSIONS

Although differences in outcome effectiveness were identified between gender-targeted and gender-neutral studies, these were not significantly different. This is likely due to an insufficient number of studies to detect a difference. The meta-analysis for fruit and vegetable intake findings should be interpreted with caution due to including only two gender-targeted studies. The findings collectively are suggestive of a potential difference requiring further investigation. To truly determine the effectiveness of gender-targeted interventions, well-designed RCTs comparing gender-targeted interventions with gender-neutral and control are needed.

REGISTRATION

This systematic review is a secondary analysis of studies included in a systematic review examining the effectiveness of interventions targeting nutrition, physical activity, or overweight/obesity in young adults, for which a predefined protocol was registered with PROSPERO (CRD42017075795).

Effects of interventions based on the theory of planned behavior on sugar-sweetened beverage consumption intentions and behavior

There is increasing concern about the health risks of added dietary sugar, perhaps particularly when consumed in beverages that contain no essential nutrients (e.g., sodas). The purpose of this experiment was to examine the relative and combined efficacy of three interventions based on the theory of planned behavior (TPB) for motivating reductions in sugar sweetened beverage (SSB) consumption. Four-hundred-thirty undergraduates were randomised in a 2*2*2 factorial design. Participants received either information designed to increase awareness of the risks of SSB consumption or control information, and received either information about SSB consumption norms or no norms information, and either made plans to reduce their SSB consumption or engaged in a control planning task. Results demonstrated that the interventions, separately and in conjunction, resulted in greater intentions to reduce SSB consumption in the future, and there was evidence that these effects were mediated by the effects the interventions had on the TPB constructs. Further, the risks information resulted in more behaviors indicative of preparations to alter SSB consumption and those who engaged in the SSB planning task reported significantly lower SSB consumption at follow-up compared to controls. The three interventions utilized showed promise for altering SSB consumption intentions and behavior and, given their brevity and low cost, have potential to be developed into large scale community-based interventions that may lead to meaningful public health benefits.

Effectiveness of Interventions and Behaviour Change Techniques for Improving Dietary Intake in Young Adults: A Systematic Review and Meta-Analysis of RCTs

Poor eating habits are common during young adulthood and influence chronic disease morbidity. This systematic review evaluates the effectiveness of interventions aiming to improve dietary intake among young adults and, identifies which behaviour change techniques (BCTs) are most effective. Six electronic databases were searched for RCTs published until October 2018, and evaluating behavioural interventions assessing change in dietary intake in young adults (17–35 years). Of the 18,779 articles identified, 54 were included. Forty studies focused on fruit and/or vegetable intake, of which 63% showed a significant between-group difference in favour of the intervention group. Meta-analysis (n = 17) demonstrated a significant increase in fruit and vegetable intake of +68.6 g/day after three months of intervention and +65.8 g/day for interventions >3 months when compared to control. A meta-analysis (n = 5) on total energy intake found no significant differences between groups. The BCTs with the highest effectiveness ratio were habit formation (100%), salience of consequences (83%) and adding objects to the environment (70%). The review highlights the potential of behavioural interventions to improve young adults’ fruit and vegetable intake but was less convincing for other dietary outcomes. Due to the lack of studies including each BCT, the BCTs imperative to success could not be identified.

Multilevel Structural Equation Modeling of Students' Dietary Intentions/Behaviors, BMI, and the Healthfulness of Convenience Stores

