The frequency of using wearable activity trackers is associated with minutes of moderate to vigorous physical activity among cancer survivors: Analysis of HINTS data.

BACKGROUND: Despite the health benefits, cancer survivors tend to exercise less after diagnosis and treatment. Wearable activity trackers (WATs) can provide avenues for self-monitoring and may enhance exercise motivation and enjoyment. However, less is known about the relationship between how often survivors use wearables and their amount of moderate to vigorous physical activity (MVPA). METHODS: Data was utilized from the National Cancer Institute's Health Information National Trend Survey 5 Cycles 3-4 (January 2019 - June 2020). To account for overdispersion and excessive zeros in the outcome variable (weekly minutes of MVPA), a zero inflated negative binomial regression model was used. RESULTS: The majority of the sample (n = 1369) were female (n = 735, 53.7 %), non-Hispanic White (n = 961, 70.2 %) and 34.3 % (n = 664) were between the ages of 65-74 years. Non-melanoma skin cancer was the most frequently reported cancer type (n = 334, 24.4 %) and 48.5 % (n = 664) reported that it had been 11 + years since their diagnosis. Survivors who reported daily WAT use were estimated to have 3.53 times higher number of MVPA minutes per week compared to survivors who reported non-daily WAT usage (RR: 3.53, 2.76-4.53, p = <0.001). Based on the model, daily WAT users had an expected mean MVPA of 202 min per week (95 % CI: 191.15-226.59) compared to non-daily users (132 min, 95 % CI: 119.81-140.22) and non-WAT users (88 min, 95 % CI: 84.46-92.50). CONCLUSION: According to this model, survivors who reported daily WAT use were estimated on average to have weekly MVPA minutes that meet or exceed MVPA recommendations (>= 150 min of MVPA per week) compared to survivors who reported infrequent or no WAT use. Wearables may provide an opportunity for survivors to engage in self-monitoring and can potentially support exercise tracking and engagement.

Optimization of a Transdiagnostic Mobile Emotion Regulation Intervention for University Students: Protocol for a Microrandomized Trial.

BACKGROUND: Many university students experience mental health problems such as anxiety and depression. To support their mental health, a transdiagnostic mobile app intervention has been developed. The intervention provides short exercises rooted in various approaches (eg, positive psychology, mindfulness, self-compassion, and acceptance and commitment therapy) that aim to facilitate adaptive emotion regulation (ER) to help students cope with the various stressors they encounter during their time at university. OBJECTIVE: The goals of this study are to investigate whether the intervention and its components function as intended and how participants engage with them. In addition, this study aims to monitor changes in distress symptoms and ER skills and identify relevant contextual factors that may moderate the intervention's impact. METHODS: A sequential explanatory mixed methods design combining a microrandomized trial and semistructured interviews will be used. During the microrandomized trial, students (N=200) will be prompted via the mobile app twice a day for 3 weeks to evaluate their emotional states and complete a randomly assigned intervention (ie, an exercise supporting ER) or a control intervention (ie, a health information snippet). A subsample of participants (21/200, 10.5%) will participate in interviews exploring their user experience with the app and the completed exercises. The primary outcomes will be changes in emotional states and engagement with the intervention (ie, objective and subjective engagement). Objective engagement will be evaluated through log data (eg, exercise completion time). Subjective engagement will be evaluated through exercise likability and helpfulness ratings as well as user experience interviews. The secondary outcomes will include the distal outcomes of the intervention (ie, ER skills and distress symptoms). Finally, the contextual moderators of intervention effectiveness will be explored (eg, the time of day and momentary emotional states). RESULTS: The study commenced on February 9, 2023, and the data collection was concluded on June 13, 2023. Of the 172 eligible participants, 161 (93.6%) decided to participate. Of these 161 participants, 137 (85.1%) completed the first phase of the study. A subsample of participants (18/172, 10.5%) participated in the user experience interviews. Currently, the data processing and analyses are being conducted. CONCLUSIONS: This study will provide insight into the functioning of the intervention and identify areas for improvement. Furthermore, the findings will shed light on potential changes in the distal outcomes of the intervention (ie, ER skills and distress symptoms), which will be considered when designing a follow-up randomized controlled trial evaluating the full-scale effectiveness of this intervention. Finally, the results and data gathered will be used to design and train a recommendation algorithm that will be integrated into the app linking students to relevant content. TRIAL REGISTRATION: ClinicalTrials.gov NCT05576883; https://www.clinicaltrials.gov/study/NCT05576883. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/46603.

