Monetary Incentive Interventions Can Enhance Psychological Factors Related to Fruit and Vegetable Consumption

Effect of a pragmatic lifestyle modification intervention on physical activity levels and body mass index among obese and overweight adolescents in Udupi, India: a cluster randomized trial

Background

Determine the effects of a multifactorial lifestyle intervention on physical activity (PA), BMI and health-related quality of life (QoL) in obese and overweight adolescents.

Methods

Nine schools in India were clustered randomly in a 12-month study with students allocated to a multifactorial intervention (MFI), or exercise only (EX) or control (CON) group. Participants were adolescents aged 11-16 years (n=671). In the MFI group, adolescents and their parents received lifestyle education using a validated booklet combined with a PA intervention for school students. The EX group received school-based PA only; the CON group continued regular activities. Primary outcomes were PA levels measured with the PAQ-A, and BMI; the secondary outcome was health-related QoL. A linear regression statistical model was used to analyse time, group effects and interactions, with Bonferroni correction for within-group differences at baseline (T0) and at 12-weeks (T1) (post-intervention), 6-month (T2) and 12-month (T3) follow-ups.

Results

Significant time and group effects observed for all groups with PA scores (p<0.001), with MFI group having largest increase in PA; with BMI (p<0.001) and MFI showing the least gain in BMI; and HRQOL (p<0.001), with MFI group showing greatest improvement in scores. There were significant increases in PA at T1 and T3 time-points with the EX group, and at T3 time-point only for MFI and CON, with MFI group showing largest increase in HRQOL scores. BMI increased significantly for all groups at T2 (MFI p=0.001, EX p<0.001) and T3 (p<0.001), while HRQOL increased significantly for both MFI and EX at both follow-ups (p<0.001).

Conclusions

School-based lifestyle MFI was more effective for improving PA, lifestyle behaviours and HRQOL than exercise alone for adolescents, although BMI was not reduced. MFI with PA could be an effective school-based approach for behaviour modification but BMI has limitations for measuring body composition changes.

Registration

CTRI/2019/04/018834 (30/04/2019).

The Impact of Monetary Incentives on Delay Discounting Within a Year-Long Physical Activity Intervention

BACKGROUND

Delay discounting is the depreciation in a reward's perceived value as a function of the time until receipt. Monetary incentive programs that provide rewards contingent on meeting daily physical activity (PA) goals may change participants' delay discounting preferences.

PURPOSE

Determine if monetary incentives provided in close temporal proximity to meeting PA goals changed delay discounting, and if such changes mediated intervention effects.

METHODS

Inactive adults (n = 512) wore accelerometers during a 12-month intervention where they received proximal monetary incentives for meeting daily moderate-to-vigorous PA (MVPA) goals or delayed incentives for study participation. Delay discount rate and average MVPA were assessed at baseline, end of intervention, and a 24-month follow-up. Using structural equation modeling, we tested effects of proximal versus delayed rewards on delay discounting and whether any changes mediated intervention effects on MVPA. PA self-efficacy was also evaluated as a potential mediator, and both self-efficacy and delay discounting were assessed as potential moderators of intervention effects.

RESULTS

Proximal rewards significantly increased participants' delay discounting (β = 0.238, confidence interval [CI]: -0.078, 0.380), indicating greater sensitivity to reinforcement timing. This change did not mediate incentive-associated increases in MVPA at the end of the 12-month intervention (β = -0.016, CI: -0.053, 0.019) or at a 24-month follow-up (β = -0.020, CI: -0.059, 0.018). Moderation effects were not found.

CONCLUSIONS

Incentive-induced increases in delay discounting did not deleteriously impact MVPA. This finding may help assuage concerns about using monetary incentives for PA promotion, but further research regarding the consequences of changes in delay discounting is warranted.

A daily diary investigation of cannabis use and its diet and exercise correlates

Background

The increasing availability of legal-market cannabis products has raised many questions about potential harms and benefits of increased use. In particular, concerns have been raised about the possible negative impact of cannabis use on behavioral determinants of obesity and chronic disease, including diet and exercise. However, previous research is mixed and has largely relied on cross-sectional survey data and coarse measurements of cannabis use, underscoring the need for more rigorous research designs.

Purpose

The present study utilized longitudinal daily diary data to assess whether exercise and diet patterns differed between cannabis users and non-users and, within cannabis users, whether legal-market cannabis use, diet, and exercise covaried within individuals across time and based on cannabinoid content.

Methods

A sample of 98 participants (77 cannabis users, 21 non-users) completed a baseline appointment and a 30-day daily diary study assessing their daily cannabis use, diet, and exercise. Cannabis users were quasi-randomly assigned to use either a THC-dominant flower product (n = 36) or a CBD-containing flower product (n = 41) ad libitum over the course of the daily diary study. Participants were between the ages of 21 and 41 (M = 29.28) and were majority male (61.2%).

Results

At baseline, there were no differences in BMI or exercise behavior between users and non-users. Likelihood of exercising and exercise minutes per day over the 30-day period also did not differ between users and non-users, nor did these outcomes differ on cannabis use vs. non-use days among cannabis using participants. In contrast, there was some evidence for a relationship between cannabis use and dietary measures. At baseline, non-users scored higher on the Healthy Eating Index than users. Daily data also indicated that users consumed marginally more salty snacks and fast food per day relative to non-users, and users consumed more fruits/vegetables and marginally more salty snacks on cannabis use days vs. non-use days. Interestingly, among users, no associations were dependent on the cannabinoid content of their assigned product.

