Does a future-oriented temporal perspective relate to body mass index, eating, and exercise? A meta-analysis

How future orientations predict healthy outcomes: Information avoidance as a potential mechanism

This study elucidates whether information avoidance may help explain demonstrated links between future orientation and health. In an online study, college students reported their self-reported prevention and detection health behaviors and responded to a prevention and detection health message. Path analyses indicated that information avoidance mediated the relationship with the future orientations (optimism and consideration of future consequences), such that, greater and more positive future orientations were associated with less information avoidance, and less information avoidance was associated with greater self-reported health behaviors and positive responses to health information. Correlational analyses revealed that information avoidance was particularly related to health outcomes, and to a greater extent than future orientations. Our findings join a growing literature showing the importance of information avoidance for a variety of health behaviors and suggest a potential intervention target for individuals whose characteristic ways of (not) thinking about their future might keep them unaware and unhealthy.

Investigating psychological mechanisms of self-controlled decisions for food and leisure activity

Maintaining a healthy body weight requires balancing energy intake and expenditure. While previous research investigated energy input or food decisions, little is known about energy output or leisure activity decisions. By combining experimental decision-making paradigms and computational approaches, we investigated the psychological mechanisms of self-controlled food and leisure activity decisions through the effects of reward-oriented and health-oriented preferences as well as body weight status, stress, and coping. Based on individual's responses, the self-controlled food and leisure activity choices were indexed as the proportions of "no" unhealthy but tasty (or enjoyable) (inhibitory self-control against short-term pleasure) and "yes" healthy but not tasty (or not enjoyable) responses (initiatory self-control for long-term health benefits). The successful self-control decisions for food and leisure activity were positively correlated with each other, r = 22, p < .01. In beta regression analyses, the successful self-controlled food decisions decreased as the taste-oriented process increased, β = - 0.50, z = -2.99, p < .005, and increased as the health-oriented process increased, β = 1.57, z = 4.68, p < .001. Similarly, the successful self-controlled leisure activity decisions decreased as the enjoyment-oriented process increased, β = - 0.79, z = -5.31, p < .001, and increased as the health-oriented process increased, β = 0.66, z = 2.19, p < .05. The effects of the other factors were not significant. Overall, our findings demonstrated the mutual interrelationship between food and leisure activity decision-making and suggest that encouraging health-oriented processes may benefit both energy input and expenditure domains and improve self-controlled choices.

Balancing Time for Health Behaviors: Associations of Time Perspective With Physical Activity and Weight Management in Older Adults

PURPOSE

To examine associations between time perspective and health promotion behaviors of physical activity and weight management.

DESIGN

Quantitative cross-sectional.

SETTING

This study is part of the Betula project on aging, memory, and dementia in Northern Sweden.

SUBJECTS

417 older adults aged between 55 and 85 years.

MEASURES

Swedish-Zimbardo Time Perspective Inventory; Physical Activity in the past year, past week, and in comparison with others of similar age; Weight Management = Body Mass Index (BMI; kg/m2).

RESULTS

After controlling for age, sex, and years of education, hierarchical linear regression indicated a Balanced Time Perspective was significantly associated with more physical activity in the past year (P = .04), the past week (P < .001), and in comparison with others (P < .01). Past Negative time perspective was associated with less physical activity in the past year (P = .03), and in comparison with others (P = .03). Present Fatalistic was associated with less physical activity during the past week (P = .03), and in comparison with others (P = .01). Present Hedonistic was associated with more physical activity the past week (P = .03), and in comparison with others (P = .03). Past Negative was associated with higher BMI (P = .02), and Future Negative were associated with lower BMI (P = .01). Taken collectively, greater positivity and flexibility across time perspectives was associated with more physical activity, whereas negative oriented time perspectives related with less physical activity and poorer weight management.

CONCLUSION

Time perspective can be associated with health behaviors in older adults and have implications for health across the lifespan. Health promotion interventions may target older adults' enjoyment of exercise and weight management in the present, rather than highlight potential negative health outcomes in the future.

