Mind the Gap? An Intensive Longitudinal Study of Between-Person and Within-Person Intention-Behavior Relations

Within- and between-person associations of time-varying determinants with snacking in older adults: an ecological momentary assessment study

Promoting healthy snacking is important in addressing malnutrition, overweight and obesity among an ageing population. However, little is known about the factors underlying snacking behaviour in older adults. The present study aimed to explore within- and between-person associations between determinants (i.e. intention, visibility of snacks, social modelling and emotions) and snacking behaviours (i.e. decision to snack, health factor of the snack and portion size) in older adults (60+). Conducting a two-part intensive longitudinal design, data were analysed from forty-eight healthy older adults consisting of (1) an event-based self-report ecological momentary assessment (EMA) diary every time they had a snack and (2) a time-based EMA questionnaire on their phone five times per day. Analysis through generalised linear mixed models indicated that higher intention to snack healthily leads to healthier snacking while higher levels of social modelling and cheerfulness promote unhealthier choices within individuals. At the between-person level, similar results were found for intention and social modelling. Visibility of a snack increased portion size at both a within- and between-person level, while the intention to eat a healthy snack only increased portion size at the between-person level. No associations were found between the decision to snack and all determinants. This is the first study to investigate both within- and between-person associations between time-varying determinants and snacking in older adults. Such information holds the potential for incorporation into just-in-time adaptive interventions, allowing for personalised tailoring, more effective promotion of healthier snacking behaviours and thus pursuing the challenge of healthy ageing.

Associations Between Stress, Health Behaviors, and Quality of Life in Young Couples During the Transition to Survivorship: Protocol for a Measurement Burst Study

BACKGROUND

Cancer is a life-threatening, stressful event, particularly for young adults due to delays and disruptions in their developmental transitions. Cancer treatment can also cause adverse long-term effects, chronic conditions, psychological issues, and decreased quality of life (QoL) among young adults. Despite numerous health benefits of health behaviors (eg, physical activity, healthy eating, no smoking, no alcohol use, and quality sleep), young adult cancer survivors report poor health behavior profiles. Determining the associations of stress (either cancer-specific or day-to-day stress), health behaviors, and QoL as young adult survivors transition to survivorship is key to understanding and enhancing these survivors' health. It is also crucial to note that the effects of stress on health behaviors and QoL may manifest on a shorter time scale (eg, daily within-person level). Moreover, given that stress spills over into romantic relationships, it is important to identify the role of spouses or partners (hereafter partners) in these survivors' health behaviors and QoL.

OBJECTIVE

This study aims to investigate associations between stress, health behaviors, and QoL at both within- and between-person levels during the transition to survivorship in young adult cancer survivors and their partners, to identify the extent to which young adult survivors' and their partners' stress facilitates or hinders their own and each other's health behaviors and QoL.

METHODS

We aim to enroll 150 young adults (aged 25-39 years at the time of cancer diagnosis) who have recently completed cancer treatment, along with their partners. We will conduct a prospective longitudinal study using a measurement burst design. Participants (ie, survivors and their partners) will complete a daily web-based survey for 7 consecutive days (a "burst") 9 times over 2 years, with the bursts spaced 3 months apart. Participants will self-report their stress, health behaviors, and QoL. Additionally, participants will be asked to wear an accelerometer to assess their physical activity and sleep during the burst period. Finally, dietary intake (24-hour diet recalls) will be assessed during each burst via telephone by research staff.

RESULTS

Participant enrollment began in January 2022. Recruitment and data collection are expected to conclude by December 2024 and December 2026, respectively.

CONCLUSIONS

To the best of our knowledge, this will be the first study that determines the interdependence of health behaviors and QoL of young adult cancer survivors and their partners at both within- and between-person levels. This study is unique in its focus on the transition to cancer survivorship and its use of a measurement burst design. Results will guide the creation of a developmentally appropriate dyadic psychosocial or behavioral intervention that improves both young adult survivors' and their partners' health behaviors and QoL and potentially their physical health.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/53307.

Goal pursuit increases more after dietary success than after dietary failure: examining conflicting theories of self-regulation using ecological momentary assessment

BACKGROUND

Maintaining a healthy body weight and reaching long-term dietary goals requires ongoing self-monitoring and behavioral adjustments. How individuals respond to successes and failures is described in models of self-regulation: while cybernetic models propose that failures lead to increased self-regulatory efforts and successes permit a reduction of such efforts, motivational models (e.g., social-cognitive theory) make opposite predictions. Here, we tested these conflicting models in an ecological momentary assessment (EMA) context and explored whether effort adjustments are related to inter-individual differences in perceived self-regulatory success in dieting (i.e., weight management).

METHODS

Using linear mixed effects models, we tested in 174 diet-interested individuals whether current day dietary success or failure (e.g., on Monday) was followed by self-regulatory effort adjustment for the next day (e.g., on Tuesday) across 14 days. Success vs. failure was operationalized with two EMA items: first, whether food intake was higher vs. lower than usual and second, whether food intake was perceived as more vs. less goal-congruent than usual. Trait-level perceived self-regulatory success in dieting was measured on a questionnaire.

RESULTS

Intended self-regulatory effort increased more strongly after days with dietary success (i.e., eating less than usual / rating intake as goal-congruent) than after days with dietary failure (i.e., eating more than usual / rating intake as goal-incongruent), especially in those individuals with lower scores on perceived self-regulatory success in dieting.

CONCLUSIONS

Findings support mechanisms proposed by social-cognitive theory, especially in unsuccessful dieters. Thus, future dietary interventions could focus on preventing the decrease in self-regulatory effort after instances of dietary failures and thereby mitigate the potential risk that a single dietary failure initiates a downward spiral into unhealthy eating.

The relationship of within-individual and between-individual variation in mental health with bodyweight: An exploratory longitudinal study

BACKGROUND

Poor mental health is associated with obesity, but existing studies are either cross-sectional or have long time periods between measurements of mental health and weight. It is, therefore, unclear how small fluctuations in mental wellbeing within individuals predict bodyweight over short time periods, e.g. within the next month. Studying this could identify modifiable determinants of weight changes and highlight opportunities for early intervention.

METHODS

2,133 UK adults from a population-based cohort completed monthly mental health and weight measurements using a mobile app over a period of 6-9 months. We used random intercept regression models to examine longitudinal associations of depressive symptoms, anxiety symptoms and stress with subsequent weight. In sub-group analyses, we included interaction terms of mental health variables with baseline characteristics. Mental health variables were split into "between-individual" measurements (= the participant's median score across all timepoints) and "within-individual" measurements (at each timepoint, the difference between the participant's current score and their median).

RESULTS

Within-individual variation in depressive symptoms predicted subsequent weight (0.045kg per unit of depressive symptom severity, 95% CI 0.021-0.069). We found evidence of a moderation effect of baseline BMI on the association between within-individual fluctuation in depressive symptoms and subsequent weight: The association was only apparent in those with overweight/obesity, and it was stronger in those with obesity than those with overweight (BMI<25kg/m2: 0.011kg per unit of depressive symptom severity [95% CI -0.017 to 0.039]; BMI 25-29.9kg/m2: 0.052kg per unit of depressive symptom severity [95%CI 0.010-0.094kg]; BMI≥30kg/m2: 0.071kg per unit of depressive symptom severity [95%CI 0.013-0.129kg]). We found no evidence for other interactions, associations of stress and anxiety with weight, or for a reverse direction of association.

CONCLUSION

In this exploratory study, individuals with overweight or obesity were more vulnerable to weight gain following higher-than-usual (for that individual) depressive symptoms than individuals with a BMI<25kg/m2.

Biofeedback and Digitalized Motivational Interviewing to Increase Daily Physical Activity: Series of Factorial N-of-1 Randomized Controlled Trials Piloting the Precious App

BACKGROUND

Insufficient physical activity is a public health concern. New technologies may improve physical activity levels and enable the identification of its predictors with high accuracy. The Precious smartphone app was developed to investigate the effect of specific modular intervention elements on physical activity and examine theory-based predictors within individuals.