Conclusion

Findings suggest little association between cannabis use and exercise but underscore the need for further research on how cannabis use may impact dietary patterns. Future research should examine the impact of cannabis on non-behavioral pathways to obesity and chronic disease (e.g., metabolism).

The backfiring effects of monetary and gift incentives on Covid-19 vaccination intentions

We provide evidence that material inducements for Covid-19 vaccination may backfire. Results from a hypothetical survey experiment in China (N = 1365) show incentives of 8-125 USD reduce vaccine uptake intentions compared to simply offering vaccination for free. Ours is the first Covid-19 vaccine study to separately consider and directly compare the effects of monetary and goods-based incentives, both of which have been widely employed by countries seeking to increase uptake; we demonstrate that both types backfire equally. Results are compared against the burgeoning literature on Covid-19 vaccine incentives.

Cooking Interventions for Improving Diet Quality Among Black Americans: A Randomized Controlled Trial

BACKGROUND

Non-Hispanic Black Americans experience the highest, and most rapidly increasing, rates of obesity. Despite evidence that this is at least somewhat related to poor diet quality, we have yet to identify effective interventions for improving diet quality long-term. Restrictive diets can be ineffective and often harmful. In contrast, there is a well-established connection between home cooking and lower body mass index, better diet quality, and improved health.

PURPOSE

The present study applied the Theory of Planned Behavior (TPB) to examine the effect of an intervention delivering cooking instruction, rather than nutrition information, on beliefs, attitudes, and behaviors pertaining to diet quality and cooking among Black adults in the USA.

METHODS

An online sample of Black Americans (N = 147), ages 18-76 (M = 30.69, SD = 10.42) were recruited via Prolific and randomized to view either a cooking tutorial video or a "standard of care" control webpage followed by either an implementation intentions (II) writing activity or a "freestyle" control writing activity. Cognitions and behavior related to healthy eating and cooking were measured at baseline, post-intervention, and 1-week follow-up.

RESULTS

Results of mixed-effects modeling indicated that participants randomized to the video condition reported significantly greater post-intervention intentions to cook (p < .001), which positively correlated with cooking behavior over the subsequent week (p < .01). There was no effect of the II intervention on subsequent-week behavior (ps > .413). Importantly, 75% (n = 105) indicated experiencing food insecurity at the time of data collection.

CONCLUSIONS

These results highlight a promising pathway for improving nutrition and diet-related health outcomes among Black Americans while highlighting that any intervention must account for food insecurity in this population.

Strategies to increase the intention to get vaccinated against COVID-19: Findings from a nationally representative survey of US adults, October 2020 to October 2021

OBJECTIVES

We examined COVID-19 vaccination status, intention, and hesitancy and the effects of five strategies to increase the willingness of unvaccinated adults (≥18 years) to get a COVID vaccine.

METHODS

Online surveys were conducted between October 1-17, 2020 (N = 14,946), December 4-16, 2020 (N = 15,229), April 8-22, 2021 (N = 14,557), June 17-July 6, 2021 (N = 30,857), and September 3-October 4, 2021 (N = 33,088) with an internet-based, non-probability opt-in sample of U.S. adults matching demographic quotas. Respondents were asked about current COVID-19 vaccination status, intention and hesitancy to get vaccinated, and reasons for vaccine hesitancy. Unvaccinated respondents were assigned to treatment groups to test the effect of five strategies (endorsements, changing social restrictions, financial incentives, vaccine requirements for certain activities, and vaccine requirements for work). Chi-square tests of independence were performed to detect differences in the response distributions.

RESULTS

Willingness to be vaccinated (defined as being vaccinated or planning to be) increased over time from 47.6 % in October 2020 to 81.1 % in October 2021. By October 2021, across most demographic groups, over 75 % of survey respondents had been or planned to be vaccinated. In terms of strategies: (1) endorsements had no positive effect, (2) relaxing the need for masks and social distancing increased Intention to Get Vaccinated (IGV) by 6.4 % (p < 0.01), (3) offering financial incentives increased the IGV between 12.3 and 18.9 % (p <.001), (4) vaccine requirements for attending sporting events or traveling increased IGV by 7.8 % and 9.1 %, respectively (p = 0.02), and vaccine requirement for work increased IGV by 35.4 %. The leading causes (not mutually exclusive) for hesitancy were concerns regarding vaccine safety (52.5 %) or side effects (51.6 %), trust in the government's motives (41.0 %), and concerns about vaccine effectiveness (37.6 %).

CONCLUSIONS

These findings suggest that multiple strategies may be effective and needed to increase COVID-19 vaccination among hesitant adults during the pandemic.

Count on trust: the indirect effect of trust in government on policy compliance with health behavior instructions

Trust in government is considered a prominent factor for enhancing public compliance with government policies and instructions. The Coronavirus pandemic demonstrates the crucial role public compliance with governmentally issued health guidelines has in mitigating the pandemic. However, the mechanism explaining the trust-compliance association, particularly in regard to health-behavior compliance, is unclear. This article develops a new theoretical model, the Mediated Trust Model (MTM), for explaining the relationship between trust in government and public compliance with health instructions. The model extends the classic Health Belief Model for predicting health behavior by claiming that the perceptions regarding the instructions' costs, benefits and one's ability to perform them are affected by trust in government and mediate the trust-compliance association. The MTM was tested in four cross-sectional studies performed during the first 20 months of the Coronavirus pandemic in Israel on 3732 participants, for various health instructions. Implications for public health literature, policy compliance theory and policy makers are discussed.