Persuasive Effects of Temporal Framing in Health Messaging: A Meta-Analysis

This meta-analysis investigated the persuasive effects of temporal framing in health messaging. Our analysis included 39 message pairs from 22 studies in 20 articles (N = 4,998) that examined the effects of temporal framing (i.e. present-oriented messages vs. future-oriented messages) on attitudes, intentions, and behaviors in health contexts. We found that present-oriented messages were significantly more persuasive than future-oriented messages in terms of intentions and integrated persuasive outcomes. Effects of temporal framing on attitudes and behaviors were not statistically significant. We tested six moderators of temporal framing effects (gain vs. loss framing, temporal framing operationalization, behavior type, timing of effect assessment, age, CFC levels) but none of them was statistically significant. Implications for future temporal framing research are discussed.

Impact of Unmet Social Needs, Scarcity, and Future Discounting on Adherence to Treatment in Children With Asthma: Protocol for a Prospective Cohort Study

BACKGROUND

Asthma is one of the most prevalent chronic diseases of childhood and disproportionately affects children with lower socioeconomic status. Controller medications such as inhaled corticosteroids significantly reduce asthma exacerbations and improve symptoms. However, a large proportion of children still have poor asthma control, in part owing to suboptimal adherence. Financial barriers contribute to hindering adherence, as do behavioral factors related to low income. For example, unmet social needs for food, lodging, and childcare may create stress and worry in parents, negatively influencing medication adherence. These needs are also cognitively taxing and force families to focus on immediate needs, leading to scarcity and heightening future discounting; thus, there is the tendency to attribute greater value to the present than to the future in making decisions.

OBJECTIVE

In this project, we will investigate the relationship between unmet social needs, scarcity, and future discounting as well as their predictive power over time on medication adherence in children with asthma.

METHODS

This 12-month prospective observational cohort study will recruit 200 families of children aged 2 to 17 years at the Asthma Clinic of the Centre Hospitalier Universitaire Sainte-Justine, a tertiary care pediatric hospital in Montreal, Canada. The primary outcome will be adherence to controller medication, measured using the proportion of prescribed days covered during follow-up. Exploratory outcomes will include health care use. The main independent variables will be unmet social needs, scarcity, and future discounting, measured using validated instruments. These variables will be measured at recruitment as well as at 6- and 12-month follow-ups. Covariates will include sociodemographics, disease and treatment characteristics, and parental stress. Primary analysis will compare adherence to controller medication, measured using the proportion of prescribed days covered, between families with versus those without unmet social needs during the study period using multivariate linear regression.

RESULTS

The research activities of this study began in December 2021. Participant enrollment and data collection began in August 2022 and are expected to continue until September 2024.

CONCLUSIONS

This project will allow the documentation of the impact of unmet social needs, scarcity, and future discounting on adherence in children with asthma using robust metrics of adherence and validated measures of scarcity and future discounting. If the relationship between unmet social needs, behavioral factors, and adherence is supported by our findings, this will suggest the potential for novel targets for integrated social care interventions to improve adherence to controller medication and reduce risk across the life course for vulnerable children with asthma.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05278000; https://clinicaltrials.gov/ct2/show/NCT05278000.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/37318.

Effects of individual and dyadic decision-making and normative reference on delay discounting decisions

The tendency to devaluate delayed rewards, a phenomenon referred to as ‘discounting behaviour’, has been studied by wide-ranging research examining individuals choosing between sooner but smaller or later but larger rewards. Despite the fact that many real-life choices are embedded in a social context, the question of whether or not social collaboration can have an impact on such choices has not been addressed empirically. With this research, we aimed to fill this gap experimentally by implementing a novel choice selection procedure in order to study the interactive dynamics between two participants. This selection procedure allowed us to dissect the sequence of decision-making into its elements, starting from the very first individual preference to the solution of possible conflicting preferences in the dyad. In Experiment 1, we studied group decision-making on classical intertemporal choices to reveal the possible benefit of social collaboration on discounting and identified that the knowledge of the social situation in collective decision-making causes a reduction in discounting. In a pre-registered Experiment 2, we compared classical intertemporal choices with choices in a gamified version of a discounting paradigm in which the participants had a real-time experience trial by trial and for which a normative reference was present. We found that collective decision-making had a substantial impact on intertemporal decision-making, but was shaped by different types of choices. Classical intertemporal choices were rather susceptible to the contextual factors of decision-making, whereas in the gamified version that included a normative reference the decisions were reliably influenced by social collaboration and resulted in a lower discounting. The results in this paradigm replicate our original findings from former research.