Validity and Reliability of the Occupational Balance Questionnaire (OBQ11) in a U.S. Sample of Adults With Type 1 Diabetes.

IMPORTANCE: Although occupational balance (OB) is a construct of importance to occupational therapy, existing OB assessments have not been validated in clinical populations. OBJECTIVE: To examine the validity and reliability of the 11-item version of the Occupational Balance Questionnaire (OBQ11) in U.S. adults with Type 1 diabetes. DESIGN: Data were analyzed from adults with Type 1 diabetes enrolled in a larger longitudinal study examining the relationships among blood glucose, emotion, and functioning. Dimensionality of the OBQ11 was assessed with item response theory (IRT); convergent validity was tested by examining whether associations between the OBQ11 and other constructs were consistent with a priori hypotheses. SETTING: Three outpatient clinical sites in the United States. PARTICIPANTS: Data from 208 U.S. adults with Type 1 diabetes were included in the analyses (42% Latino, 29% White, 14% African American, 7% multiethnic, and 8% other). OUTCOMES AND MEASURES: Assessments administered include the OBQ11, Patient Health Questionnaire (depression), and Diabetes Self-Management Questionnaire. RESULTS: Overall, results from IRT models and correlational tests supported the reliability and validity of the OBQ11. For instance, higher scores on the OBQ11 were significantly associated with better self-ratings of diabetes management behaviors (r = .28, p < .001), lower depression symptoms (r = -.53, p < .001), and greater positive affect (r = .32, p < .001). A single-factor generalized partial credit model fit the OBQ11 acceptably well, supporting its unidimensionality. CONCLUSIONS AND RELEVANCE: The OBQ11 may be a reliable and valid measure of OB appropriate for use in clinical populations such as adults with diabetes. What This Article Adds: OB is not often formally assessed by occupational therapists in the United States, even though the contributions of OB to health and well-being are core components of the philosophy of occupational therapy. The current evidence supports the validity of the OBQ11 in a clinical population of adults with Type 1 diabetes and demonstrates significant associations between OB and health management behaviors. Study results may encourage greater consideration and assessment of OB in occupational therapy clinical practice in the United States.

Within-person relationships of sleep duration with next-day stress and affect in the daily life of adults with Type-1 diabetes.

OBJECTIVE: The objective of this study is to examine the within-person relationships between sleep duration and next-day stress and affect in the daily life of individuals with T1D. METHODS: Study participants were recruited in the Function and Emotion in Everyday Life with Type 1 Diabetes (FEEL-T1D) study. Sleep duration was derived by synthesizing objective (actigraphy) and self-report measures. General and diabetes-specific stress and positive and negative affect were measured using ecological momentary assessment. Multilevel regression was used to examine the within-person relationships between sleep duration and next-day stress and affect. Cross-level interactions were used to explore whether gender and baseline depression and anxiety moderated these within-person relationships. RESULTS: Adults with T1D (n = 166) completed measurements for 14 days. The average age was 41.0 years, and 91 participants (54.8%) were female. The average sleep duration was 7.3 h (SD = 1.2 h). Longer sleep was significantly associated with lower general stress (p < 0.001) but not diabetes-specific stress (p = 0.18) on the next day. There were significant within-person associations of longer sleep with lower levels on next-day negative affect (overall, p = 0.002, disappoint, p = 0.05; sad, p = 0.05; tense, p < 0.001; upset, p = 0.008; anxious, p = 0.04). There were no significant associations with positive affect. Examination of the interaction effects did not reveal significant differential relationships for men and women and for individuals with and without depression or anxiety at baseline. CONCLUSION: Findings from this study suggest optimizing sleep duration as an important interventional target for better managing general stress and improving daily emotional wellbeing of individuals with T1D.