Background: When dietary behaviors are habitual, intentions are low, and environmental cues, such as the consumer food environment, might guide behavior. How might intentions to eat healthily and ultimately actual dietary behaviors, be influenced by the consumer food environment (including the availability and affordability of healthy foods) in convenience stores? This study will determine pathways between the healthfulness of convenience stores and college students’ dietary intentions/behaviors, and body mass index (BMI). Methods: Through multilevel structural equation modeling, a comparison was made of students’ healthful meal intentions (HMI); intake (fruits/vegetables, %kcal/fat, sugar-sweetened beverages (SSBs) and whole-grains); and measured BMI; as well as the healthfulness of convenience stores (fruits/vegetables availability/quality, healthy food availability/affordability). Data was collected on 1401 students and 41 convenience stores across 13 US college campuses. Results: Controlling for gender, HMI was negatively associated with SSBs (β = −0.859) and %kcal/fat (β = −1.057) and positively with whole-grains (β = 0.186) and fruits/vegetables intake (β = 0.267); %Kcal/fat was positively (β = 0.098) and fruits/vegetables intake (β = −0.055) negatively associated with BMI. Campus level, fruits/vegetables availability were positively associated to HMI (β = 0.214, β = 0.129) and directly/negatively to BMI (β = −2.657, β = −1.124). Conclusions: HMI modifies dietary behaviors, with energy from fat and fruit/vegetable intake the most predictive of weight. Availability of fruit/vegetables in convenience stores make it easier for young adults to eat well.

Determinants of choice of delivery place: Testing rational choice theory and habitus theory

OBJECTIVE

The current study uses two antipodal social science theories, the rational choice theory and the habitus theory, and applies these to describe how women choose between intraclinical (i.e., hospital-run birth clinics) and extraclinical (i.e., midwife-led birth centres or home births) delivery places.

DESIGN, SETTING, PARTICIPANTS, MEASUREMENTS

Data were collected in a cross-sectional questionnaire-based survey among 189 women. A list of 22 determinants, conceptualized to capture the two theoretical concepts, were rated on a 7-point Likert scale with 1 = unimportant to 7 = very important. The analytic method was structural equation modelling. A model was built, in which the rational choice theory and the habitus theory as latent variables predicted the choice of delivery place.

FINDINGS

With regards to the choice of delivery place, 89.3% of the women wanted an intraclinical and 10.7% an extraclinical delivery place at the time of their last child's birth. Significant differences between women with a choice of an intraclinical or extraclinical delivery place were found for 14 of the 22 determinants. In the structural equation model, rational choice theory determinants predicted a choice of intraclinical delivery and habitus theory determinants predicted a choice of extraclinical delivery.

KEY CONCLUSIONS

The two theories had diametrically opposed effects on the choice of delivery place. Women are more likely to decide on intraclinical delivery when arguments such as high medical standards, positive evaluations, or good advanced information are rated important. In contrast, women are more likely to decide on extraclinical delivery when factors such as family atmosphere during birth, friendliness of health care professionals, or consideration of the woman's interests are deemed important.

IMPLICATIONS FOR PRACTICE

A practical implication of our study is that intraclinical deliveries may be promoted by providing comprehensive information, data and facts on various delivery-related issues, while extraclinical deliveries may be fostered by healthcare professionals tailoring personal or social beliefs, attitudes and opinions. Our study advocates that legislation and policy- and decision-makers should support different delivery place options in order to accommodate the choices and preferences of different women. The study demonstrates the usefulness of theory for describing and explaining a complex decision-making process, here the choice of delivery place.

Reduction in Vegetable Intake Disparities With a Web-Based Nutrition Education Intervention Among Lower-Income Adults in Japan: Randomized Controlled Trial

BACKGROUND

No existing Web-based nutrition education interventions have been evaluated in light of socioeconomic status just in Japan.

OBJECTIVE

The aim was to investigate the effect of a Web-based intervention program on reducing vegetable intake disparities between low- and middle-income Japanese adults.

METHODS

In this randomized controlled trial, participants were assessed at three time points-baseline, postintervention (5 weeks later), and a follow-up after 3 months-from October 2015 to March 2016. We collected data via a Japanese online research service company from 8564 adults aged 30 to 59 years. Participants were stratified according to national population statistics for gender and age, and randomly selected. They were then randomly allocated into intervention (n=900) and control (n=600) groups such that both groups contained an equal number of individuals with low and middle income. The intervention program encouraged behavior change using behavioral theories and techniques tailored to their assumed stage of change. The outcome was vegetable intake servings per day (1 serving being approximately 70 g).