OBJECTIVE

This study pilot-tested a fully automated factorial N-of-1 randomized controlled trial (RCT) with the Precious app and examined whether digitalized motivational interviewing (dMI) and heart rate variability-based biofeedback features increased objectively recorded steps. The secondary aim was to assess whether daily self-efficacy and motivation predicted within-person variability in daily steps.

METHODS

In total, 15 adults recruited from newspaper advertisements participated in a 40-day factorial N-of-1 RCT. They installed 2 study apps on their phones: one to receive intervention elements and one to collect ecological momentary assessment (EMA) data on self-efficacy, motivation, perceived barriers, pain, and illness. Steps were tracked using Xiaomi Mi Band activity bracelets. The factorial design included seven 2-day biofeedback interventions with a Firstbeat Bodyguard 2 (Firstbeat Technologies Ltd) heart rate variability sensor, seven 2-day dMI interventions, a wash-out day after each intervention, and 11 control days. EMA questions were sent twice per day. The effects of self-efficacy, motivation, and the interventions on subsequent steps were analyzed using within-person dynamic regression models and aggregated data using longitudinal multilevel modeling (level 1: daily observations; level 2: participants). The analyses were adjusted for covariates (ie, within- and between-person perceived barriers, pain or illness, time trends, and recurring events).

RESULTS

All participants completed the study, and adherence to activity bracelets and EMA measurements was high. The implementation of the factorial design was successful, with the dMI features used, on average, 5.1 (SD 1.0) times of the 7 available interventions. Biofeedback interventions were used, on average, 5.7 (SD 1.4) times out of 7, although 3 participants used this feature a day later than suggested and 1 did not use it at all. Neither within- nor between-person analyses revealed significant intervention effects on step counts. Self-efficacy predicted steps in 27% (4/15) of the participants. Motivation predicted steps in 20% (3/15) of the participants. Aggregated data showed significant group-level effects of day-level self-efficacy (B=0.462; P<.001), motivation (B=0.390; P<.001), and pain or illness (B=-1524; P<.001) on daily steps.

CONCLUSIONS

The automated factorial N-of-1 trial with the Precious app was mostly feasible and acceptable, especially the automated delivery of the dMI components, whereas self-conducted biofeedback measurements were more difficult to time correctly. The findings suggest that changes in self-efficacy and motivation may have same-day effects on physical activity, but the effects vary across individuals. This study provides recommendations based on the lessons learned on the implementation of factorial N-of-1 RCTs.

A Mobile-Based Preventive Program for Young, Arabic-Speaking Asylum Seekers during the COVID-19 Pandemic in Germany: Design, Feasibility, and Implementation

BACKGROUND

A majority of individuals seeking asylum in Germany are living in collective housings and thus exposed to a higher risk of contagion during the COVID-19 pandemic.

OBJECTIVE

To test feasibility and efficacy of a culture-sensitive approach combining mobile app-based interventions and a face-to-face group intervention to improve knowledge about COVID-19 and promote vaccination readiness among collectively accommodated Arabic-speaking adolescents and young adults.

METHODS

We developed a mobile app that was composed of short video clips to explain the biological basis of COVID-19, demonstrate behavior to prevent transmission, and combat misconceptions and myths about vaccination. Explanations were given in a YouTube-like interview setting by a native Arabic-speaking physician. Elements of gamification (quizzes, rewards for solving test items) were also used. Consecutive videos and quizzes were presented over an intervention period of six weeks, the group intervention was scheduled as an add-on for half of participants in week 6. The manual of the group intervention was designed to provide actual behavior planning on the basis of the health action process approach. Sociodemographic information, mental health status, and knowledge about Covid-19 and available vaccines were assessed with questionnaire-based interviews at baseline and after six weeks. Interpreters assisted with the interviews in all cases.

RESULTS

Enrollment in the study proved to be very challenging as among other things, the housing facilities allowed contact with potentially eligible participants only during certain periods because of the pandemic situation. Also due to tightened contact restrictions, the face-to-face group interventions could not be held as planned. A total of 88 participants from 8 collective housing institutions were included in the study. 61 participants completed the full intake interview. Most participants had already been vaccinated at study enrollment (76.5%). They also yet claimed to comply with preventive measures to a very high extent (e.g., "always wearing masks" was indicated by 66% of participants), but practicing behavior that was not considered as effective against Covid-19 transmission was also frequently reported as a preventive measure (e.g., mouth rinsing). On the other hand, factual disease knowledge for COVID-19 was limited. Preoccupation with the information materials presented in the app steeply declined after study enrollment (e.g., 19% of participants watched the videos scheduled for week 3). Only 18 participants could be reached for the follow-up interview. Their COVID-19 disease knowledge did not shown to have increased after the intervention period (p=0.558).

CONCLUSIONS

The results indicate that vaccine uptake was high and seemed to be depending on organizational determinants for the target group. The current mobile app-based intervention demonstrated low feasibility, which might have been related to various obstacles faced during the delivery: Learning from mobile phone content based on short videos requires a basic understanding of biological and IT-aspects as well as sufficient literacy and a living situation enabling the practical application of the learned behavioral prevention strategies. Therefore, in case of future pandemics, transmission prevention in the specific target group should rely more on structural aspects instead on sophisticated psychological interventions.

CLINICALTRIAL

https://www.drks.de, identifier: DRKS00028825.

Autonomous motivation, goal-facilitating behaviours, and dietary goal progress in individuals transitioning to a veg*n diet: A longitudinal study

Previous studies have consistently shown that autonomous motivation - pursuing goals because one wants to, rather than has to - is associated with greater behaviour maintenance in the context of healthy eating, exercise, and diet maintenance. The present study used a 7-wave longitudinal design to examine how autonomous motivation is related to dietary goal progress in individuals (N = 222) transitioning to a veg*n (i.e., vegetarian or vegan) diet. We hypothesized that when people reported more autonomous motivation (compared to their own average) they would be more successful in reaching their dietary goals. We also explored the role of goal-facilitating behaviours in this process. We found no directional effects of relative autonomous motivation on goal progress or goal-facilitating behaviours, although the concurrent relations were significant. There were also no within-person effects of behaviours on progress. These findings shed light onto the relationship between autonomous motivation, behaviours, and goal progress both at the same time and over time, and highlight the importance of examining within-person fluctuations over time.

Perseverative cognition and health behaviours: exploring the role of intentions and perceived behavioural control

OBJECTIVE

Worry and rumination (Perseverative Cognition, PC) have been associated with health behaviours, but the underlying mechanisms are unknown. Given the role of physiological experiences on perceived behavioural control (PBC) and emotion regulation on intention-health behaviour relationships, we tested whether: PC prospectively predicts poorer health behaviours; PC moderates the relationship(s) between intentions/PBC and health behaviour, as well as whether the relationship between PC and health behaviour is mediated by intentions and PBC.

METHODS AND MEASURES

In a prospective design, 650 participants (mean age = 38.21 years; 49% female) completed baseline measures of intentions, PBC and PC (worry and rumination) and 590 (mean age = 38.68 years; 50% female) completed follow-up (Time 2) measures of health behaviours (physical activity, sleep, sedentary activity, unhealthy snacking) 1-week later.

RESULTS

Worry and rumination (at T1) predicted poorer sleep quality. Worry, but not rumination, moderated PBC-physical activity frequency relations. Consistent with mediation, the indirect paths from both worry and rumination, through PBC, to sleep quality and total sleep time were significant.

CONCLUSION

PC is associated with poorer sleep quality and PBC can play a mediating role in such relationships. Future research should further consider the role that PBC plays in PC-health behaviour relations.

Effects of behavioral performance, intrinsic reward value, and context stability on the formation of a higher-order nutrition habit: an intensive longitudinal diary study

Background

Habits drive many of our health behaviors in our daily lives. However, little is known about the relative contribution of different key factors for habit formation in real-world contexts. We examined the effects of behavioral performance, intrinsic reward value (operationalized as tastiness), and context stability on the formation of a higher-order nutrition habit.