Reliability and Validity of Noncognitive Ecological Momentary Assessment Survey Response Times as an Indicator of Cognitive Processing Speed in People's Natural Environment: Intensive Longitudinal Study.

BACKGROUND: Various populations with chronic conditions are at risk for decreased cognitive performance, making assessment of their cognition important. Formal mobile cognitive assessments measure cognitive performance with greater ecological validity than traditional laboratory-based testing but add to participant task demands. Given that responding to a survey is considered a cognitively demanding task itself, information that is passively collected as a by-product of ecological momentary assessment (EMA) may be a means through which people's cognitive performance in their natural environment can be estimated when formal ambulatory cognitive assessment is not feasible. We specifically examined whether the item response times (RTs) to EMA questions (eg, mood) can serve as approximations of cognitive processing speed. OBJECTIVE: This study aims to investigate whether the RTs from noncognitive EMA surveys can serve as approximate indicators of between-person (BP) differences and momentary within-person (WP) variability in cognitive processing speed. METHODS: Data from a 2-week EMA study investigating the relationships among glucose, emotion, and functioning in adults with type 1 diabetes were analyzed. Validated mobile cognitive tests assessing processing speed (Symbol Search task) and sustained attention (Go-No Go task) were administered together with noncognitive EMA surveys 5 to 6 times per day via smartphones. Multilevel modeling was used to examine the reliability of EMA RTs, their convergent validity with the Symbol Search task, and their divergent validity with the Go-No Go task. Other tests of the validity of EMA RTs included the examination of their associations with age, depression, fatigue, and the time of day. RESULTS: Overall, in BP analyses, evidence was found supporting the reliability and convergent validity of EMA question RTs from even a single repeatedly administered EMA item as a measure of average processing speed. BP correlations between the Symbol Search task and EMA RTs ranged from 0.43 to 0.58 (P<.001). EMA RTs had significant BP associations with age (P<.001), as expected, but not with depression (P=.20) or average fatigue (P=.18). In WP analyses, the RTs to 16 slider items and all 22 EMA items (including the 16 slider items) had acceptable (>0.70) WP reliability. After correcting for unreliability in multilevel models, EMA RTs from most combinations of items showed moderate WP correlations with the Symbol Search task (ranged from 0.29 to 0.58; P<.001) and demonstrated theoretically expected relationships with momentary fatigue and the time of day. The associations between EMA RTs and the Symbol Search task were greater than those between EMA RTs and the Go-No Go task at both the BP and WP levels, providing evidence of divergent validity. CONCLUSIONS: Assessing the RTs to EMA items (eg, mood) may be a method of approximating people's average levels of and momentary fluctuations in processing speed without adding tasks beyond the survey questions.

Impact of Overnight Glucose on Next-Day Functioning in Adults With Type 1 Diabetes: An Exploratory Intensive Longitudinal Study.

OBJECTIVE: While there is evidence that functioning, or ability to perform daily life activities, can be adversely influenced by type 1 diabetes, the impact of acute fluctuations in glucose levels on functioning is poorly understood. RESEARCH DESIGN AND METHODS: Using dynamic structural equation modeling, we examined whether overnight glucose (coefficient of variation[CV], percent time <70 mg/dL, percent time >250 mg/dL) predicted seven next-day functioning outcomes (mobile cognitive tasks, accelerometry-derived physical activity, self-reported activity participation) in adults with type 1 diabetes. We examined mediation, moderation, and whether short-term relationships were predictive of global patient-reported outcomes. RESULTS: Overall next-day functioning was significantly predicted from overnight CV (P = 0.017) and percent time >250 mg/dL (P = 0.037). Pairwise tests indicate that higher CV is associated with poorer sustained attention (P = 0.028) and lower engagement in demanding activities (P = 0.028), time <70 mg/dL is associated with poorer sustained attention (P = 0.007), and time >250 mg/dL is associated with more sedentary time (P = 0.024). The impact of CV on sustained attention is partially mediated by sleep fragmentation. Individual differences in the effect of overnight time <70 mg/dL on sustained attention predict global illness intrusiveness (P = 0.016) and diabetes-related quality of life (P = 0.036). CONCLUSIONS: Overnight glucose predicts problems with objective and self-reported next-day functioning and can adversely impact global patient-reported outcomes. These findings across diverse outcomes highlight the wide-ranging effects of glucose fluctuations on functioning in adults with type 1 diabetes.