RESULTS

Out of 900 participants who started, 450 were from the middle income group (of which 386 or 85.7% completed the intervention), and 450 were from the low income group (of which 371 or 82.4% completed). In the intervention group, vegetable intake increased in the low-income participants from baseline to postintervention (0.42 servings, 95% CI 0.11-0.72). A two-way analysis of variance showed that low-income participants had significant main effects of group (η2=0.04, P=.01) and time (η2=0.01, P<.001), and a significant interaction (η2=0.01, P=.009). Middle-income participants also had a significant main effect of time (η2=0.01, P=.006) and a significant interaction (η2=0.01, P=.046).

CONCLUSIONS

This Web-based nutritional education intervention could fill the vegetable intake gap between low- and middle-income adults in Japan, and is expected to prevent noncommunicable and lifestyle-related diseases. Further intervention program improvements are necessary to maintain and increase vegetable intake for other groups.

TRIAL REGISTRATION

Current Controlled Trials (UMIN-ICDR): UMIN000019376; https://upload.umin.ac.jp/cgi-open-bin/ icdr_e/ctr_view.cgi?recptno=R000022404 (Archived by WebCite at http://www.webcitation.org/6u9wihBZU).

The Theory of Planned Behavior and Physical Activity Change: Outcomes of the Aging Well and Healthily Intervention Program for Older Adults

The predictive value of the Theory of Planned Behavior (TPB) on intention and physical activity (PA) over time was examined. Data from the Aging Well and Healthily intervention program (targeting perceived behavioral control and attitude, not subjective norm) were analyzed, including pretest (T0), posttest (T1, except subjective norm) and 4-6 months follow-up (T2, PA outcomes only) (N = 387, M age 72 years). Structural equation modeling was used to test a TPB model. PA was measured subjectively using the Voorrips sports subscale (T0 and T2), items measured perceived increase in PA (T1), and adherence to exercises (T1 and T2). Model fit was good. The TPB explained variation in intention well (R² .54-.60) and some PA behavior (R² .13-.16). The intervention successfully got participants to exercise independent of the measured TPB concepts. More TPB studies in the context of interventions are needed.

Evaluation of a Theory-Based Intervention Aimed at Reducing Intention to Use Restrictive Dietary Behaviors Among Adolescent Female Athletes

OBJECTIVE

To evaluate the effectiveness of a theory-based intervention to reduce the intention to use restrictive dietary behaviors for losing weight among adolescent female athletes involved in aesthetic sports.

DESIGN

Cluster-randomized controlled trial.

SETTING

Aesthetic sport teams of adolescent female athletes aged 12-17 years.

PARTICIPANTS

Two teams (n = 37 athletes) in the intervention group and 3 teams (n = 33) in the comparison group.

INTERVENTIONS

The 2 groups received nutrition education during 3 weekly 60-minute sessions. The intervention group was further exposed to a theory-based intervention targeting the specific determinant of intention to use restrictive dietary behaviors for losing weight, namely attitude.

MAIN OUTCOME MEASURES

Difference over time between groups in intention to use restrictive dietary behaviors for losing weight and in nutrition knowledge.

ANALYSIS

Mixed models for repeated measures.

RESULTS

The theory-based intervention contributed to maintaining a low intention of using restrictive dietary behaviors for losing weight over time in the intervention group compared with the comparison group (P < .03). Nutrition knowledge score increased equally in both groups.

CONCLUSION AND IMPLICATIONS

Complementing nutrition education with theory-based behavior change intervention may help maintain a low intention of using restrictive dietary behaviors for losing weight among female high school athletes involved in aesthetic sports.