Methods

Participants were recruited via mailing lists and posts on social media platforms. N = 199 participants (M_age = 37.10 years, SD = 13.00, 86.93% female) received an online intervention for building the higher-order habit of filling half of their plates with vegetables at dinner and completed one daily online survey for up to 56 days, including the assessment of habit strength, behavioral performance, intrinsic reward value, and context stability, providing a total of N = 6352 daily measurements. N = 189 participants (N = 4175 measurements) could be included in the primary analysis. Utilizing multilevel modeling, we analyzed the impact of behavioral performance, intrinsic reward value, and context stability, as well as their interaction effects, on habit strength on the next day.

Results

Habit strength significantly increased over time. This effect was strengthened in persons with high mean levels of behavioral performance. Furthermore, mean levels of behavioral performance, intrinsic reward value, and context stability were all positively related to mean levels of habit strength. There were no positive effects of daily intraindividual variations in the three examined factors on habit strength at the next day. There was an unexpected negative effect of daily behavioral performance on habit strength at the next day. We found little to no evidence for our expected and pre-registered interaction effects. In an additional exploratory analysis, there were positive effects of daily intraindividual variations in the three factors on habit strength at the same day.

Conclusions

We found that behavioral performance, intrinsic reward value, and context stability were all independent predictors of habit strength of a higher-order habit at the between-person level. However, we did not find the expected associations at the within-person level. Habit interventions should promote the consistent performance of the target behaviors in stable contexts.

Trial registration

https://aspredicted.org/blind.php?x=vu2cg4. Registered 28.04.2020.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12966-022-01343-8.

The Use of Mobile-Based Ecological Momentary Assessment (mEMA) Methodology to Assess Dietary Intake, Food Consumption Behaviours and Context in Young People: A Systematic Review

Mobile-based ecological momentary assessment (mEMA) offers a novel method for dietary assessment and may reduce recall bias and participant burden. This review evaluated mEMA methodology and the feasibility, acceptability and validity as a dietary assessment method in young people. Five databases were searched from January 2008 to September 2021 for studies including healthy young people aged 16–30 years and used mEMA for obtaining dietary intake data, food consumption behaviours and/or contextual factors. Data on the method used to administer mEMA, compliance with recording and validation were extracted. A total of 46 articles from 39 independent studies were included, demonstrating a wide variation in mEMA methods. Signal-contingent prompting (timed notification to record throughout the day) was used in 26 studies, 9 used event-contingent (food consumption triggered recordings), while 4 used both. Monitoring periods varied and most studies reported a compliance rate of 80% or more. Two studies found mEMA to be burdensome and six reported mEMA as easy to use. Most studies (31/39) reported using previously validated questions. mEMA appears to be a feasible and acceptable methodology to assess dietary intake and food consumption in near real time.

The Impact of Both Individual and Contextual Factors on the Acceptance of Personalized Dietary Advice

(1) Background: The aim of the current study is to investigate which between- and within-person factors influence the acceptance of personalized dietary advice. (2) Methods: A repeated measurements design was used in which 343 participants (M (SD) age = 48 (17.3), 49% female) filled out a baseline survey and started with nine repeated surveys. (3) Results: The results show that the acceptance of personalized dietary advice is influenced by both within-person and between-person factors. The acceptance is higher at lunch compared to breakfast and dinner, higher at home than out of home, higher at moments when individuals have a high intention to eat healthily, find weight control an important food choice motive and have a high healthy-eating self-efficacy. Moreover, the acceptance is higher when individuals do not see the eating context as a barrier and when individuals believe that personalized dietary advice has more benefits than risks. (4) Conclusions: Future behavioral interventions that use personalized dietary advice should consider the context as well as individual differences.

Plan pursuit in the context of daily fruit and vegetable consumption: The importance of cue detection and the execution of the planned behaviour for overall behaviour change

OBJECTIVES

In action planning interventions, individuals specify and link cues with behavioural responses to implement behaviour change. To date, not much is known about how and how much the detection of the planned cue (entering and identifying the planned situation) and the execution of the planned behaviour (behavioural response exactly as planned) contribute to overall behavioural changes (changes in target behaviour) achieved by individuals. Using data from an intervention on daily fruit and vegetable (FV) action planning, this study aimed to test whether individuals' cue detection and execution of the planned behaviour are positively related to overall FV intake.

DESIGN

Secondary data analyses examined diary data of the intervention condition of a randomized controlled trial. Ninety participants (80% female, aged 19-63 years) formed one FV plan and completed a 13-days post-intervention self-report diary assessing daily FV consumption and situational characteristics of each consumed FV serving. Based on these self-reports and participants' FV plan, day-to-day cue detection and the execution of the planned behaviour were coded.

METHODS

With two-level models, cue detection and the execution of the planned behaviour were examined as between- and within-person predictors of daily FV intake.

RESULTS

Higher between-person execution of the planned behaviour (+1.68 daily servings), higher-than-usual within-person cue detection (+0.46 daily servings), and higher-than-usual within-person execution of the planned behaviour (+0.29 daily servings) were associated with more overall FV intake.

CONCLUSIONS

Detecting planned cues (within-person) and executing the planned behaviour (between- and within-person) are important for overall FV intake.

Hand Washing and Related Cognitions Following a Brief Behavior Change Intervention During the COVID-19 Pandemic: a Pre-Post Analysis

Background

Effective hand washing (for at least 20 s, with water and soap) is one of the health behaviors protecting against infection transmissions. Behavior change interventions supporting the initiation and maintenance of hand washing are crucial to prevent infection transmissions. Based on the Health Action Process Approach, the aim of this research was to conduct a pre-post analysis of hand washing and related cognitions (i.e., intention, self-efficacy, self-monitoring), measured up to 100 days following an intervention.

Methods

A convenience sample of N = 123 participants (age: M = 23.96 years; SD = 5.82; 80% women) received a brief intervention (key behavior change techniques: information about health consequences of hand washing; action planning) and responded to daily diaries and questionnaires up to a 100-day follow-up. Two-level models were used to analyze data of n = 89 participants who provided longitudinal data.

Results

Hand washing and self-monitoring increased, whereas intention and self-efficacy decreased over time. Only self-monitoring was a consistent positive correlate of hand washing on a between-person level.

Conclusions

Hand washing and self-monitoring considerably increased over several weeks following the intervention. Future research testing the intervention against a control condition is needed to rule out that changes in behavior and cognitions might have been prompted by completing the daily diaries.

Trial Registration

German Clinical Trials Register; https://www.drks.de; registration number: DRKS00022067.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12529-021-10042-w.

Elena+ Care for COVID-19, a Pandemic Lifestyle Care Intervention: Intervention Design and Study Protocol

Background: The current COVID-19 coronavirus pandemic is an emergency on a global scale, with huge swathes of the population required to remain indoors for prolonged periods to tackle the virus. In this new context, individuals' health-promoting routines are under greater strain, contributing to poorer mental and physical health. Additionally, individuals are required to keep up to date with latest health guidelines about the virus, which may be confusing in an age of social-media disinformation and shifting guidelines. To tackle these factors, we developed Elena+, a smartphone-based and conversational agent (CA) delivered pandemic lifestyle care intervention. Methods: Elena+ utilizes varied intervention components to deliver a psychoeducation-focused coaching program on the topics of: COVID-19 information, physical activity, mental health (anxiety, loneliness, mental resources), sleep and diet and nutrition. Over 43 subtopics, a CA guides individuals through content and tracks progress over time, such as changes in health outcome assessments per topic, alongside user-set behavioral intentions and user-reported actual behaviors. Ratings of the usage experience, social demographics and the user profile are also captured. Elena+ is available for public download on iOS and Android devices in English, European Spanish and Latin American Spanish with future languages and launch countries planned, and no limits on planned recruitment. Panel data methods will be used to track user progress over time in subsequent analyses. The Elena+ intervention is open-source under the Apache 2 license (MobileCoach software) and the Creative Commons 4.0 license CC BY-NC-SA (intervention logic and content), allowing future collaborations; such as cultural adaptions, integration of new sensor-related features or the development of new topics. Discussion: Digital health applications offer a low-cost and scalable route to meet challenges to public health. As Elena+ was developed by an international and interdisciplinary team in a short time frame to meet the COVID-19 pandemic, empirical data are required to discern how effective such solutions can be in meeting real world, emergent health crises. Additionally, clustering Elena+ users based on characteristics and usage behaviors could help public health practitioners understand how population-level digital health interventions can reach at-risk and sub-populations.