Future Time Perspective and Bedtime Procrastination: The Mediating Role of Dual-Mode Self-Control and Problematic Smartphone Use

This study examined bedtime procrastination predictors and the development process concerning health behavior. Based on temporal self-regulation theory and the self-regulatory framework of time perspective, we examined the effects of future time perspective, dual-model of self-control, and problematic smartphone use on bedtime procrastination. Further, including the mediating role of dual-mode self-control and problematic smartphone use in the effects of future time perspective on bedtime procrastination among 3687 participants (38.73% male; M_age = 16.17 years, SD = 2.42, range = 11-23) Chinese students. The results showed that the future time perspective, dual-mode self-control, and problematic smartphone use had significant predictive effects on bedtime procrastination. Importantly, the negative effect of future time perspective on bedtime procrastination is mediated by the impulse system, control system, and problematic smartphone use separately and serially mediated by the impulse system and problematic smartphone use, rather than the control system and problematic smartphone use; these findings extend previous research on the contributing factors of bedtime procrastination and provide an empirical basis for promoting people to form healthy sleep habits.

Deprivation Has Inconsistent Effects on Delay Discounting: A Review

Delay discounting, the tendency for outcomes to be devalued as they are more temporally remote, has implications as a target for behavioral interventions. Because of these implications, it is important to understand how different states individuals may face, such as deprivation, influence the degree of delay discounting. Both dual systems models and state-trait views of delay discounting assume that deprivation may result in steeper delay discounting. Despite early inconsistencies and mixed results, researchers have sometimes asserted that deprivation increases delay discounting, with few qualifications. The aim of this review was to determine what empirical effect, if any, deprivation has on delay discounting. We considered many kinds of deprivation, such as deprivation from sleep, drugs, and food in humans and non-human animals. For 23 studies, we analyzed the effect of deprivation on delay discounting by computing effect sizes for the difference between delay discounting in a control, or baseline, condition and delay discounting in a deprived state. We discuss these 23 studies and other relevant studies found in our search in a narrative review. Overall, we found mixed effects of deprivation on delay discounting. The effect may depend on what type of deprivation participants faced. Effect sizes for deprivation types ranged from small for sleep deprivation (Hedge's gs between −0.21 and 0.07) to large for opiate deprivation (Hedge's gs between 0.42 and 1.72). We discuss possible reasons why the effect of deprivation on delay discounting may depend on deprivation type, including the use of imagined manipulations and deprivation intensity. The inconsistency in results across studies, even when comparing within the same type of deprivation, indicates that more experiments are needed to reach a consensus on the effects of deprivation on delay discounting. A basic understanding of how states affect delay discounting may inform translational efforts.

Executive function capacity links future thinking and exercise intent

OBJECTIVE

Environmental barriers limit exercise in adolescents, but the contribution of cognitive barriers are not as well characterized. Previous findings suggest future thinking may predict exercise intent, which has been linked to health and actual exercise. However, these models may be incomplete as they do not systematically incorporate potential cognitive contributions (e.g., executive function capacity) to exercise intent. This study investigated the possible mediating role of executive function capacity in the relation between future thinking and exercise intent.

METHODS

Data for the mediation models was collected from 101 adolescents aged 11-17 (M = 13.09) in a summer enrichment program. Adolescent participants completed self-report measures including Consideration of Future Consequences Scale (CFCS), Intent to Exercise, and Behavior Rating Inventory of Executive Function, Second Edition (BRIEF-2).

RESULTS

This study found that self-reported executive function capacity mediated the relation between future thinking and exercise intent even when controlling for age and subjective socioeconomic status.

CONCLUSIONS

While some exercise interventions aim to increase future thinking, this study provides support for additional research into how interventions may benefit from targeting executive function capacity directly to increase exercise intent and actual exercise.