A systematic review of eHealth behavioral interventions targeting smoking, nutrition, alcohol, physical activity and/or obesity for young adults

A systematic review of randomized control trials (RCT) was undertaken to evaluate the effectiveness of eHealth behavioral interventions aiming to improve smoking rates, nutrition behaviors, alcohol intake, physical activity levels and/or obesity (SNAPO) in young adults. Seven electronic databases were searched for RCTs published in English from 2000 to April 2015 and evaluating eHealth interventions aiming to change one or multiple SNAPO outcomes, and including young adult (18-35years) participants. Of 2,159 articles identified, 45 studies met the inclusion criteria. Most interventions targeted alcohol (n=26), followed by smoking (n=7), physical activity (n=4), obesity (n=4) and nutrition (n=1). Three interventions targeted multiple behaviors. The eHealth interventions were most often delivered via websites (79.5%). Most studies (n=32) compared eHealth interventions to a control group (e.g. waiting list control, minimal intervention), with the majority (n=23) showing a positive effect on a SNAPO outcome at follow-up. Meta-analysis demonstrated a significantly lower mean number of drinks consumed/week in brief web or computer-based interventions compared to controls (Mean Difference -2.43 [-3.54, -1.32], P<0.0001, n=10). Sixteen studies compared eHealth delivery modes, with inconsistent results across target behaviors and technology types. Nine studies compared eHealth to other modes of delivery (e.g. in person) with all finding no difference in SNAPO outcomes between groups at follow-up. This review provides some evidence for the efficacy of eHealth SNAPO interventions for young adults, particularly in the short-term and for alcohol interventions. But there is insufficient evidence for their efficacy in the longer-term, as well as which mode of delivery is most effective.

Household, psychosocial, and individual-level factors associated with fruit, vegetable, and fiber intake among low-income urban African American youth

BACKGROUND

Childhood obesity, one of the greatest challenges to public health, disproportionately affects low-income urban minority populations. Fruits and vegetables (FV) are nutrient dense foods that may be inversely associated with excessive weight gain. We aimed to identify the individual characteristic, psychosocial, and household factors influencing FV and fiber consumption in low-income African-American (AA) youth in Baltimore, MD.

METHODS

Cross-sectional analysis of data collected from 285 low-income AA caregiver-youth (age range: 10-14 y) dyads participating in the baseline evaluation of the B'More Healthy Communities for Kids obesity prevention trial. The Kid's Block FFQ was used to estimate daily intakes of FV (including 100 % fruit juice) and dietary fiber. Questionnaires were used to assess household socio-demographics, caregiver and youth food purchasing and preparation behavior, and youth psychosocial information. Ordered logit regression analyses were conducted to examine psychosocial and food-related behavior associated with FV and dietary fiber intake (quartile of intake) controlling for youth age, sex, BMI percentile, total calorie intake and household income.

RESULTS

On average, youth consumed 1.5 ± 1.1 (M ± SD) servings of fruit, 1.8 ± 1.7 serving of vegetables, and 15.3 ± 10.9 g of fiber/day. There were no differences by gender, age or household income. Greater youth's healthy eating intentions and self-efficacy scores were associated with greater odds ratio for higher intake of FV and fiber (Intention: ORfruit 1.22; 95 % CI: 1.06-1.41, ORvegetable 1.31; 1.15-1.51 and ORfiber 1.46; 1.23-1.74, Self-efficacy: ORfruit 1.07; 1.03-1.12, ORvegetable 1.04; 1.01-1.09, ORfiber 1.10; 1.04-1.16). Youth receiving free/low-cost breakfast were more than twice as likely to have higher fiber intake than those who did not receive free breakfast (OR 2.7; 1.10; 6.9). In addition, youth shopping more frequently at supermarkets were more likely to have greater vegetable and fiber intake (OR 1.26; 1.06-1.50; OR 1.28; 1.03-1.58, respectively). Also, youth with parents who shopped more frequently at fast-food stores had 7 % lower odds for higher vegetable intake (95 % CI: 0.88-0.99).

CONCLUSION

In this study, both, youth and household factors were associated with youth FV and fiber intake, underscoring the need for a multi-level approach to increasing youths' diet quality. These results will inform and shape an effective intervention program for improving youth dietary intakes.

How Effective are Behavior Change Interventions Based on the Theory of Planned Behavior?