Healthy eating strategies: Individually different or context-dependent?

Individuals can apply different healthy eating strategies to help them make healthy eating choices. Previous research showed that individuals differ in their preferred strategy, but also that a mix of strategies is often applied by a single person across contexts. The current research investigated the extent to which differences within an individual across contexts (i.e., meal moments, social environment and physical environment) predicted openness to healthy eating strategies in addition to personal predictors that differ between individuals (i.e., intrinsic motivation, self-efficacy, physical opportunity and social opportunity). A representative sample of the Dutch adult population was recruited (N = 892). The within-individual (contextual) predictors were measured nine times just before a meal moment over a period of three weeks, by means of a smartphone application. The between-individual (personal) predictors were administered with a baseline questionnaire. Exploratory factor analysis distinguished three healthy eating strategies: Increasing healthy foods, Limiting unhealthy foods and consuming Light products. A random intercept model, in which within-individual predictors and between-individual predictors were entered successively, showed that context matters for openness to all three strategies, but is most important for increasing healthy foods and least important for light products. Individuals are most open to increase healthy foods at dinner as compared to breakfast, whereas the opposite is true for limiting unhealthy foods and consuming light products. Eating at home is beneficial for openness to all three strategies and eating with others positively influences openness to increase healthy foods but has no effect on the other strategies. Insights gained from this research increase our understanding of an individual's openness to apply healthy eating strategies.

Study protocol: One plus one can be greater than two-Ecological momentary assessment for Black prostate cancer survivors and partners

Given that romantic partners play a pivotal role in patients' survivorship period, integrating partners into survivorship care and broadening the focus of behavioral interventions from the individual (survivor) to the survivor-partner dyad may make healthy lifestyle behaviors more easily adopted and potentially maintained. Understanding the role of dyadic processes in Black survivors is particularly important because their lifestyle behaviors are poor and they have higher cancer-specific and all-cause mortality. To develop an effective dyadic lifestyle behavior intervention for Black survivors, micro-level investigations of interactions between Black survivors and their partners are necessary to pinpoint how survivors and partners facilitate or hinder each other's lifestyle behaviors in their natural, everyday lives. Accordingly, the objective of the present study is to fill these gaps using ecological momentary assessment to eventually develop more effective lifestyle interventions for Black prostate cancer (PCa) survivors and partners. A total of 120 dyads (i.e., 240 individuals) who are Black adult survivors diagnosed with non-metastatic PCa and their romantic partners will be asked to complete four assessments per day for 14 consecutive days on a smartphone after an initial retrospective survey. Over the 14 days, participants will be asked to complete a brief survey regarding their lifestyle behaviors (physical activity, sedentariness and eating behaviors), contexts of lifestyle behaviors, stress, and coping. Physical activity and sedentary behavior will be assessed via accelerometer; eating behaviors will be assessed with the Automated Self-Administered 24-hour Dietary Assessment Tool. After completing the 14-day assessment, participants will be asked to complete a final retrospective survey. Results of the proposed study will inform the rigorous development of a theory-based dyadic lifestyle intervention in this vulnerable survivorship population with the ultimate goal to improve overall survival and reduce morbidities (for survivors) and reduce cancer incidence (for partners).

Context matters: Self-regulation of healthy eating at different eating occasions

Self-regulation plays an important role in healthy eating behaviors. The current research explores temporary fluctuations in self-regulation next to variations between individuals. In an online observational study, 892 participants (M^age  = 44.3, SD^age  = 12.7) monitored their self-regulation three times a week before a meal moment for 3 weeks. To analyze the data, a random intercept and slopes model was used, including variables on within-individual level (i.e. meal moment, tiredness, distractedness, social, and physical environment) and variables on between-individual level (i.e. self-efficacy, intrinsic motivation, and perception of social and physical opportunity). Self-regulation was found to be higher at breakfast compared with dinner (estimate = -0.08, p < .001), higher at home than out-of-home (estimate = -0.08, p < .001) and lower when individuals are more tired (estimate = 0.04, p < .001) and distracted (estimate = 0.07, p < .001). Moreover, self-regulation was higher for individuals with higher levels of intrinsic motivation (estimate = 0.19, p < .001) and self-efficacy (estimate = 0.41, p < .001). Insights from this research advance our knowledge regarding temporal influences on self-regulation and can provide input for behavior change tools such as personalized dietary advice.

Do socio-structural factors moderate the effects of health cognitions on COVID-19 protection behaviours?

OBJECTIVE

Adherence to protection behaviours remains key to curbing the spread of the SARS-CoV-2 virus that causes COVID-19, but there are substantial differences in individual adherence to recommendations according to socio-structural factors. To better understand such differences, the current research examines whether relationships between health cognitions based on the Reasoned Action Approach (RAA) and eight COVID-19 protection behaviours vary as a function of participant-level socio-structural factors.

METHODS

Within-person design with behaviours nested within participants in a two-wave online survey (one week delay) conducted during the UK national lockdown in April 2020. A UK representative sample of 477 adults completed baseline measures from the RAA plus perceived susceptibility and past behaviour for eight protection behaviours, and self-reported behaviour one week later. Moderated hierarchical linear models with cross-level interactions were used to test moderation of health cognitions by socio-structural factors (sex, age, ethnicity, deprivation).

RESULTS

Sex, ethnicity and deprivation moderated the effects of health cognitions on protection intentions and behaviour. For example, the effects of injunctive norms on intentions were stronger in men compared to women. Importantly, intention was a weaker predictor of behaviour in more compared to less deprived groups. In addition, there was evidence that perceived autonomy was a stronger predictor of behaviour in more deprived groups.

CONCLUSION

Socio-structural variables affect how health cognitions relate to recommended COVID-19 protection behaviours. As a result, behavioural interventions based on social-cognitive theories might be less effective in participants from disadvantaged backgrounds.

Environmental Issues Are Health Issues

Abstract. Increasing demands on ecosystems, decreasing biodiversity, and climate change are among the most pressing environmental issues of our time. As changing weather conditions are leading to increased vector-borne diseases and heat- and flood-related deaths, it is entering collective consciousness: environmental issues are human health issues. In public health, the field addressing these issues is known as environmental health. This field addresses both the effects people have on their environment as well as the effects of the environment on people. Psychology, as a discipline concerned with explaining, predicting, and changing behavior has much to contribute to these issues because human behavior is key in promoting environmental health. To date, however, an integrative view of environmental health in psychology is lacking, hampering urgently needed progress. In this paper, we review how the environment and human health are intertwined, and that much can be gained through a systemic view of environmental health in psychology. Based on a review of the literature, we suggest that psychologists unite efforts to promote an integrative science and practice of environmental health psychology, and jointly address environmental-health related behavior. The research agenda for this field will include integrating behavior change theory and intervention approaches. Thereby, psychology can potentially make an important contribution to sustained environmental health for generations to come.