Temporal discounting as a candidate behavioral marker of obesity

Although obesity is a result of processes operating at multiple levels, most forms result from decision-making behavior. The aim of this review was to examine the candidacy of temporal discounting (TD) (i.e. the reduction in the value of a reinforcer as a function of the delay to its receipt) as a behavioral marker of obesity. For this purpose, we assessed whether TD has the ability to: identify risk for obesity development, diagnose obesity, track obesity progression, predict treatment prognosis/outcomes, and measure treatment effectiveness. Three databases (Pubmed, PsycINFO, and Web of Science) were searched using a combination of terms related to TD and obesity. A total of 153 papers were reviewed. Several areas show strong evidence of TD's predictive utility as a behavioral marker of obesity (e.g., distinguishing obese from non obese). However, other areas have limited and/or mixed evidence (e.g., predicting weight change). Given the positive relationship for TD in the majority of domains examined, further consideration for TD as a behavioral marker of obesity is warranted.

Letters to our Future Selves? High-Powered Replication Attempts Question Effects on Future Orientation, Delinquent Decisions, and Risky Investments

Enhancing people's future orientation, in particular continuity with their future selves, has been proposed as promising to mitigate self-control–related problem behavior. In two pre-registered, direct replication studies, we tested a subtle manipulation, that is, writing a letter to one's future self, in order to reduce delinquent decisions (van Gelder et al., 2013, Study 1) and risky investments (Monroe et al., 2017, Study 1). With samples of n = 314 and n = 463, which is 2.5 times the original studies' sample sizes, the results suggested that the expected effects are either non-existent or smaller than originally reported, and/or dependent on factors not examined. Vividness of the future self was successfully manipulated in Study 2, but manipulation checks overall indicated that the letter task is not reliable to alter future orientation. We discuss ideas to integrate self-affirmation approaches and to test less subtle manipulations in samples with substantial, myopia-related self-control deficits.

The psychology of obesity: An umbrella review and evidence-based map of the psychological correlates of heavier body weight

Psychological factors may explain why some people develop obesity and others remain a normal weight during their life course. We use an umbrella review approach to build an evidence-based map of the psychological correlates of heavier body weight. Synthesising findings from 42 meta-analyses that have examined associations between psychological factors and heavier body weight, we assessed level of evidence for a range of cognitive, psychosocial and mental health individual difference factors. There is convincing evidence that impaired mental health is associated with heavier body weight and highly suggestive evidence that numerous cognitive factors are associated with heavier body weight. However, the relatively low methodological quality of meta-analyses resulted in lower evidential certainty for most psychosocial factors. Psychological correlates of heavier body weight tended to be small in statistical size and on average, people with obesity were likely to be more psychologically similar than different to people with normal weight. We consider implications for understanding the development of heavier body weight and identifying effective public health interventions to reduce obesity.

The Time Is Ripe: Thinking about the Future Reduces Unhealthy Eating in Those with a Higher BMI

Research suggests that being oriented more towards the future (than the present) is correlated with healthier eating. However, this research tends to be correlational, and thus it is unclear whether inducing people to think about their future could increase healthy eating. Therefore, we investigated whether inducing people to think about their lives in the future versus the present would influence their intake of healthy (muesli) and unhealthy (Maltesers) food. Across two experiments, the effect of thinking about the future versus the present interacted with participants’ body mass index (BMI) to influence their consumption of unhealthy food, but no reliable effects were found for the consumption of healthy food. Among individuals with a higher BMI, thinking about their lives in the future resulted in lower consumption of the unhealthy food compared to thinking about their lives in the present. However, this effect was reversed for those with a lower BMI. In Experiment 2, we found no evidence that this effect was due to reduced impulsivity (as measured by a delay discounting task and a stop-signal task). This suggests that thinking about the future can reduce unhealthy eating among heavier people.