Glycemic Risk Index Profiles and Predictors Among Diverse Adults With Type 1 Diabetes.

BACKGROUND: The Glycemia Risk Index (GRI) was introduced as a single value derived from the ambulatory glucose profile that identifies patients who need attention. This study describes participants in each of the five GRI zones and examines the percentage of variation in GRI scores that is explained by sociodemographic and clinical variables among diverse adults with type 1 diabetes. METHODS: A total of 159 participants provided blinded continuous glucose monitoring (CGM) data over 14 days (mean age [SD] = 41.4 [14.5] years; female = 54.1%, Hispanic = 41.5%). Glycemia Risk Index zones were compared on CGM, sociodemographic, and clinical variables. Shapley value analysis examined the percentage of variation in GRI scores explained by different variables. Receiver operating characteristic curves examined GRI cutoffs for those more likely to have experienced ketoacidosis or severe hypoglycemia. RESULTS: Mean glucose and variability, time in range, and percentage of time in high, and very high, glucose ranges differed across the five GRI zones (P values < .001). Multiple sociodemographic indices also differed across zones, including education level, race/ethnicity, age, and insurance status. Sociodemographic and clinical variables collectively explained 62.2% of variance in GRI scores. A GRI score ≥84.5 reflected greater likelihood of ketoacidosis (area under the curve [AUC] = 0.848), and scores ≥58.2 reflected greater likelihood of severe hypoglycemia (AUC = 0.729) over the previous six months. CONCLUSIONS: Results support the use of the GRI, with GRI zones identifying those in need of clinical attention. Findings highlight the need to address health inequities. Treatment differences associated with the GRI also suggest behavioral and clinical interventions including starting individuals on CGM or automated insulin delivery systems.

Movement matters: short-term impacts of physical activity on mood and well-being.

Few studies have investigated the short-term, momentary relationships between physical activity (PA) and well-being. This study focuses on investigating the dynamic relationships between PA and affective well-being among adults with type 1 diabetes. Participants (n = 122) wore an accelerometer and completed daily EMA surveys of current activities and affective states (e.g., happy, stressed, excited, anxious) via smartphone over 14 days. Within-person, increased sedentary time was associated with less positive affect (r = - 0.11, p < 0.001), while more PA of any intensity was associated with greater positive affect and reduced fatigue, three hours later. Between-person, increased light PA was associated with increased stress (r = 0.21, p = 0.02) and diabetes distress (r = 0.30, p = 0.001). This study provides evidence that positive affect and fatigue are predicted by previous activity regardless of the different activities that people engaged in. Positive affect increased after engaging in PA. However, participants with higher amounts of light PA reported higher stress ratings.

Within-person Relationships of Sleep Duration with Next-Day Stress and Affect in the Daily Life of Adults with Type-1 Diabetes.