Payments and freedoms: Effects of monetary and legal incentives on COVID-19 vaccination intentions in Germany

Monetary and legal incentives have been proposed to promote COVID-19 vaccination uptake. To evaluate the suitability of incentives, an experiment with German participants examined the effects of payments (varied within subjects: 0 to 10,000 EUR) and freedoms (varied between subjects: vaccination leading vs. not leading to the same benefits as a negative test result) on the vaccination intentions of previously unvaccinated individuals (n = 782) in April 2021. While no effect could be found for freedoms, the share of participants willing to be vaccinated increased with the payment amount. However, a significant change required large rewards of 3,250 EUR or more. While monetary incentives could increase vaccination uptake by a few percentage points, the high costs of implementation challenge the efficiency of the measure and call for alternatives. As the data suggest that considering vaccination as safe, necessary, and prosocial increases an individual’s likelihood of wanting to get vaccinated without payment, interventions should focus on these features when promoting vaccination against COVID-19.

Engagement in Digital Mental Health Interventions: Can Monetary Incentives Help?

Digital mental health interventions (DMHI) are scalable and cost-effective strategies for increasing access to mental health care; however, dropout rates associated with digital interventions are high, particularly for open-access digital interventions. While some studies have focused on predictors of dropout from digital mental health programs, few studies have focused on engagement features that might improve engagement. In this perspective article, we discuss whether monetary incentives (MI) are one avenue to increasing user engagement in DMHI. We begin by reviewing the literature on the effects of MI for behavior change in health domains (e.g., dietary behaviors, substance use, and medication adherence). Then, drawing on a pilot study we conducted to test the effects of different levels of MI on usage and improvement in subjective well-being among users of a DMHI (Happify), we discuss the potential applications of MI for DMHI, the potential drawbacks of financial incentives in this context, and open questions for future research.

Healthy Food Prescription Programs and their Impact on Dietary Behavior and Cardiometabolic Risk Factors: A Systematic Review and Meta-Analysis

The enormous burden of diet-related chronic diseases has prompted interest in healthy food prescription programs. Yet, the impact of such programs remains unclear. The aim of this study was to conduct a systematic review of healthy food prescription programs and evaluate their impact on dietary behavior and cardiometabolic parameters by meta-analysis. A systematic search was carried out in Medline, Embase, Scopus, and Cochrane Central Register of Controlled Trials databases since their inception to 3 January, 2020 without language restriction. A systematic search of interventional studies investigating the effect of healthy food prescription on diet quality and/or cardiometabolic risk factors including BMI, systolic (SBP) and diastolic blood pressure (DBP), glycated hemoglobin (HbA1c), or blood lipids was carried out. Thirteen studies were identified for inclusion, most of which were quasi-experimental (pre/post) interventions without a control group (n = 9). Pooled estimates revealed a 22% (95% CI: 12, 32; n = 5 studies, n = 1039 participants; I2 = 97%) increase in fruit and vegetable consumption, corresponding to 0.8 higher daily servings (95% CI: 0.2, 1.4; I2 = 96%). BMI decreased by 0.6 kg/m2 (95% CI: 0.2, 1.1; I2 = 6.4%) and HbA1c by 0.8% (95% CI: 0.1, 1.6; I2 = 92%). No significant change was observed in other cardiometabolic parameters. These findings should be interpreted with caution in light of considerable heterogeneity, methodological limitations of the included studies, and moderate to very low certainty of evidence. Our results support the need for well-designed, large, randomized controlled trials in various settings to further establish the efficacy of healthy food prescription programs on diet quality and cardiometabolic health.

Money is not everything: experimental evidence that payments do not increase willingness to be vaccinated against COVID-19

Rapid, large-scale uptake of new vaccines against COVID-19 will be crucial to decrease infections and end the pandemic. In a recent article in this journal, Julian Savulescu argued in favour of monetary incentives to convince more people to be vaccinated once the vaccine becomes available. To evaluate the potential of his suggestion, we conducted an experiment investigating the impact of payments and the communication of individual and prosocial benefits of high vaccination rates on vaccination intentions. Our results revealed that none of these interventions or their combinations increased willingness to be vaccinated shortly after a vaccine becomes available. Consequently, decision makers should be cautious about introducing monetary incentives and instead focus on interventions that increase confidence in vaccine safety first, as this has shown to be an especially important factor regarding the demand for the new COVID-19 vaccines.

Theory of Planned Behavior Analysis of Social Distancing During the COVID-19 Pandemic: Focusing on the Intention-Behavior Gap

BACKGROUND

As COVID-19 continues to spread globally, it is important to understand psychological factors that may influence compliance with social distancing.

PURPOSE

The present study examined whether Theory of Planned Behavior (TPB) constructs were associated with social distancing, with a focus on exploring moderators of the intention-behavior relationship.

METHODS

Using a longitudinal design, U.S. adults (N = 507) self-reported TPB constructs and social distancing behavior at baseline and 3 months later. Participants were from 48 U.S. States and the District of Columbia and were on average 50.39 years old (SD = 15.32, range = 18-80). The majority were Non-Hispanic White (71.6%), had a bachelor's degree or higher (55.3%), and resided in suburban areas (55.8%).