Individual differences in functional food consumption: The role of time perspective and the Big Five personality traits

Prior research suggests inconsistent relationships between individuals' personality traits, time perspective, and specific behavior. In a large representative sample of Norwegian consumers (N = 810), we investigated the relationships between the Big Five personality traits, domain-specific consideration of future consequences (CFC), and consumption of functional foods. Structural equation modeling was employed to test the hypothesized associations. Both CFC-Future and CFC-Immediate were positively related to the consumption of functional foods, whereas personality traits exerted no direct influence on consumption. Several significant associations between personality traits and CFC-Future and CFC-Immediate were found, and three of the five personality traits-Conscientiousness, Agreeableness, and Neuroticism-exerted indirect effects on consumption frequency via CFC-Future. Results support an integrative and hierarchical understanding of how personality traits and time perspective interact in explaining variation in functional food consumption. The findings support the notion that (domain-specific) CFC is better conceptualized as two distinct-albeit related constructs-that are shaped, in part, by broader personality traits.

Improvement of Working Memory is a Mechanism for Reductions in Delay Discounting Among Mid-Age Individuals in an Urban Medically Underserved Area

BACKGROUND

Delay discounting, or the tendency to devalue rewards as a function of their delayed receipt, is associated with myriad negative health behaviors. Individuals from medically underserved areas are disproportionately at risk for chronic health problems. The higher rates of delay discounting and consequent adverse outcomes evidenced among low-resource and unstable environments suggest this may be an important pathway to explain health disparities among this population.

PURPOSE

The current study examined the effectiveness of a computerized working memory training program to decrease rates of delay discounting among residents of a traditionally underserved region.

METHODS

Participants (N = 123) were recruited from a community center serving low income and homeless individuals. Subjects completed measures of delay discounting and working memory and then took part in either an active or control working memory training.

RESULTS

Analyses indicated that participants in the active condition demonstrated significant improvement in working memory and that this improvement mediated the relation between treatment condition and reductions in delay discounting.

CONCLUSIONS

Results suggest that a computerized intervention targeting working memory may be effective in decreasing rates of delay discounting in adults from medically underserved areas (ClinicalTrials.gov number NCT03501706).

Increasing Exercise Intensity: Teaching High-Intensity Interval Training to Individuals with Developmental Disabilities Using a Lottery Reinforcement System

Rates of overweight and obesity are above 70% in typically developing adults in the United States, with higher rates observed in individuals diagnosed with developmental disability (DD). Lottery reinforcement systems have been validated as effective exercise interventions for individuals with DD. Although high-intensity interval training (HIIT) has demonstrated health benefits, it has not been studied using individuals within this population. The purpose of this study was to implement a lottery reinforcement system to systematically increase heart rate (HR) during 30-min HIIT sessions with 3 adults with DD. Results demonstrated increases in HR from below to within the prescribed range in all 3 participants. For 1 participant, weight decreased by 10.8 pounds during the 9-week program. Implications include that lottery systems increase exercise intensity with adults with DD, that HR during exercise can be reliably controlled using a lottery system, and that similar programs may result in health benefits.

Delay discounting and household food purchasing decisions: The SHoPPER study

OBJECTIVE

Delay discounting is a neurocognitive trait that has been linked to poor nutritional health and obesity, but its role in specific dietary choices is unclear. This study tested whether individual differences in delay discounting are related to the healthfulness of household food purchases and reliance on nonstore food sources such as restaurants.

METHOD

The food purchases of 202 primary household food shoppers were objectively documented for 14 days through a food receipt collection and analysis protocol. The nutrient content of household food purchases was derived for each participant, and the overall diet quality (Healthy Eating Index-2015) and energy density (kcal/g) of foods and beverages were calculated. The proportion of energy from nonstore food sources was also derived. Delay discounting was assessed with a choice task featuring hypothetical monetary rewards.

RESULTS

Data were available for 12,624 foods and beverages purchased across 2,340 shopping episodes. Approximately 13% of energy was purchased from restaurants and other nonstore food sources. Steeper discounting rates were associated with lower overall Healthy Eating Index-2015 scores and a higher energy density (kcal/g) of purchased foods. Associations were attenuated but remained statistically significant when accounting for body mass index and sociodemographic variables. Discounting rates were unrelated to reliance on nonstore food sources or the energy density of purchased beverages.