Objective: The objective of this study is to examine the within-person relationships between sleep duration and next-day stress and affect in the daily life of individuals with T1D. Methods: Study participants were recruited in the Function and Emotion in Everyday Life with Type 1 Diabetes (FEEL-T1D) study. Sleep duration was derived by synthesizing objective (actigraphy) and self-report measures. General and diabetes-specific stress and positive and negative affect were measured using ecological momentary assessment. Multilevel regression was used to examine the within-person relationships between sleep duration and next-day stress and affect. Cross-level interactions were used to explore whether gender and baseline depression and anxiety moderated these within-person relationships. Results: Adults with T1D (n=166) completed measurements for 14 days. The average age was 40.99 years, and 91 participants (54.82%) were female. The average sleep duration was 7.29 hours (SD=1.18 hours). Longer sleep was significantly associated with lower general stress (p<0.001) but not diabetes-specific stress (p=0.18) on the next day. There were significant within-person associations of longer sleep with lower levels on next-day negative affect (overall, p=0.002, disappoint, p=0.05; sad, p=0.05; tense, p<0.001; upset, p=0.008; anxious, p=0.04). There were no significant associations with positive affect. Examination of the interaction effects did not reveal significant differential relationships for men and women and for individuals with and without depression or anxiety at baseline. Conclusion: Findings from this study suggest optimizing sleep duration as an important interventional target for better managing general stress and improving daily emotional wellbeing of individuals with T1D.

The ILHBN: challenges, opportunities, and solutions from harmonizing data under heterogeneous study designs, target populations, and measurement protocols.

The ILHBN is funded by the National Institutes of Health to collaboratively study the interactive dynamics of behavior, health, and the environment using Intensive Longitudinal Data (ILD) to (a) understand and intervene on behavior and health and (b) develop new analytic methods to innovate behavioral theories and interventions. The heterogenous study designs, populations, and measurement protocols adopted by the seven studies within the ILHBN created practical challenges, but also unprecedented opportunities to capitalize on data harmonization to provide comparable views of data from different studies, enhance the quality and utility of expensive and hard-won ILD, and amplify scientific yield. The purpose of this article is to provide a brief report of the challenges, opportunities, and solutions from some of the ILHBN's cross-study data harmonization efforts. We review the process through which harmonization challenges and opportunities motivated the development of tools and collection of metadata within the ILHBN. A variety of strategies have been adopted within the ILHBN to facilitate harmonization of ecological momentary assessment, location, accelerometer, and participant engagement data while preserving theory-driven heterogeneity and data privacy considerations. Several tools have been developed by the ILHBN to resolve challenges in integrating ILD across multiple data streams and time scales both within and across studies. Harmonization of distinct longitudinal measures, measurement tools, and sampling rates across studies is challenging, but also opens up new opportunities to address cross-cutting scientific themes of interest.

Health behavior changes, such as prevention of suicidal thoughts and behaviors, smoking, drug use, and alcohol use; and the promotion of mental health, sleep, and physical activities, and decreases in sedentary behavior, are difficult to sustain. The ILHBN is a cooperative agreement network funded jointly by seven participating units within the National Institutes of Health to collaboratively study how factors that occur in individuals' everyday life and in their natural environment influence the success of positive health behavior changes. This article discusses how information collected using smartphones, wearables, and other devices can provide helpful active and passive reflections of the participants' extent of risk and resources at the moment for an extended period of time. However, successful engagement and retention of participants also require tailored adaptations of study designs, measurement tools, measurement intervals, study span, and device choices that create hurdles in integrating (harmonizing) data from multiple studies. We describe some of the challenges, opportunities, and solutions that emerged from harmonizing intensive longitudinal data under heterogeneous study and participant characteristics within the ILHBN, and share some tools and recommendations to facilitate future data harmonization efforts.

Advancing Behavioral Intervention and Theory Development for Mobile Health: The HeartSteps II Protocol.

Background: Recent advances in mobile and wearable technologies have led to new forms of interventions, called "Just-in-Time Adaptive Interventions" (JITAI). JITAIs interact with the individual at the most appropriate time and provide the most appropriate support depending on the continuously acquired Intensive Longitudinal Data (ILD) on participant physiology, behavior, and contexts. These advances raise an important question: How do we model these data to better understand and intervene on health behaviors? The HeartSteps II study, described here, is a Micro-Randomized Trial (MRT) intended to advance both intervention development and theory-building enabled by the new generation of mobile and wearable technology. Methods: The study involves a year-long deployment of HeartSteps, a JITAI for physical activity and sedentary behavior, with 96 sedentary, overweight, but otherwise healthy adults. The central purpose is twofold: (1) to support the development of modeling approaches for operationalizing dynamic, mathematically rigorous theories of health behavior; and (2) to serve as a testbed for the development of learning algorithms that JITAIs can use to individualize intervention provision in real time at multiple timescales. Discussion and Conclusions: We outline an innovative modeling paradigm to model and use ILD in real- or near-time to individually tailor JITIAs.