RESULTS

While positive attitudes toward social distancing increased over time (p = .002), subjective norms weakened (p < .001) and perceived behavioral control (PBC) remained stable (p = .22). Interestingly, despite an increase in intentions from baseline to follow-up (p < .001), there was a significant decrease in social distancing behavior over time (p < .001). Consistent with the TPB, baseline attitudes (p < .001), subjective norms (p < .001), and PBC (p < .001) for social distancing were all associated with baseline intentions to social distance. In turn, baseline intentions were significantly associated with social distancing behavior at follow-up (p < .001). Younger adults (p < .001) and non-White participants (p = .002) displayed a greater intention-behavior gap relative to older and White participants. In contrast, participants with more stable intentions over time displayed a stronger intention-behavior relationship (p < .001).

CONCLUSIONS

Targeting individuals' attitudes, norms, and PBC may effectively promote protective behaviors intended to mitigate the spread of COVID-19 and similar viral outbreaks. Future research should examine effective strategies for translating social distancing intentions into actions.

Women's exercise identity increases after a 16-week exercise RCT and is linked to behavior maintenance at follow-up

BACKGROUND

Regular exercise is critical for disease prevention, but adherence to public health guidelines is poor. Exercise identity is purported to be associated with exercise behavior maintenance, but the extant literature is largely cross-sectional and of low/modest quality.

PURPOSE

To examine change in exercise identity after completion of a supervised exercise intervention, as well as associations between change in exercise identity and exercise maintenance at 6-months follow-up.

METHODS

N = 276 insufficiently physically active women were randomized to a 16-week, supervised exercise training intervention with 4 conditions fully crossed on intensity (vigorous/moderate) and duration (long/short). Exercise identity was measured pre- and post-intervention and assessments of exercise motivation and behavior frequency were collected at 6-months post-intervention follow-up.

RESULTS

On average, participants experienced a statistically significant change in exercise identity over the course of the intervention, t(128) = 7.94, p < .001, but identity change scores did not differ across training conditions, p = .91. Identity change was significantly positively related to changes in other theory-informed, motivation-based determinants of exercise, and predicted an additional 16.17 minutes of exercise per week, on average, at follow-up, b = 16.76, t(103) = 2.30, p = .023.

CONCLUSIONS

Participants experienced increased self-identification with exercise after 16-weeks of training, but training volume did not influence the amount of identity change. As expected, greater change in exercise identity was associated with higher levels of exercise behavior at 6-months post-intervention follow-up (ClinicalTrials.gov number NCT02032628).

Randomized controlled trials of self-monitoring interventions with or without incentives for diet and exercise among individuals with overweight or obesity: Psychological and behavioural effects

OBJECTIVES

To test the effects of three behavioural interventions (daily monetary incentives + self-monitoring, delayed lump sum monetary incentives + self-monitoring, and self-monitoring only) on psychological constructs and fruit and vegetable consumption or physical activity behaviour change among a sample of adults with overweight or obesity.

DESIGN

A pair of 3-arm longitudinal randomized controlled trials compared daily monetary incentives + self-monitoring, delayed lump sum monetary incentives + self-monitoring, and self-monitoring only interventions for either fruit and vegetable consumption or physical activity.

METHODS

Individuals reporting elevated weight status and insufficient engagement in one of the target behaviours were randomly assigned to one of three 3-week interventions. All three interventions involved daily self-monitoring of the behaviour, and two provided monetary incentives contingent upon reported behaviour. Participants completed measures of psychological constructs and reported behaviour at baseline, the end of the intervention, and two and four weeks post-intervention.

RESULTS

Participants across all three intervention conditions demonstrated increased engagement in the target behaviour from pre- to post-intervention and reported behaviour remained above baseline levels at both follow-up time points. Increases in reported behaviour during the intervention were associated with increases in self-efficacy, and this enhanced self-efficacy prospectively predicted sustained reported behaviour at follow-up. However, contrary to hypotheses, the incentive interventions including self-monitoring were not more efficacious than self-monitoring alone, and increased reported behaviour was not associated with enhancements in attitudes.

CONCLUSIONS

Self-monitoring interventions can aid behaviour change efforts, and behavioural practice during these interventions can increase self-efficacy. However, among adults with overweight or obesity who are seeking behaviour change interventions, incentive-based self-monitoring approaches may not be superior to self-monitoring alone in driving behaviour change and maintenance.

Interindividual differences in incentive sensitivity moderate motivational effects of competition and cooperation on motor performance

Established research has documented the pervasive influence of incentives (i.e., food, sex, money) on animal and human behavior. Additionally, motivational theories postulating intra–individually stable preferences for specific types of incentives (i.e., motives) highlight that effects of a given incentive are highly dependent on the motive disposition of the individual. Indeed, also research on motor performance has documented the interactive effects of motives and motive–specific incentives on motor outcomes. However, the majority of this research has relied on correlational designs focusing on the effects of the achievement motive, with few studies addressing the role of the affiliation and power motive. In order to extend findings in this domain, we tested whether a fit between individuals’ power (affiliation) motive and incentives of competition (cooperation) would improve motor performance. Following baseline measures, participants performed a dart–throwing task as part of a dyadic performance (i.e., cooperative) or a one–on–one competition scenario. In the dyadic performance scenario, a stronger affiliation motive did not translate to better performance. However, in the one–on–one competition scenario a stronger power motive was associated with better performance. Results highlight the role of the power motive in predicting motor performance, particularly in competitive situations.