Attitude stability as a moderator of the relationships between cognitive and affective attitudes and behaviour

Temporal stability is assumed to be an important basis for attitudes being strong predictors of behaviour, but this notion has been little tested. The current research reports tests of temporal stability in moderating the attitude-behaviour relationship, specifically in relation to cognitive attitude (i.e., evaluation implied by cognitions about an attitude object) and affective attitude (i.e., evaluation implied by feelings about the attitude object). In three prospective studies (Study 1: physical activity, N = 909; Study 2: multiple health behaviours, N = 281; Study 3: smoking initiation, N = 3,371), temporal stability is shown to moderate the cognitive and affective attitudes to subsequent behaviour relationship in two-, three-, and four-wave designs utilizing between- (Studies 1 and 3) and within-participants (Study 2) analyses and controlling for past behaviour. Effects were more consistent for affective attitudes (when affective and cognitive attitudes were considered simultaneously and past behaviour controlled). Moderation effects were attenuated, but remained significant, in three- and four-wave compared with two-wave designs. The findings underline the role of temporal stability as an indicator of strength and confirm the relative importance of affective over cognitive (components of) attitudes for predicting behaviour.

Too many zeros and/or highly skewed? A tutorial on modelling health behaviour as count data with Poisson and negative binomial regression

Background: Dependent variables in health psychology are often counts, for example, of a behaviour or number of engagements with an intervention. These counts can be very strongly skewed, and/or contain large numbers of zeros as well as extreme outliers. For example, 'How many cigarettes do you smoke on an average day?' The modal answer may be zero but may range from 0 to 40+. The same can be true for minutes of moderate-to-vigorous physical activity. For some people, this may be near zero, but take on extreme values for someone training for a marathon. Typical analytical strategies for this data involve explicit (or implied) transformations (smoker v. non-smoker, log transformations). However, these data types are 'counts' (i.e. non-negative whole numbers) or quasi-counts (time is ratio but discrete minutes of activity could be analysed as a count), and can be modelled using count distributions - including the Poisson and negative binomial distribution (and their zero-inflated and hurdle extensions, which alloweven more zeros). Methods: In this tutorial paper I demonstrate (in R, Jamovi, and SPSS) the easy application of these models to health psychology data, and their advantages over alternative ways of analysing this type of data using two datasets - one highly dispersed dependent variable (number of views on YouTube, and another with a large number of zeros (number of days on which symptoms were reported over a month). Results: The negative binomial distribution had the best fit for the overdispersed number of views on YouTube. Negative binomial, and zero-inflated negative binomial were both good fits for the symptom data with over-abundant zeros. Conclusions: In both cases, count distributions provided not just a better fit but would lead to different conclusions compared to the poorly fitting traditional regression/linear models.

Compensation and transfer effects of eating behavior change in daily life: Evidence from a randomized controlled trial

Pursuing specific eating goals may lead to the adoption of other healthy behaviors (transfer) or compensation with unhealthy behaviors. Previous research has mostly investigated such processes using non-experimental studies focusing on interindividual differences. To investigate transfer or compensation of eating behavior in daily life, we analyzed data from a 2 (eating goal: more fruit and vegetables [FV] vs. fewer unhealthy snacks) x 2 (intervention vs. control group) factorial randomized trial. Adopting a within-person perspective, we studied potential transfer and compensation 1) between different eating behaviors and physical activity (PA), and 2) in response to an eating behavior change intervention. Participants (N = 203) received either goals to increase FV intake or decrease unhealthy snack intake and completed a daily e-diary. Eating more unhealthy snacks predicted 0.16 less FV portions (β = -0.07; p < 0.001) and 18% less unhealthy snack intake the next day (p < 0.001). Eating more FV predicted 0.42 less FV portions the next day (β = -0.07; p < 0.001). Participants with the FV eating goal intervention decreased unhealthy snacks (p = 0.012) and PA (p = 0.019) by 8% compared to controls, respectively. Similar but non-significant patterns were observed for participants with the decreasing unhealthy snack goal intervention (p > 0.05). Results indicated both compensation and transfer processes in daily life. Relationships mostly occur within the same behavior and rather support compensatory effects. In turn, a behavior change intervention to promote FV intake potentially enhances non-assigned eating behaviors, indicating transfer, but may lower PA.

Immediate effects of a very brief planning intervention on fruit and vegetable consumption: A randomized controlled trial

Action planning interventions can effectively promote fruit and vegetable (FV) consumption, but not much is known about the day-to-day translation of intervention planning into action. In this randomized controlled trial, immediate intervention effects of a very brief planning intervention on FV consumption during the following 13 days were investigated. After a 13-day pre-intervention diary, N = 206 participants (aged 19-66 years) were randomly allocated to a waiting-list control condition or a planning condition, where they formed one FV plan. Participants from both conditions completed a 13-day post-intervention diary. Self-reported daily FV consumption, FV-specific self-efficacy, and action control were assessed. Segmented linear mixed models estimating a discrete change (i.e. "jump") between diary phases showed a positive "jump" of FV intake and self-efficacy in the planning condition when compared to the control condition. For action control, such effects were not observed. Changes in study variables throughout the post-intervention phase did not differ between both conditions. Present findings extend previous evidence on action planning interventions by showing that increases in self-regulatory (i.e. self-efficacy) and behavioral (i.e. FV intake) outcomes can occur very rapidly and already on the first day for which behavioral increases were planned.

Signs of Warning: Do Health Warning Messages on Sweets Affect the Neural Prefrontal Cortex Activity?

In the global attempt to combat rising obesity rates, the introduction of health warning messages on food products is discussed as one possible approach. However, the perception of graphical health warning messages in the food context and the possible impact that they may have, in particular at the neuronal level, have hardly been studied. Therefore, the aim of this explorative study was to examine consumers’ reactions (measured as neuronal activity and subjective reporting) of two different types of graphical health warning messages on sweets compared to sweets without warning messages. One type used the red road traffic stop sign as graphical information (“Stop”), while the other one used shocking pictures (“Shock”), an approach similar to the images on cigarette packages. The neural response of 78 participants was examined with the neuroimaging technique functional near-infrared spectroscopy (fNIRS). Different hemodynamic responses in the orbitofrontal cortex (OFC), the frontopolar cortex (FOC), and the dorsolateral prefrontal cortex (dlPFC) were observed, regions which are associated with reward evaluation, social behavior consequences, and self-control. Further, the health warning messages were actively and emotionally remembered by the participants. These findings point to an interesting health information strategy, which should be explored and discussed further.

Compensatory health beliefs and unhealthy snack consumption in daily life

Compensatory health beliefs (CHBs) are beliefs that an unhealthy behavior (unhealthy eating) can be compensated for by engaging in a healthy behavior (physical activity). Previous research focused on CHBs as rather stable beliefs (trait). Some studies indicated that situation-specific CHBs (state) might be important in situations, in which people are confronted with an unhealthy snack. This study aims to investigate the association between CHBs and unhealthy snack consumption in daily life with a special focus on the distinction between trait and state CHBs. Overall, N = 45 participants (66.7% female; age: 18-45 years, M = 21.9) received a link to an online questionnaire five times daily for seven consecutive days (n = 1575 possible diary entries). They reported unhealthy snack consumption, state and trait CHBs concerning the compensation with subsequent eating behavior and physical activity. The results showed that trait and state CHBs were significantly positively related to unhealthy snack consumption in daily life. Different effects appeared for CHBs concerning the compensation with subsequent eating behavior compared to the compensation with physical activity. This study demonstrates that both, state and trait CHBs are important for unhealthy snack consumption in daily life. Findings emphasize the need for further daily diary approaches to understand the temporal sequence of state CHBs that could further explain the use of CHBs as a maladaptive strategy for unhealthy eating.

An 8-Week Study on Social-Cognitive Variables for Physical Activity and Fruit and Vegetable Intake: Are there Stage Transitions?

BACKGROUND

Health behavior change can be modelled in terms of stages, and outcomes of transitions between stages can be categorized into progression, regression, and stagnation. Based on the Health Action Process Approach this study tested whether changes in social-cognitive variables are associated with transitions between stages regarding physical activity (PA) and fruit and vegetable intake (FVI).

METHODS

N = 132 participants (M = 50.86 years, SD = 13.17, 61.4% women) were assessed at baseline and 8 weeks later. Data were analysed using multivariate analyses of variance (MANOVA) and post-hoc comparisons.