Abstract. The theory of planned behavior (TPB) is a prominent framework for predicting and explaining behavior in a variety of domains. The theory is also increasingly being used as a framework for conducting behavior change interventions. In this meta-analysis, we identified 82 papers reporting results of 123 interventions in a variety of disciplines. Our analysis confirmed the effectiveness of TPB-based interventions, with a mean effect size of .50 for changes in behavior and effect sizes ranging from .14 to .68 for changes in antecedent variables (behavioral, normative, and control beliefs, attitude, subjective norm, perceived behavioral control, and intention). Further analyses revealed that the interventions’ effectiveness varied for the diverse behavior change methods. In addition, interventions conducted in public and with groups were more successful than interventions in private locations or focusing on individuals. Finally, we identified gender and education as well as behavioral domain as moderators of the interventions’ effectiveness.

Efficacy and External Validity of Electronic and Mobile Phone-Based Interventions Promoting Vegetable Intake in Young Adults: Systematic Review and Meta-Analysis

Background

Young adults (18–35 years) remain among the lowest vegetable consumers in many western countries. The digital era offers opportunities to engage this age group in interventions in new and appealing ways.

Objective

This systematic review evaluated the efficacy and external validity of electronic (eHealth) and mobile phone (mHealth) -based interventions that promote vegetable intake in young adults.

Methods

We searched several electronic databases for studies published between 1990 and 2015, and 2 independent authors reviewed the quality and risk of bias of the eligible papers and extracted data for analyses. The primary outcome of interest was the change in vegetable intake postintervention. Where possible, we calculated effect sizes (Cohen d and 95% CIs) for comparison. A random effects model was applied to the data for meta-analysis. Reach and representativeness of participants, intervention implementation, and program maintenance were assessed to establish external validity. Published validation studies were consulted to determine the validity of tools used to measure intake. We applied the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system to evaluate the overall quality of the body of evidence.

Results

Of the 14 studies that met the selection criteria, we included 12 in the meta-analysis. In the meta-analysis, 7 studies found positive effects postintervention for fruit and vegetable intake, Cohen d 0.14–0.56 (pooled effect size 0.22, 95% CI 0.11–0.33, I²=68.5%, P=.002), and 4 recorded positive effects on vegetable intake alone, Cohen d 0.11–0.40 (pooled effect size 0.15, 95% CI 0.04–0.28, I²=31.4%, P=.2). These findings should be interpreted with caution due to variability in intervention design and outcome measures. With the majority of outcomes documented as a change in combined fruit and vegetable intake, it was difficult to determine intervention effects on vegetable consumption specifically. Measurement of intake was most commonly by self-report, with 5 studies using nonvalidated tools. Longer-term follow-up was lacking from most studies (n=12). Risk of bias was high among the included studies, and the overall body of evidence was rated as low quality. The applicability of interventions to the broader young adult community was unclear due to poor description of external validity components.

Conclusions

Preliminary evidence suggests that eHealth and mHealth strategies may be effective in improving vegetable intake in young adults; whether these small effects have clinical or nutritional significance remains questionable. With studies predominantly reporting outcomes as fruit and vegetable intake combined, we suggest that interventions report vegetables separately. Furthermore, to confidently establish the efficacy of these strategies, better-quality interventions are needed for young adults, using valid measures of intake, with improved reporting on costs, sustainability and long-term effects of programs.

Trial registration

PROSPERO International Prospective Register of Systematic Reviews: CRD42015017763; http://www.crd.york.ac.uk/PROSPERO/display_record.asp?ID=CRD42015017763 (Archived by WebCite at http://www.webcitation.org/6fLhMgUP4)

Explaining Vegetable Consumption among Young Adults: An Application of the Theory of Planned Behaviour