A crossed-disciplinary evaluation of parental perceptions surrounding pediatric non-invasive brain stimulation research

Purpose –

Recruitment for pediatric non-invasive brain stimulation (NIBS) studies is often challenged by low enrollment. Understanding parental perceptions regarding NIBS is crucial to develop new communication strategies to increase enrollment.

Design/methodology/approach –

Integrating a crossed-disciplinary approach, the authors conducted a survey at the 2018 Minnesota State Fair querying the perception of risk and preferences of current and future parents associated with pediatric NIBS research. The survey consisted of 28 closed-text questions including demographics, photographs portraying NIBS, terminologies and factors related to NIBS studies.

Findings –

Complete surveys were analyzed from 622 parent participants. A significant number of participants (42.8%) perceived the photographs of NIBS as "risky." Additionally, 65.43% perceived the term "Non-invasive brain therapy" as not risky, a word combination not currently being used when recruiting potential participants. Over 90% (561/622) of participants chose the photograph of child-friendly MRI suite.

Research limitations/implications –

Although this survey identified aspects crucial in recruitment for pediatric NIBS research, there were limitations. For example, the authors did not record the sex or demographic distribution (e.g. rural versus urban setting) of the participants. These factors may also influence recruitment messaging.

Originality/value –

For important medical research to impact and improve the lives of the potential remedies, participation by the public in clinical trials is necessary. Often the general public perceives the trials as risky as a result of poor marketing communication recruitment material. This study sought to be understood if how the message is encoded has an impact on the decoding by the receiver.

Interventions for increasing fruit and vegetable consumption in children aged five years and under

BACKGROUND

Insufficient consumption of fruits and vegetables in childhood increases the risk of future non-communicable diseases, including cardiovascular disease. Testing the effects of interventions to increase consumption of fruit and vegetables, including those focused on specific child-feeding strategies or broader multicomponent interventions targeting the home or childcare environment is required to assess the potential to reduce this disease burden.

OBJECTIVES

To assess the effectiveness, cost effectiveness and associated adverse events of interventions designed to increase the consumption of fruit, vegetables or both amongst children aged five years and under.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase and two clinical trials registries to identify eligible trials on 25 January 2020. We searched Proquest Dissertations and Theses in November 2019. We reviewed reference lists of included trials and handsearched three international nutrition journals. We contacted authors of included trials to identify further potentially relevant trials.

SELECTION CRITERIA

We included randomised controlled trials, including cluster-randomised controlled trials and cross-over trials, of any intervention primarily targeting consumption of fruit, vegetables or both among children aged five years and under, and incorporating a dietary or biochemical assessment of fruit or vegetable consumption. Two review authors independently screened titles and abstracts of identified papers; a third review author resolved disagreements.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the risks of bias of included trials; a third review author resolved disagreements. Due to unexplained heterogeneity, we used random-effects models in meta-analyses for the primary review outcomes where we identified sufficient trials. We calculated standardised mean differences (SMDs) to account for the heterogeneity of fruit and vegetable consumption measures. We conducted assessments of risks of bias and evaluated the quality of evidence (GRADE approach) using Cochrane procedures.

MAIN RESULTS

We included 80 trials with 218 trial arms and 12,965 participants. Fifty trials examined the impact of child-feeding practices (e.g. repeated food exposure) in increasing child vegetable intake. Fifteen trials examined the impact of parent nutrition education only in increasing child fruit and vegetable intake. Fourteen trials examined the impact of multicomponent interventions (e.g. parent nutrition education and preschool policy changes) in increasing child fruit and vegetable intake. Two trials examined the effect of a nutrition education intervention delivered to children in increasing child fruit and vegetable intake. One trial examined the impact of a child-focused mindfulness intervention in increasing vegetable intake. We judged 23 of the 80 included trials as free from high risks of bias across all domains. Performance, detection and attrition bias were the most common domains judged at high risk of bias for the remaining trials. There is low-quality evidence that child-feeding practices versus no intervention may have a small positive effect on child vegetable consumption, equivalent to an increase of 5.30 grams as-desired consumption of vegetables (SMD 0.50, 95% CI 0.29 to 0.71; 19 trials, 2140 participants; mean post-intervention follow-up = 8.3 weeks). Multicomponent interventions versus no intervention has a small effect on child consumption of fruit and vegetables (SMD 0.32, 95% CI 0.09 to 0.55; 9 trials, 2961 participants; moderate-quality evidence; mean post-intervention follow-up = 5.4 weeks), equivalent to an increase of 0.34 cups of fruit and vegetables a day. It is uncertain whether there are any short-term differences in child consumption of fruit and vegetables in meta-analyses of trials examining parent nutrition education versus no intervention (SMD 0.13, 95% CI -0.02 to 0.28; 11 trials, 3050 participants; very low-quality evidence; mean post-intervention follow-up = 13.2 weeks). We were unable to pool child nutrition education interventions in meta-analysis; both trials reported a positive intervention effect on child consumption of fruit and vegetables (low-quality evidence). Very few trials reported long-term effectiveness (6 trials), cost effectiveness (1 trial) or unintended adverse consequences of interventions (2 trials), limiting our ability to assess these outcomes. Trials reported receiving governmental or charitable funds, except for four trials reporting industry funding.