RESULTS

Changes in motivational self-efficacy (η²  = 0.081), maintenance self-efficacy (η²  = 0.119), and recovery self-efficacy (η²  = 0.049) as well as positive outcome expectancies (η²  = 0.070), negative outcome expectancies (η²  = 0.055), and coping planning (η²  = 0.065) were associated with FVI stage progression. For PA, changes were not associated with stage progression.

CONCLUSION

To facilitate behavior change effectively, at least for FVI, it is essential to consider underlying mechanisms such as several aspects of self-efficacy in performing the desired health behaviors, outcome expectations, and planning how to overcome barriers. Additionally, the adoption of a stage approach may be a useful starting point to develop stage-matched interventions.

Ambulatory Assessment for Physical Activity Research: State of the Science, Best Practices and Future Directions

Technological and digital progress benefits physical activity (PA) research. Here we compiled expert knowledge on how Ambulatory Assessment (AA) is utilized to advance PA research, i.e., we present results of the 2nd International CAPA Workshop 2019 "Physical Activity Assessment - State of the Science, Best Practices, Future Directions" where invited researchers with experience in PA assessment, evaluation, technology and application participated. First, we provide readers with the state of the AA science, then we give best practice recommendations on how to measure PA via AA and shed light on methodological frontiers, and we furthermore discuss future directions. AA encompasses a class of methods that allows the study of PA and its behavioral, biological and physiological correlates as they unfold in everyday life. AA includes monitoring of movement (e.g., via accelerometry), physiological function (e.g., via mobile electrocardiogram), contextual information (e.g., via geolocation-tracking), and ecological momentary assessment (EMA; e.g., electronic diaries) to capture self-reported information. The strengths of AA are data assessment that near realtime, which minimizes retrospective biases in real-world settings, consequentially enabling ecological valid findings. Importantly, AA enables multiple assessments across time within subjects resulting in intensive longitudinal data (ILD), which allows unraveling within-person determinants of PA in everyday life. In this paper, we show how AA methods such as triggered e-diaries and geolocation-tracking can be used to measure PA and its correlates, and furthermore how these findings may translate into real-life interventions. In sum, AA provides numerous possibilities for PA research, especially the opportunity to tackle within- subject antecedents, concomitants, and consequences of PA as they unfold in everyday life. In-depth insights on determinants of PA could help us design and deliver impactful interventions in real-world contexts, thus enabling us to solve critical health issues in the 21st century such as insufficient PA and high levels of sedentary behavior.

Why We Eat What We Eat: Assessing Dispositional and In-the-Moment Eating Motives by Using Ecological Momentary Assessment

Background

Why do we eat? Our motives for eating are diverse, ranging from hunger and liking to social norms and affect regulation. Although eating motives can vary from eating event to eating event, which implies substantial moment-to-moment differences, current ways of measuring eating motives rely on single timepoint questionnaires that assess eating motives as situation-stable dispositions (traits). However, mobile technologies including smartphones allow eating events and motives to be captured in real time and real life, thus capturing experienced eating motives in-the-moment (states).

Objective

This study aimed to examine differences between why people think they eat (trait motives) and why they eat in the moment of consumption (state motives) by comparing a dispositional (trait) and an in-the-moment (state) assessment of eating motives.

Methods

A total of 15 basic eating motives included in The Eating Motivation Survey (ie, liking, habit, need and hunger, health, convenience, pleasure, traditional eating, natural concerns, sociability, price, visual appeal, weight control, affect regulation, social norms, and social image) were assessed in 35 participants using 2 methodological approaches: (1) a single timepoint dispositional assessment and (2) a smartphone-based ecological momentary assessment (EMA) across 8 days (N=888 meals) capturing eating motives in the moment of eating. Similarities between dispositional and in-the-moment eating motive profiles were assessed according to 4 different indices of profile similarity, that is, overall fit, shape, scatter, and elevation. Moreover, a visualized person × motive data matrix was created to visualize and analyze between- and within-person differences in trait and state eating motives.

Results

Similarity analyses yielded a good overall fit between the trait and state eating motive profiles across participants, indicated by a double-entry intraclass correlation of 0.52 (P<.001). However, although trait and state motives revealed a comparable rank order (r=0.65; P<.001), trait motives overestimated 12 of 15 state motives (P<.001; d=1.97). Specifically, the participants assumed that 6 motives (need and hunger, price, habit, sociability, traditional eating, and natural concerns) are more essential for eating than they actually were in the moment (d>0.8). Furthermore, the visualized person × motive data matrix revealed substantial interindividual differences in intraindividual motive profiles.

Conclusions

For a comprehensive understanding of why we eat what we eat, dispositional assessments need to be extended by in-the-moment assessments of eating motives. Smartphone-based EMAs reveal considerable intra- and interindividual differences in eating motives, which are not captured by single timepoint dispositional assessments. Targeting these differences between why people think they eat what they eat and why they actually eat in the moment may hold great promise for tailored mobile health interventions facilitating behavior changes.

Social cognitions and smoking behaviour: Temporal resolution matters

Objectives Health behaviour theories outline how cognitions predict behaviours, but rarely specify the temporal relation between cognitions and behaviours. It is not known whether these predictive relationships vary depending on temporal resolution or whether the relative influence of cognitions varies with measurement schedules. The current exploratory study therefore investigates whether the associations between behavioural cognitions (self-efficacy, intention, and risk perception) and smoking vary when measured momentarily, at day level, or using the more common baseline-follow-up design. Design EMA study involving 36 continuing smokers over 17 days. Participants logged cigarettes and reported their cognitions at baseline, daily (evening), and in response to momentary surveys. Methods Random-effects models were used to compare the effects of cognitions measured at different time points on (1) the number of cigarettes smoked daily and (2) the time interval until the next cigarette smoked. Results Self-efficacy and risk perception measured at baseline significantly predicted cigarettes smoked each day, but this effect became non-significant when daily measurements of cognitions were included in the model. Momentary smoking behaviour was predicted by momentary measurements of risk perception, with no significant effects of social cognitions at baseline. Conclusions Relationships between cognitions and behaviours vary according to the temporal resolution of the measurement schedule. Ensuring that the temporal resolution of assessment is appropriate for the temporal dynamics of the behaviour being assessed is important. Future research is needed to investigate the potential for leveraging specific cognitive processes depending on temporal importance in order to increase health-promoting behaviours. Statement of contribution What is already known on this subject? Social cognitions including intentions, risk perception, and self-efficacy have been observed to predict smoking. Little is known about the role of time in the cognition-behaviour relationship. Cognitions have been observed to fluctuate, but instability is typically not considered in research design. What does this study add? Daily measurement of social cognitions predicts behaviour better than measurements taken at baseline. Momentary smoking behaviour is predicted by momentary cognitions at the intra-individual level. Temporal resolution of measurement should be considered when investigating cognition-behaviour relationships.

Do Daily Fluctuations in Psychological and App-Related Variables Predict Engagement With an Alcohol Reduction App? A Series of N-Of-1 Studies

BACKGROUND

Previous studies have identified psychological and smartphone app-related predictors of engagement with alcohol reduction apps at a group level. However, strategies to promote engagement need to be effective at the individual level. Evidence as to whether group-level predictors of engagement are also predictive for individuals is lacking.

OBJECTIVE

The aim of this study was to examine whether daily fluctuations in (1) the receipt of a reminder, (2) motivation to reduce alcohol, (3) perceived usefulness of the app, (4) alcohol consumption, and (5) perceived lack of time predicted within-person variability in the frequency and amount of engagement with an alcohol reduction app.

METHODS

We conducted a series of observational N-of-1 studies. The predictor variables were measured twice daily for 28 days via ecological momentary assessments. The outcome variables were measured through automated recordings of the participants' app screen views. A total of nine London-based adults who drank alcohol excessively and were willing to set a reduction goal took part. Each participant's dataset was analyzed separately using generalized additive mixed models to derive incidence rate ratios (IRRs) for the within-person associations of the predictor and outcome variables. Debriefing interviews, analyzed using thematic analysis, were used to contextualize the findings.