Validity and Feasibility of the Monitoring and Modeling Family Eating Dynamics System to Automatically Detect In-field Family Eating Behavior: Observational Study.

BACKGROUND: The field of dietary assessment has a long history, marked by both controversies and advances. Emerging technologies may be a potential solution to address the limitations of self-report dietary assessment methods. The Monitoring and Modeling Family Eating Dynamics (M2FED) study uses wrist-worn smartwatches to automatically detect real-time eating activity in the field. The ecological momentary assessment (EMA) methodology was also used to confirm whether eating occurred (ie, ground truth) and to measure other contextual information, including positive and negative affect, hunger, satiety, mindful eating, and social context. OBJECTIVE: This study aims to report on participant compliance (feasibility) to the 2 distinct EMA protocols of the M2FED study (hourly time-triggered and eating event-triggered assessments) and on the performance (validity) of the smartwatch algorithm in automatically detecting eating events in a family-based study. METHODS: In all, 20 families (58 participants) participated in the 2-week, observational, M2FED study. All participants wore a smartwatch on their dominant hand and responded to time-triggered and eating event-triggered mobile questionnaires via EMA while at home. Compliance to EMA was calculated overall, for hourly time-triggered mobile questionnaires, and for eating event-triggered mobile questionnaires. The predictors of compliance were determined using a logistic regression model. The number of true and false positive eating events was calculated, as well as the precision of the smartwatch algorithm. The Mann-Whitney U test, Kruskal-Wallis test, and Spearman rank correlation were used to determine whether there were differences in the detection of eating events by participant age, gender, family role, and height. RESULTS: The overall compliance rate across the 20 deployments was 89.26% (3723/4171) for all EMAs, 89.7% (3328/3710) for time-triggered EMAs, and 85.7% (395/461) for eating event-triggered EMAs. Time of day (afternoon odds ratio [OR] 0.60, 95% CI 0.42-0.85; evening OR 0.53, 95% CI 0.38-0.74) and whether other family members had also answered an EMA (OR 2.07, 95% CI 1.66-2.58) were significant predictors of compliance to time-triggered EMAs. Weekend status (OR 2.40, 95% CI 1.25-4.91) and deployment day (OR 0.92, 95% CI 0.86-0.97) were significant predictors of compliance to eating event-triggered EMAs. Participants confirmed that 76.5% (302/395) of the detected events were true eating events (ie, true positives), and the precision was 0.77. The proportion of correctly detected eating events did not significantly differ by participant age, gender, family role, or height (P>.05). CONCLUSIONS: This study demonstrates that EMA is a feasible tool to collect ground-truth eating activity and thus evaluate the performance of wearable sensors in the field. The combination of a wrist-worn smartwatch to automatically detect eating and a mobile device to capture ground-truth eating activity offers key advantages for the user and makes mobile health technologies more accessible to nonengineering behavioral researchers.

Effects of Group-delivered Stress-reduction Guided Imagery on Salivary Cortisol, Salivary Amylase, and Stress Mood in Urban, Predominantly Latino Adolescents.