AUTHORS' CONCLUSIONS

Despite identifying 80 eligible trials of various intervention approaches, the evidence for how to increase children's fruit and vegetable consumption remains limited in terms of quality of evidence and magnitude of effect. Of the types of interventions identified, there was moderate-quality evidence that multicomponent interventions probably lead to, and low-quality evidence that child-feeding practice may lead to, only small increases in fruit and vegetable consumption in children aged five years and under. It is uncertain whether parent nutrition education or child nutrition education interventions alone are effective in increasing fruit and vegetable consumption in children aged five years and under. Our confidence in effect estimates for all intervention approaches, with the exception of multicomponent interventions, is limited on the basis of the very low to low-quality evidence. Long-term follow-up of at least 12 months is required and future research should adopt more rigorous methods to advance the field. This is a living systematic review. Living systematic reviews offer a new approach to review updating, in which the review is continually updated, incorporating relevant new evidence as it becomes available. Please refer to the Cochrane Database of Systematic Reviews for the current status of this review.

Using fundraising incentives and point-of-purchase nutrition promotion to improve food choices among school families in restaurants: a pilot and feasibility study

OBJECTIVE

To assess the feasibility and efficacy of in-restaurant interventions aiming to promote healthy choices via fundraising incentives benefiting school wellness programmes and point-of-purchase nutrition promotion.

DESIGN

Twelve schools were randomly assigned to one of the two intervention periods: Fundraising Incentive (FI) donated funds for visiting the study restaurant and Fundraising-Healthy Eating Incentive (F-HEI) included FI with additional funds given when selecting a healthier item. Both conditions included point-of-purchase nutrition promotions. Families were recruited to attend their designated intervention and complete a survey. Feasibility was assessed based on recruitment and participation, implementation fidelity and intervention acceptability. Efficacy was assessed by comparing participant receipts between intervention periods and by comparing overall restaurant sales during intervention v. two no-intervention time frames.

SETTING

Fast-casual restaurant in Southern California.

PARTICIPANTS

Parents with children attending participating schools.

RESULTS

Eighty-one families visited the restaurant during the intervention, with sixty-six completing surveys. All study activities were implemented successfully, but school family participation in the intervention was low (0·95 %). Among participants completing surveys, all indicated satisfaction with the programme. The percentage of healthier items ordered was significantly greater during both FI (χ2 = 5·97, P = 0·01) and F-HEI (χ2 = 8·84, P = 0·003) v. Comparison 2. Results were similar but did not reach statistical significance when comparing the interventions to Comparison 1.

CONCLUSIONS

Results support potential efficacy of this programme, but more research is needed to inform feasibility. Fidelity and acceptability data supported feasibility, but participation rates were low in this initial study. Methods evaluating this intervention with a greater proportion of parents should be considered.

Interventions for increasing fruit and vegetable consumption in children aged five years and under

BACKGROUND

Insufficient consumption of fruits and vegetables in childhood increases the risk of future non-communicable diseases, including cardiovascular disease. Interventions to increase consumption of fruit and vegetables, such as those focused on specific child-feeding strategies and parent nutrition education interventions in early childhood may therefore be an effective strategy in reducing this disease burden.

OBJECTIVES

To assess the effectiveness, cost effectiveness and associated adverse events of interventions designed to increase the consumption of fruit, vegetables or both amongst children aged five years and under.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase and two clinical trials registries to identify eligible trials on 25 August 2019. We searched Proquest Dissertations and Theses in May 2019. We reviewed reference lists of included trials and handsearched three international nutrition journals. We contacted authors of included trials to identify further potentially relevant trials.

SELECTION CRITERIA

We included randomised controlled trials, including cluster-randomised controlled trials and cross-over trials, of any intervention primarily targeting consumption of fruit, vegetables or both among children aged five years and under, and incorporating a dietary or biochemical assessment of fruit or vegetable consumption. Two review authors independently screened titles and abstracts of identified papers; a third review author resolved disagreements.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the risks of bias of included trials; a third review author resolved disagreements. Due to unexplained heterogeneity, we used random-effects models in meta-analyses for the primary review outcomes where we identified sufficient trials. We calculated standardised mean differences (SMDs) to account for the heterogeneity of fruit and vegetable consumption measures. We conducted assessments of risks of bias and evaluated the quality of evidence (GRADE approach) using Cochrane procedures.

MAIN RESULTS

We included 78 trials with 214 trial arms and 13,746 participants. Forty-eight trials examined the impact of child-feeding practices (e.g. repeated food exposure) in increasing child vegetable intake. Fifteen trials examined the impact of parent nutrition education in increasing child fruit and vegetable intake. Fourteen trials examined the impact of multicomponent interventions (e.g. parent nutrition education and preschool policy changes) in increasing child fruit and vegetable intake. Two trials examined the effect of a nutrition education intervention delivered to children in increasing child fruit and vegetable intake. One trial examined the impact of a child-focused mindfulness intervention in increasing vegetable intake. We judged 20 of the 78 included trials as free from high risks of bias across all domains. Performance, detection and attrition bias were the most common domains judged at high risk of bias for the remaining trials. There is very low-quality evidence that child-feeding practices versus no intervention may have a small positive effect on child vegetable consumption equivalent to an increase of 4.45 g as-desired consumption of vegetables (SMD 0.42, 95% CI 0.23 to 0.60; 18 trials, 2004 participants; mean post-intervention follow-up = 8.2 weeks). Multicomponent interventions versus no intervention has a small effect on child consumption of fruit and vegetables (SMD 0.34, 95% CI 0.10 to 0.57; 9 trials, 3022 participants; moderate-quality evidence; mean post-intervention follow-up = 5.4 weeks), equivalent to an increase of 0.36 cups of fruit and vegetables per day. It is uncertain whether there are any short-term differences in child consumption of fruit and vegetables in meta-analyses of trials examining parent nutrition education versus no intervention (SMD 0.12, 95% CI -0.03 to 0.28; 11 trials, 3078 participants; very low-quality evidence; mean post-intervention follow-up = 13.2 weeks). We were unable to pool child nutrition education interventions in meta-analysis; both trials reported a positive intervention effect on child consumption of fruit and vegetables (low-quality evidence). Very few trials reported long-term effectiveness (6 trials), cost effectiveness (1 trial) and unintended adverse consequences of interventions (2 trials), limiting their assessment. Trials reported receiving governmental or charitable funds, except for four trials reporting industry funding.