RESULTS

Predictors of the frequency and amount of engagement differed between individuals, and for the variables 'perceived usefulness of the app' and 'perceived lack of time', the direction of associations also differed between individuals. The most consistent predictors of within-person variability in the frequency of engagement were the receipt of a daily reminder (IRR=1.80-3.88; P<.05) and perceived usefulness of the app (IRR=0.82-1.42; P<.05). The most consistent predictors of within-person variability in the amount of engagement were motivation to reduce alcohol (IRR=1.67-3.45; P<.05) and perceived usefulness of the app (IRR=0.52-137.32; P<.05).

CONCLUSIONS

The utility of the selected psychological and app-related variables in predicting the frequency and amount of engagement with an alcohol reduction app differed at the individual level. This highlights that key within-person associations may be masked in group-level designs and suggests that different strategies to promote engagement may be required for different individuals.

Socioeconomic Status Moderates the Effects of Health Cognitions on Health Behaviors within Participants: Two Multibehavior Studies

Background

Socioeconomic differences in health-related behaviors are a major cause of health inequalities. However, the mechanisms (mediation/moderation) by which socioeconomic status (SES) affects health behavior are a topic of ongoing debate.

Purpose

Current research on SES as moderator of the health cognitions–health behavior relation is inconsistent. Previous studies are limited by diverse operationalizations of SES and health behaviors, demographically narrow samples, and between-person designs addressing within-person processes. This paper presents two studies addressing these shortcomings in a within-person multibehavior framework using hierarchical linear models.

Methods

Two online studies, one cross-sectional and one 4 week longitudinal, assessed 1,005 (Study 1; Amazon MTurk; USA only) and 1,273 participants (Study 2; Prolific; international). Self-reports of multiple SES indicators (education, income, occupation status; ZIP code in Study 1), health cognitions (from the theory of planned behavior), and measures of six health behaviors were taken. Multilevel models with cross-level interactions tested whether the within-person relationships between health cognitions and behaviors differed by between-person SES.

Results

Education significantly moderated intention-behavior and attitude-behavior relationships in both studies, with more educated individuals showing stronger positive relationships. In addition, ZIP-level SES (Study 1) moderated attitude-behavior effects such that these relationships were stronger in participants living in areas with higher SES.

Conclusions

Education appears to be an important resource for the translation of intentions and attitudes into behavior. Other SES indicators showed less consistent effects. This has implications for interventions aiming at increasing intentions to change health behaviors, as some interventions might inadvertently increase health inequalities.

It's Time to Think about Time in Health Psychology

This position paper addresses the need for stronger theorizing on temporal matters in health psychology. Too few theories in health psychology address temporal matters in the specified psychological phenomena, their relationships, and the explanation for these relationships. This might lead to underestimating existing relationships between constructs over time or missing out on opportunities for advancing our knowledge with regard to dynamic developments of the phenomena of interest. Examples of existing theories and approaches addressing temporal matters in health psychology are provided. Further, drawing from other disciplines, examples of methodological and conceptual approaches are outlined that offer directions on how to optimize our theories with regard to temporal matters. This might start with including time-related theoretical considerations to the definition of psychological concepts already in cross-sectional research and might reach as far as developing dynamic theories for capturing and changing phenomena of interest in real life. Challenges and opportunities of theorizing about temporal matters in health psychology are addressed.

Challenges and solutions for N-of-1 design studies in health psychology

Theories of behaviour change and health behaviour change interventions are most often evaluated in between-person designs. However, behaviour change theories apply to individuals not groups and behavioural interventions ultimately aim to achieve within-person rather than between-group change. Within-person methodology, such as N-of-1 (also known as single case design), can circumvent this issue, though has multiple design-specific challenges. This paper provides a conceptual review of the challenges and potential solutions for undertaking N-of-1 studies in health psychology. Key challenges identified include participant adherence to within-person protocols, carry-over and slow onset effects, suitability of behaviour change techniques for evaluation in N-of-1 experimental studies, optimal allocation sequencing and blinding, calculating power/sample size, and choosing the most suitable analysis approach. Key solutions include involving users in study design, employing recent technologies for unobtrusive data collection and problem solving by design. Within-person designs share common methodological requirements with conventional between-person designs but require specific methodological considerations. N-of-1 evaluation designs are appropriate for many though not all types of interventions. A greater understanding of patterns of behaviours and factors influencing behaviour change at the within-person level is required to progress health psychology into a precision science. Video abstract: Supplementary Material 1.

Automatic processes and self-regulation of illness

Research on the Commonsense Self-Regulation Model has emphasised reflective/conscious perceptual processes regarding illness threat (beliefs about symptoms, consequences, timeline, and curability) in predicting and changing coping behaviours. Understanding of illness self-regulation and avenues for intervention might be enriched by consideration of automatic processes that influence the recognition and identification of illness, response to illness, and ongoing management. This article adopts an integrative approach to (1) outline the theoretical importance of implicit processes in patients' self-regulation of illness and methods to study them; (2) review research evidence for these processes, including interventions tested to modify them; and (3) outline avenues for future research. A substantial body of research on implicit processes (cognitive bias and interpretational bias) in illness maintenance in chronic illness has recently been extended to detection and interpretation of acute illness and new perspectives relating to the self-system. There is encouraging evidence that cognitive accessibility of coping and implicit attitudes may impact upon coping behaviours. Procedures that strategically automatise coping responses and create habits have considerable promise. We outline an agenda for future research in which health psychology accepts the challenge posed by the interplay of the reflective and associative systems in promoting effective self-regulation of illness.

Food product health warnings promote dietary self-control through reductions in neural signals indexing food cue reactivity

Modern societies are replete with palatable food cues. A growing body of evidence suggests that food cue exposure activates conditioned appetitive physiological and psychological responses that may override current metabolic needs and existing eating goals, such as the desire to maintain a healthy diet. This conditioned response results in unhealthy dietary choices and is a contributing factor in the current obesity epidemic. Prime based obesity prevention measures such as health warnings at point-of-sale or on product packaging may have the potential to counteract the influence of the obesogenic environment at the crucial moment when people make food purchasing or consumption decisions. Existing research into the efficacy of these intervention strategies has predominantly employed self-report and population level measures, and little evidence exists to support the contention that these measures counteract food cue reactivity at the time of decision making. Using a dietary self-control priming paradigm, we demonstrated that brief exposure to food product health warnings enhanced dietary self-control. Further, we analysed electroencephalographic correlates of selective attention and food cue evoked craving (N1, P3, LPP) to show that health warning exposure reduced the automatic appetitive response towards palatable food cues. These findings contribute to existing evidence that exogenous information can successfully prime latent goals, and substantiate the notion that food product health warnings may provide a new avenue through which to curb excessive energy intake and reduce rising obesity rates.

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Food product health warnings successfully promote dietary self-control.

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ERP components P3 and LPP sensitive to food characteristics and health warnings

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LPP amplitudes also directly predict dietary self-control.

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Health warnings useful to reduce appetitive food responses in obesity prevention

Transfer or Compensation?

Abstract. This study tested the effects of exercise on eating behavior. The transfer hypothesis proposes that exercise leads to a generalization of healthy behavior and therefore an improved diet. The compensation hypothesis assumes that exercise leads to increased caloric intake in order to “compensate” for the energy expenditure. We tested these hypotheses for actual as well as imagined exercise. Female university employees or students (N = 227) were randomly assigned to three experimental groups: actual exercise vs. imagined exercise vs. control. After baseline data had been obtained, the participants engaged in a 5-minute experimental task and were then left alone with unhealthy snacks. Participants who had imagined themselves exercising (M = 101 kcal, SD = 128 kcal) consumed significantly fewer calories than did controls (M = 129 kcal, SD = 142 kcal), consistent with a transfer effect. Participants who had engaged in actual exercise, but had been distracted from thinking about exercise, consumed quantities (M = 127 kcal, SD = 111 kcal) similar to those consumed by controls. This study suggests that transfer effects are underpinned by psychological processes, such as goal activation, which should be investigated in the future.