Although fruit and vegetable consumption is highly recommended for a healthy and balanced daily diet, several European countries do not meet these recommendations. In Italy, only 45% of young people are consuming at least one portion of vegetables per day. Therefore, this paper aims to understand the main determinants of vegetables consumption among young adults to suggest possible intervention strategies. A cross-sectional study was conducted on a samples of Italian students (n = 751), using the theory of planned behaviour (TPB) as a conceptual framework. A structural equation model (SEM) was developed to test the TPB predictors for vegetable consumption, and the role of background factors (socio-demographic and personal characteristics) in improving the TPB model’s explaining power. Overall, 81% and 68%, respectively, of intentions and behaviour variance is explained by the TPB model. Socio-demographic and personal characteristics were found to influence intentions and behaviour indirectly by their effects on the theory’s more proximal determinants. Interventions should be targeted to improve perceived behavioural control (PBC), attitudes and subjective norms that significantly affect intentions. Tailored interventions for male students, enrolled in courses other than food science, and doing less physical activity may have a larger effect on behavioural change.

Factors associated with nutrition label use among female college students applying the theory of planned behavior

BACKGROUND/OBJECTIVES

Use of nutrition labels in food selection is recommended for consumers. The aim of this study is to examine factors, mainly beliefs explaining nutrition label use in female college students based on the Theory of Planned Behavior (TPB).

SUBJECTS/METHODS

The subjects were female college students from a university in Seoul, Korea. The survey questionnaire was composed of items examining general characteristics, nutrition label use, behavioral beliefs, normative beliefs, corresponding motivation to comply, and control beliefs. The subjects (n = 300) responded to the questionnaire by self-report, and data from 275 students were analyzed using t-test or χ²-test.

RESULTS

The results showed that 37.8% of subjects were nutrition label users. Three out of 15 behavioral beliefs differed significantly by nutrition label use. Nutrition label users agreed more strongly on the benefits of using nutrition labels including 'comparing and selecting better foods' (P < 0.001), 'selecting healthy foods' (P < 0.05). The negative belief of 'annoying' was stronger in non-users than in users (P < 0.001). Three out of 7 sources (parents, siblings, best friend) were important in nutrition label use. Twelve out of 15 control beliefs differed significantly by nutrition label use. These included beliefs regarding constraints of using nutrition labels (e.g., time, spending money for healthy foods) and lack of nutrition knowledge (P < 0.001). Perceived confidence in understanding and applying the specifics of nutrition labels in food selection was also significantly related to nutrition label use (P < 0.001).

CONCLUSIONS

This study found that the beliefs, especially control beliefs, suggested in the TPB were important in explaining nutrition label use. To promote nutrition label use, nutrition education might focus on increasing perceived control over constraints of using nutrition labels, acquiring skills for checking nutrition labels, as well as the benefits of using nutrition labels and receiving support from significant others for nutrition label use.

Factors affecting acceptability of an email-based intervention to increase fruit and vegetable consumption

BACKGROUND

Fresh Facts is a 30-day email-delivered intervention designed to increase the fruit and vegetable consumption of Australian young adults. This study investigated the extent to which the program was acceptable to members of the target audience and examined the relationships between participant and intervention characteristics, attrition, effectiveness, and acceptability ratings.

METHODS

Young adults were randomised to two levels of message frequency: high-frequency (n = 102), low-frequency (n = 173). Individuals in the high-frequency group received daily emails while individuals in the low-frequency group received an email every 3 days.

RESULTS

Individuals in the high-frequency group were more likely to indicate that they received too many emails than individuals in the low-frequency group. No other differences in acceptability were observed. Baseline beliefs about fruit and vegetables were an important predictor of intervention acceptability. In turn, acceptability was associated with a number of indicators of intervention success, including change in fruit and vegetable consumption.

CONCLUSIONS

The findings highlight the importance of considering the relationship between these intervention and participant factors and acceptability in intervention design and evaluation. Results support the ongoing use of email-based interventions to target fruit and vegetable consumption within young adults. However, the relationships between beliefs about fruit and vegetable consumption and acceptability suggest that this intervention may be differentially effective depending on individual's existing beliefs about fruit and vegetable consumption. As such, there is a pressing need to consider these factors in future research in order to minimize attrition and maximize intervention effectiveness when interventions are implemented outside of a research context.