AUTHORS' CONCLUSIONS

Despite identifying 78 eligible trials of various intervention approaches, the evidence for how to increase children's fruit and vegetable consumption remains limited. There was very low-quality evidence that child-feeding practice may lead to, and moderate-quality evidence that multicomponent interventions probably lead to small increases in fruit and vegetable consumption in children aged five years and younger. It is uncertain whether parent nutrition education interventions are effective in increasing fruit and vegetable consumption in children aged five years and younger. Given that the quality of the evidence is very low or low, future research will likely change estimates and conclusions. Long-term follow-up of at least 12 months is required and future research should adopt more rigorous methods to advance the field. This is a living systematic review. Living systematic reviews offer a new approach to review updating, in which the review is continually updated, incorporating relevant new evidence as it becomes available. Please refer to the Cochrane Database of Systematic Reviews for the current status of this review.

Stress and number of servings of fruit and vegetables consumed: Buffering effects of monetary incentives

Diet is a key factor of human health, and additional research is needed in order to understand the psychological causes, consequences, and moderators of dietary behavior. Participants in two studies in the United States completed a 21-day intervention that involved either self-monitoring their fruit and vegetable consumption or self-monitoring combined with earning monetary incentives for behavior. Each day, participants reported their stress, affect, and consumption of fruits and vegetables. Hierarchical linear mixed effects model results suggest that on average, daily reports of higher stress were associated with fewer fruits and vegetables consumed on that day. This effect was moderated by incentive condition, such that the relationship between stress and fruit and vegetable consumption was reduced among incented participants. There was also a marginal negative effect of time on consumption of fruits and vegetables, but this was also significantly moderated by condition, such that those participants who did not receive incentives decreased their daily servings, while incented participants did not decrease over the course of the intervention. These studies suggest that incentives may be a novel method for buffering against the negative effect of daily stress on eating a healthy diet.

Knowledge, Attitudes, Beliefs and Behaviors regarding Fruits and Vegetables among Cost-offset Community-Supported Agriculture (CSA) Applicants, Purchasers, and a Comparison Sample

Community-supported agriculture (CSA) participation has been associated with high fruit and vegetable (FV) consumption, which may be due to better access to FV for CSA purchasers, or to positive knowledge, attitudes, and beliefs (KAB) regarding healthy eating among CSA applicants. The objective of this study was to examine KAB and consumption, in association with application to a cost-offset CSA (CO-CSA) program, and with CO-CSA purchase among applicants. We conducted a cross-sectional survey of CO-CSA applicants and a comparison sample in August 2017. All respondents were English-reading adults with a child 2–12 years old and household income of ≤185% of the federal poverty level. Among CO-CSA applicants, some were CO-CSA purchasers (n = 46) and some were not (n = 18). An online comparison sample met equivalent eligibility criteria, but had not participated in CSA for three years (n = 105). We compared CO-CSA applicants to the comparison sample, and compared purchasers and non-purchaser sub-groups, using Mann-Whitney U tests and chi-square analysis. CO-CSA applicants reported better knowledge, self-efficacy, home habits, and diet than the comparison sample. Among applicants, CO-CSA purchasers and non-purchasers had equivalent KAB, but children in purchaser households had higher FV consumption than in non-purchaser households (4.14 vs. 1.83 cups, p = 0.001). Future research should explore associations between CO-CSA participation and diet using experimental methods.

The short- and long-term impact of an incentive intervention on healthier eating: a quasi-experiment in primary- and secondary-school cafeterias in Brazil

OBJECTIVE

To assess the short- and long-term effectiveness of a lottery incentive intervention to promote the purchase of healthy products in school cafeterias.

DESIGN

A quasi-experiment in which students' purchases in intervention schools were analysed in a pre-post analysis and also compared with a control school in a difference-in-differences model. A hierarchical linear model assessed the mean number of promoted healthy products purchased daily per participant before (twenty-six weekdays), during (nine weekdays) and after (twenty-eight weekdays) the intervention period. Sex, age and prior purchasing behaviour served as covariates.

SETTING

Convenience sample of school cafeterias using a debit-card payment method that allowed for the assessment of students' purchasing behaviour.ParticipantsStudents who used the pre-paid card to buy snacks at the school cafeteria. A total of 352 students (208 in intervention schools and 144 in control school) were included in the final analyses.

RESULTS

The incentives programme significantly increased the purchase of promoted healthy products during (v. before) the intervention period in intervention schools (P&lt;0·001), especially among younger children (P=0·036). Among the students who purchased the promoted healthier products during the intervention, there was an increase in total number of purchased products (healthy non-promoted, but also of less healthy products). Sex and past consumption behaviour did not influence the response to incentives in the short term. On average, no long-term effect was observed.