Healthy food choices are happy food choices: Evidence from a real life sample using smartphone based assessments

Research suggests that “healthy” food choices such as eating fruits and vegetables have not only physical but also mental health benefits and might be a long-term investment in future well-being. This view contrasts with the belief that high-caloric foods taste better, make us happy, and alleviate a negative mood. To provide a more comprehensive assessment of food choice and well-being, we investigated in-the-moment eating happiness by assessing complete, real life dietary behaviour across eight days using smartphone-based ecological momentary assessment. Three main findings emerged: First, of 14 different main food categories, vegetables consumption contributed the largest share to eating happiness measured across eight days. Second, sweets on average provided comparable induced eating happiness to “healthy” food choices such as fruits or vegetables. Third, dinner elicited comparable eating happiness to snacking. These findings are discussed within the “food as health” and “food as well-being” perspectives on eating behaviour.

Health Behavior Change in Older Adults: Testing the Health Action Process Approach at the Inter- and Intraindividual Level

BACKGROUND

Health behavior change theories usually claim to be universally and individually applicable. Most research has tested behavior change theories at the interindividual level and within young-to-middle-aged populations. However, associations at the interindividual level can differ substantially from associations at the intraindividual level. This study examines the applicability of the Health Action Process Approach (HAPA) at the inter- and the intraindividual level among older adults.

METHODS

Two intensive longitudinal studies examined the HAPA model covering two different health behaviors and two different time spans: Study 1 (physical activity, N = 52 × 6 monthly observations) and Study 2 (medication adherence, N = 64 × 30 daily observations). The HAPA constructs (risk awareness, outcome expectancy, self-efficacy, intention, action planning, action control), and self-reported behaviors were assessed.

RESULTS

Overall, at the interindividual level, results of both studies largely confirmed the associations specified by the HAPA. At the intraindividual level, results were less in line with the HAPA. Only action control emerged as consistent predictor of behavior.

CONCLUSIONS

This study emphasises the importance of examining health behavior change theories at both, the inter- and the intraindividual level.

Using Smartphone-Based Support Groups to Promote Healthy Eating in Daily Life: A Randomised Trial

BACKGROUND

Although many people intend to eat healthily, they often fail to do so. We report the first randomised trial testing whether smartphone-based support groups can enhance healthy eating.

METHODS

Adults (N = 203) were randomised to the support or control condition (information), and to one of two eating goals (increasing fruit and vegetable/decreasing unhealthy snack consumption). After baseline, participants received information on their assigned eating goal, and completed a 13-day electronic diary. During Days 4-10, support participants were asked to support each other in achieving their eating goal in smartphone-based groups. The primary outcome was daily servings of fruit/vegetables or unhealthy snacks. Maintenance of intervention effects was assessed on Days 11-13, and at 1-month and 2-month follow-ups.

RESULTS

Support participants showed a gradual increase in healthy eating over time, and ate 1.4 fruits and vegetables more, 95% CI [0.3, 2.6], or 0.8 unhealthy snacks less, 95% CI [-1.4, -0.2] than controls on Day 10. Most effects were not maintained at follow-ups.

CONCLUSIONS

Smartphone-based groups can promote fruit and vegetable consumption and decrease unhealthy snack intake. This study extends previous findings of the benefits of support groups, and sheds light on the temporal dynamics of behavior change.

Which characteristics of planning matter? Individual and dyadic physical activity plans and their effects on plan enactment

OBJECTIVE

Past research supports individual planning as an effective intervention strategy to increase physical activity in individuals. A similar strategy, dyadic planning, adds a planning partner who supports an individual's planning processes. Whether the two planning formats differ in terms of participants' entered plan content and whether and how different content characteristics are linked to plan enactment remains unknown. By investigating the content of generated plans, this study aimed at distinguishing plan characteristics of the two planning formats and examining their role as predictors of later plan enactment.

METHODS

Secondary analyses of a three-arm RCT with German couples (data collection between 2013 and 2015). Couples were assigned to an individual (IPC, n = 114) or dyadic planning condition (DPC, n = 111) and formulated up to 5 physical activity plans for a target person. Couples assigned to a control condition were not included as they did not generate plans. The following characteristics were distinguished and coded for each plan: number of planned opportunities, presence of a planned routine, planned cue- or activity-related specificity, activity-related intensity, and chronological plan rank. One week before (T0) and two weeks following (T2) the intervention (T1), increase vs. no increase of the planned activity was coded as a dichotomous plan enactment variable. Multilevel logistic regressions were fit.

RESULTS

Plan enactment was higher in dyadic than in individual planners. Findings indicated that routines (e.g., after work) were positively related to plan enactment, whereas a high specificity of when-cues (e.g., Friday at 6.30 p.m.) showed a negative relationship. None of the examined plan characteristics could explain differences in enactment between IPC and DPC.

CONCLUSIONS

Linking health behaviours to other behavioural routines seems beneficial for subsequent plan enactment. Dyadic planning was linked with higher enactment rates than individual planning. However, as mechanisms underlying this effect remain unclear, they should be investigated further.

Goal Disengagement, Well-Being, and Goal Achievement in Romantic Couples Pursuing Health Behavior Change: Evidence from Two Daily Diary Studies

BACKGROUND

Withdrawing effort and commitment from important goals (i.e. goal disengagement) has been discussed as an effective aspect of goal adaption. However, studies have focused especially on between-person differences. The present studies aimed to investigate within-person differences in goal disengagement within a dyadic context of romantic couples. Across two different health behaviors, we specifically tested whether goal disengagement would be associated with better well-being, but lower goal achievement in everyday life.

METHODS

In two dyadic daily diary studies (Study 1: 61 overweight couples aiming to become physically active; Study 2: 83 dual-smoker couples aiming to quit smoking), both partners independently reported on goal disengagement, positive and negative affect. Behavioral goal achievement was measured via accelerometer (Study 1) and self-report (Study 2).

RESULTS

Analyses based on the Actor-Partner Interdependence Model revealed that across both studies, one's own goal disengagement was related to lower well-being and a lower likelihood for goal achievement on a daily level (actor effects). Only in Study 1 were partner effects on negative affect and goal achievement found.

CONCLUSIONS

In daily life, goal disengagement may not be as adaptive for well-being and goal achievement in health behavior change. Dyadic associations were not consistent, and might be more context-sensitive.

Assessing adherence to multiple medications and in daily life among patients with multimorbidity

OBJECTIVE

Chronic conditions often require multiple medication intake. However, past research has focused on assessing overall adherence or adherence to a single index medication only. This study explored adherence measures for multiple medication intake, and in daily life, among patients with multiple chronic conditions (i.e. multimorbidity).

DESIGN

Eighty-four patients with multimorbidity and multiple-medication regimens completed three monthly panel questionnaires. A randomly assigned subsample additionally completed a 30-day daily diary.

MAIN OUTCOME MEASURE

The Non-Adherence Report; a brief self-report measure of adherence to each prescribed medication (NAR-M), and in daily life. We further assessed the Medication Adherence Report Scale (MARS), and a subsample of participants were randomised to electronic adherence monitoring.

RESULTS

The NAR-M indicated M = 94.7% adherence at Time 1 (SD = 9.3%). The NAR-M was significantly correlated with the MARS (r_t1 = .52, r_t2 = .57, and r_t3 = .65; p < .001), and in tendency with electronically assessed adherence (r_t2 = .45, r_t3 = .46, p < .10). Variance components analysis indicated that between-person differences accounted for 10.2% of the variance in NAR-M adherence rates, whereas 22.9% were attributable to medication by person interactions.

CONCLUSION

This study highlights the importance and feasibility of studying adherence to multiple medications differentially, and in daily life. Future studies may use these measures to investigate within-person and between-medication differences in adherence.