OBJECTIVES: To determine acute effects of stress-reduction guided imagery delivered in group format on stress biomarkers salivary cortisol and salivary amylase, and on self-reported stress mood, in healthy, predominantly Latino adolescents. STUDY DESIGN: 111 adolescent participants (94% Latino), a subset from a large, randomized controlled lifestyle intervention to improve obesity-related health behaviors, received either 4 weekly lifestyle education sessions (Lifestyle group; LS) or the same weekly lifestyle education sessions plus an additional weekly stress-reduction guided imagery session delivered in group format (Guided imagery group; GI). Salivary cortisol, salivary amylase, and self-reported stress moods were assessed before and after sessions on intervention weeks 3 and 4. Statistics: Linear mixed effects models examined within- and between-session and group differences in pre- to post-session changes. RESULTS: Both groups showed decreases in salivary cortisol, 5% decrease in LS group and 32% in GI group (within-group differences all P < .05), with between-group difference in salivary cortisol of moderate size (P = .05; Cohen's d = .44). Within the GI group alone, salivary cortisol decrease was similar following either the lifestyle or GI sessions (P = .64). There were no statistically significant amylase changes within or between groups. All 5 individual stress moods declined by 27% to 46% in the GI group (all P < .05), while only 1 of the 5 declined in LS group. CONCLUSIONS: Group stress-reduction guided imagery reduces the stress biomarker salivary cortisol, as well as reducing subjective stress mood states, making it a viable modality for large scale stress-reduction interventions.

Perspective: A Framework for Addressing Dynamic Food Consumption Processes.

The study of food consumption, diet, and related concepts is motivated by diverse goals, including understanding why food consumption impacts our health, and why we eat the foods we do. These varied motivations can make it challenging to define and measure consumption, as it can be specified across nearly infinite dimensions-from micronutrients to carbon footprint to food preparation. This challenge is amplified by the dynamic nature of food consumption processes, with the underlying phenomena of interest often based on the nature of repeated interactions with food occurring over time. This complexity underscores a need to not only improve how we measure food consumption but is also a call to support theoreticians in better specifying what, how, and why food consumption occurs as part of processes, as a prerequisite step to rigorous measurement. The purpose of this Perspective article is to offer a framework, the consumption process framework, as a tool that researchers in a theoretician role can use to support these more robust definitions of consumption processes. In doing so, the framework invites theoreticians to be a bridge between practitioners who wish to measure various aspects of food consumption and methodologists who can develop measurement protocols and technologies that can support measurement when consumption processes are clearly defined. In the paper we justify the need for such a framework, introduce the consumption process framework, illustrate the framework via a use case, and discuss existing technologies that enable the use of this framework and, by extension, more rigorous study of consumption. This consumption process framework demonstrates how theoreticians could fundamentally shift how food consumption is defined and measured towards more rigorous study of what, how, and why food is eaten as part of dynamic processes and a deeper understanding of linkages between behavior, food, and health.

Survivors' health competence mediates the association between wearable activity tracker use and self-rated health: HINTS analysis.

PURPOSE: Physical activity (PA) plays an important role in achieving positive self-rated health (SRH) among cancer survivors. Wearable activity trackers (WATs) can be effective for self-monitoring and tracking PA. Studies have shown that survivors who use WATs are more likely to engage in more PA. However, few studies have examined the direct and indirect associations between WAT use, PA, and SRH mediated by constructs derived from self-determination theory, perceived health competence, and perceived social relatedness for health. METHODS: Data on survivors were analyzed from National Cancer Institute's Health Information National Trend Survey (HINTS) Cycle 1-3 (n = 1,421). Path analysis was used to test the total, direct, and indirect associations. RESULTS: Previous WAT use was directly associated with PA level (standardized beta (SB): 0.07, p = 0.005) and indirectly associated with SRH (SB: 0.04, p = 0.005), mediated by perceived health competence and PA. Perceived health competence was directly associated with SRH (SB: 0.51, p < .0001) and PA (SB: 0.20, p < .0001), and perceived social relatedness for health was not significantly associated with PA (SB: 0.005, p = 0.8) or SRH (SB: 0.02, p = 0.31). CONCLUSIONS: Overall, these results indicate that perceived health competence significantly mediated the associations between WAT use and SRH; however, WAT use was only directly associated with PA and was not mediated. IMPLICATIONS FOR CANCER SURVIVORS: These findings support the notion that WATs may play a role in addressing SRH among cancer survivors through fostering perceived health competence by providing real-time feedback, goal setting, and opportunities for self-monitoring.