CONCLUSIONS

Delay discounting is related to the healthfulness of food purchases among primary household shoppers. As food purchasing is a key antecedent of dietary intake, delay discounting may be a viable target in dietary and weight management interventions. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

How Thinking about the Future Affects Our Decisions in the Present: Effects of Time Orientation and Episodic Future Thinking on Responses to Health Warning Messages

Past research has consistently shown that people have the tendency to discount future outcomes. However, most health messages emphasize the long-term consequences of behaviors. Building upon past research on temporal discounting, time orientation, and construal level, the current research examines how dispositional time orientation (present and future) predicts health behavior intentions and the impact of situationally-activated future orientation through episodic future thinking on the persuasiveness of long-term health warnings. An online experiment was conducted with 946 African American smokers randomly assigned to engage in either future thinking or present thinking prior to viewing a series of graphic cigarette warning labels. Results suggested that a stronger present time orientation predicts greater intentions to smoke, while a stronger future time orientation predicts greater intentions to quit smoking. Additionally, future (vs. present) thinking significantly increased intentions to quit smoking through enhanced perceived self-efficacy for quitting smoking. Theoretical and practical implications of the findings are discussed.

Time Perspective and All-Cause Mortality: Evidence From the English Longitudinal Study of Ageing

BACKGROUND

Long-term future thinking has been associated with a range of favorable health behaviors. However, it is currently unclear whether this translates into an effect on morbidity and mortality.

PURPOSE

The goal of this study was to study the relationship between time perspective and all-cause mortality and to examine the role of health behavior in explaining this association.

METHODS

Participants (N = 9,949) aged 50 and over from the English Longitudinal Study of Ageing, a representative cohort of older English adults, estimated the length of their time horizon for financial planning (time perspective). Two thousand ninety-two deaths were recorded over a 9-year follow-up period (2002/2003-2012). Smoking, physical activity, and alcohol consumption were examined as factors that may underlie the time perspective-mortality link.

RESULTS

Our prospective survival analyses showed that those who tend to plan for longer periods experienced a significantly reduced risk of all-cause mortality (HR = 0.83; 95% confidence interval [CI]: [0.80, 0.87], p < .001 per 1 SD increase in future time perspective). This association remained after adjusting for baseline socioeconomic status and health (HR = 0.92; 95% CI: [0.88, 0.97], p < .001). The link between time perspective and mortality was observed across the gradient of financial circumstances and did not appear to be due to reverse causality. Healthy behavior among the more future orientated explained 34% of the link between time perspective and mortality.

CONCLUSIONS

Using a simply administered indicator of time perspective, this study suggests that a future-orientated time perspective may be an important predictor of reduced risk of death.

Exercise as a reward: Self-paced exercise perception and delay discounting in comparison with food and money

Exercise is an important health behavior. Expressed reasons for participation are often delayed outcomes i.e. health threats and benefits, but also enjoyment. However, we do not know how people evaluate exercise as a reward. The value of rewards diminish the longer we have to wait for them and the discounting effect can undermine decision-making. Here, we investigated delay-discounting of exercise perception and its valuation with time delays; we conducted self-paced exercise sessions on treadmill and compared the discounting rates of exercise (k_ex) with those of established rewards of food (k_fo) and money (k_m). Outcomes show, that young, moderately active participants (n = 70) preferred walking/running intensity with low to moderate cardiovascular strain and light perceived exertion. Delay discounting rates (k) indicated that exercise was discounted like other consumable rewards at the same rate as food and more rapidly than monetary rewards. Significant associations were detected of k_ex with preferred speed and with extrinsic exercise motivation. Exercise training (n = 16) reduced k_ex specifically, not affecting k_fo. Our studies show, that participants perceived and discounted self-paced walking/running like a consumable reward. Exercise discounting was quicker in individuals who preferred lower speeds being less physically active and exercise training reduced the decay rate of exercise specifically.

Successful weight loss initiation and maintenance among adolescents with overweight and obesity: does age matter?