CONCLUSIONS

Long-term and negative spillover effects must be taken into consideration for a complete understanding of the effects of incentives on healthier eating.

Maternal Behavioral Health: Fertile Ground for Behavior Analysis

The World Health Organization has identified four behavioral health priorities as risk factors for noncommunicable diseases in maternal populations: tobacco use, harmful alcohol use, poor nutrition, and lack of physical activity. These risk factors also significantly affect pregnant and immediately postpartum mothers, doubling the health risk and economic burden by adversely affecting maternal and birth or infant outcomes. Psychosocial and behavioral interventions are ideal for pregnant and immediately postpartum women as opposed to pharmacotherapy. Among other behavioral interventions, the use of incentives based on the principles of reinforcement has been a successful yet controversial way to change health behaviors. Implementing an incentive-based intervention in maternal health often brings up social validity concerns. The existing guideline on how to develop and conduct research in incentive-based interventions for maternal health lacks enough information on the specific variables to control for to maintain the intervention's effectiveness. This article outlines some of the critical variables in implementing an effective behavior-analytic intervention and addressing social validity concerns to change maternal behaviors in a sustainable manner, along with specific research topics needed in the field to prevent adverse maternal, birth, and infant outcomes.

Interventions for increasing fruit and vegetable consumption in children aged five years and under

BACKGROUND

Insufficient consumption of fruits and vegetables in childhood increases the risk of future non-communicable diseases, including cardiovascular disease. Interventions to increase consumption of fruit and vegetables, such as those focused on specific child-feeding strategies and parent nutrition education interventions in early childhood may therefore be an effective strategy in reducing this disease burden.

OBJECTIVES

To assess the effectiveness, cost effectiveness and associated adverse events of interventions designed to increase the consumption of fruit, vegetables or both amongst children aged five years and under.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase and two clinical trials registries to identify eligible trials on 25 January 2018. We searched Proquest Dissertations and Theses in November 2017. We reviewed reference lists of included trials and handsearched three international nutrition journals. We contacted authors of included studies to identify further potentially relevant trials.

SELECTION CRITERIA

We included randomised controlled trials, including cluster-randomised controlled trials and cross-over trials, of any intervention primarily targeting consumption of fruit, vegetables or both among children aged five years and under, and incorporating a dietary or biochemical assessment of fruit or vegetable consumption. Two review authors independently screened titles and abstracts of identified papers; a third review author resolved disagreements.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the risks of bias of included studies; a third review author resolved disagreements. Due to unexplained heterogeneity, we used random-effects models in meta-analyses for the primary review outcomes where we identified sufficient trials. We calculated standardised mean differences (SMDs) to account for the heterogeneity of fruit and vegetable consumption measures. We conducted assessments of risks of bias and evaluated the quality of evidence (GRADE approach) using Cochrane procedures.

MAIN RESULTS

We included 63 trials with 178 trial arms and 11,698 participants. Thirty-nine trials examined the impact of child-feeding practices (e.g. repeated food exposure) in increasing child vegetable intake. Fourteen trials examined the impact of parent nutrition education in increasing child fruit and vegetable intake. Nine studies examined the impact of multicomponent interventions (e.g. parent nutrition education and preschool policy changes) in increasing child fruit and vegetable intake. One study examined the effect of a nutrition education intervention delivered to children in increasing child fruit and vegetable intake.We judged 14 of the 63 included trials as free from high risks of bias across all domains; performance, detection and attrition bias were the most common domains judged at high risk of bias for the remaining studies.There is very low quality evidence that child-feeding practices versus no intervention may have a small positive effect on child vegetable consumption equivalent to an increase of 3.50 g as-desired consumption of vegetables (SMD 0.33, 95% CI 0.13 to 0.54; participants = 1741; studies = 13). Multicomponent interventions versus no intervention may have a very small effect on child consumption of fruit and vegetables (SMD 0.35, 95% CI 0.04 to 0.66; participants = 2009; studies = 5; low-quality evidence), equivalent to an increase of 0.37 cups of fruit and vegetables per day. It is uncertain whether there are any short-term differences in child consumption of fruit and vegetables in meta-analyses of trials examining parent nutrition education versus no intervention (SMD 0.12, 95% CI -0.03 to 0.28; participants = 3078; studies = 11; very low-quality evidence).Insufficient data were available to assess long-term effectiveness, cost effectiveness and unintended adverse consequences of interventions. Studies reported receiving governmental or charitable funds, except for four studies reporting industry funding.

AUTHORS' CONCLUSIONS

Despite identifying 63 eligible trials of various intervention approaches, the evidence for how to increase children's fruit and vegetable consumption remains limited. There was very low- and low-quality evidence respectively that child-feeding practice and multicomponent interventions may lead to very small increases in fruit and vegetable consumption in children aged five years and younger. It is uncertain whether parent nutrition education interventions are effective in increasing fruit and vegetable consumption in children aged five years and younger. Given that the quality of the evidence is very low or low, future research will likely change estimates and conclusions. Long-term follow-up is required and future research should adopt more rigorous methods to advance the field.This is a living systematic review. Living systematic reviews offer a new approach to review updating, in which the review is continually updated, incorporating relevant new evidence as it becomes available. Please refer to the Cochrane Database of Systematic Reviews for the current status of this review.