Treatments for adolescents with overweight/obesity demonstrate mixed success, which may be due to a lack of consideration for developmental changes during this period. Potential developmental differences in weight loss motivations, weight maintenance behaviours and the role of parents in these efforts were examined in a sample of successful adolescent weight losers. Participants enrolled in the Adolescent Weight Control Registry (n = 49) self-reported demographic information and weight history, reasons for weight loss and weight control, weight loss approach and weight maintenance strategies, and perceived parental involvement with weight loss. Associations between age at weight loss initiation and the aforementioned factors were examined using linear and generalized regressions, controlling for highest z-BMI and sex. Adolescents who were older (≥16 years) at their weight loss initiation were more likely to report losing weight on their own (37.5% vs. 75%, P = 0.01) and reported greater responsibility for their weight loss and weight loss maintenance (P < 0.001) compared to younger adolescents. Younger age at weight loss initiation was associated with greater parental involvement (P = 0.005), whereas older age was associated with greater adolescent responsibility for the decision to lose weight (P = 0.002), the weight loss approach (P = 0.007) and food choices (P < 0.001). Findings suggest the importance of considering developmental differences in responsibility for weight loss and maintenance among adolescents with overweight/obesity.

Leveraging delay discounting for health: Can time delays influence food choice?

Delay discounting, the tendency to choose smaller immediate rewards over larger delayed rewards, is theorized to promote consumption of immediately rewarding but unhealthy foods at the expense of long-term weight maintenance and nutritional health. An untested implication of delay discounting models of decision-making is that selectively delaying access to less healthy foods may promote selection of healthier (immediately available) alternatives, even if they may be less desirable. The current study tested this hypothesis by measuring healthy versus regular vending machine snack purchasing before and during the implementation of a 25-s time delay on the delivery of regular snacks. Purchasing was also examined under a $0.25 discount on healthy snacks, a $0.25 tax on regular snacks, and the combination of both pricing interventions with the 25-s time delay. Across 32,019 vending sales from three separate vending locations, the 25-s time delay increased healthy snack purchasing from 40.1% to 42.5%, which was comparable to the impact of a $0.25 discount (43.0%). Combining the delay and the discount had a roughly additive effect (46.0%). However, the strongest effects were seen under the $0.25 tax on regular snacks (53.7%) and the combination of the delay and the tax (50.2%). Intervention effects varied substantially between vending locations. Importantly, time delays did not harm overall vending sales or revenue, which is relevant to the real-world feasibility of this intervention. More investigation is needed to better understand how the impact of time delays on food choice varies across populations, evaluate the effects of time delays on beverage vending choices, and extend this approach to food choices in contexts other than vending machines.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02359916.

The relationship between time perspective and self-regulatory processes, abilities and outcomes: a protocol for a meta-analytical review

INTRODUCTION

Both theoretical and empirical evidence suggests that time perspective is likely to influence self-regulatory processes and outcomes. Despite the theoretical and practical significance of such relations, the relationship between time perspective and self-regulatory processes and outcomes across different measures, samples and life domains, including health, has yet to be explored.

METHODS AND ANALYSIS

The proposed review will develop a taxonomy for classifying measures according to the self-regulatory process, ability or outcome that they are likely to reflect. Electronic scientific databases will be searched, along with relevant conference abstract booklets and citation lists. Additionally, a call for unpublished data will be submitted to relevant bodies. To be eligible for inclusion, studies must include a measure of time perspective and a measure of at least one self-regulatory process, ability and/ or outcome. Eligibility will not be restricted by publication date, language, type of sample or setting. The bivariate correlations will be extracted (or calculated) and submitted to a random-effects meta-analysis. The sample-weighted average effect size, heterogeneity, risk of bias and publication bias will be calculated, and the effects of categorical and continuous moderator variables on the effect sizes will be determined.

ETHICS AND DISSEMINATION

The proposed meta-analysis will synthesise previously conducted research; thus, ethical approval is not required. The findings will be submitted for publication in an international peer-reviewed journal and reported as part of the first author’s PhD thesis. The findings will also be disseminated to the research community and, where appropriate, to other interested parties through presentations at relevant academic and non-academic conferences.