BayesLDM: A Domain-specific Modeling Language for Probabilistic Modeling of Longitudinal Data.

In this paper we present BayesLDM, a library for Bayesian longitudinal data modeling consisting of a high-level modeling language with specific features for modeling complex multivariate time series data coupled with a compiler that can produce optimized probabilistic program code for performing inference in the specified model. BayesLDM supports modeling of Bayesian network models with a specific focus on the efficient, declarative specification of dynamic Bayesian Networks (DBNs). The BayesLDM compiler combines a model specification with inspection of available data and outputs code for performing Bayesian inference for unknown model parameters while simultaneously handling missing data. These capabilities have the potential to significantly accelerate iterative modeling workflows in domains that involve the analysis of complex longitudinal data by abstracting away the process of producing computationally efficient probabilistic inference code. We describe the BayesLDM system components, evaluate the efficiency of representation and inference optimizations and provide an illustrative example of the application of the system to analyzing heterogeneous and partially observed mobile health data.

The Acute Relationship between Affective States and Stress Biomarkers in Ethnic Minority Youths.

Background: Whether affective states acutely predict the hypothalamic-pituitary-adrenal (HPA) axis activities and whether energy balance-related behaviors moderate the affect-HPA axis relationship in obese youths are not well-understood. Methods: 87 mostly obese (94.3% obese) minority adolescents (mean: 16.3 ± 1.2 years old; 56.8% Latino and 43.2% African American) participated in a randomized crossover trial in an observation laboratory, where they received either high-sugar/low-fiber (HSLF) or low-sugar/high-fiber (LSHF) meals first and then crossed over in the next visit 2-4 weeks later. During each visit, they rated five affective states and provided a saliva sample every 30 min for the first 5 h and wore a waist-worn accelerometer. The association between the affect ratings and cortisol levels in the subsequent 30 min and the moderation effect of energy balance-related behavior were examined using multilevel models. Results: Within-person negative affect (ß = 0.02, p = 0.0343) and feeling of panic (ß = 0.007, p = 0.004) were acutely related to the subsequent cortisol level only during the HSLF condition. The time spent in moderate-to-vigorous physical activity did not moderate the acute relationship between affect and the subsequent cortisol level. Conclusions: Negative affect could be acutely related to heightened HPA axis activities in youths, but only when they were exposed to meals with high sugar and low fiber content. These results suggest that the meals' sugar and fiber content may modulate HPA axis reactivity to negative affect in youths.

Understanding Worker Well-Being Relative to High-Workload and Recovery Activities across a Whole Day: Pilot Testing an Ecological Momentary Assessment Technique.

Occupational health and safety is experiencing a paradigm shift from focusing only on health at the workplace toward a holistic approach and worker well-being framework that considers both work and non-work factors. Aligned with this shift, the purpose of this pilot study was to examine how, within a person, frequencies of high-workload and recovery activities from both work and non-work periods were associated with same day well-being measures. We analyzed data on 45 workers with type 1 diabetes from whom we collected activity data 5-6 times daily over 14 days. More frequent engagement in high-workload activities was associated with lower well-being on multiple measures including higher stress. Conversely, greater recovery activity frequency was mostly associated with higher well-being indicated by lower stress and higher positive affect. Overall, our results provide preliminary validity evidence for measures of high-workload and recovery activity exposure covering both work and non-work periods that can inform and support evaluations of worker well-being.

Function and Emotion in Everyday Life With Type 1 Diabetes (FEEL-T1D): Protocol for a Fully Remote Intensive Longitudinal Study.

BACKGROUND: Although short-term blood glucose levels and variability are thought to underlie diminished function and emotional well-being in people with type 1 diabetes (T1D), these relationships are poorly understood. The Function and Emotion in Everyday Life with T1D (FEEL-T1D) study focuses on investigating these short-term dynamic relationships among blood glucose levels, functional ability, and emotional well-being in adults with T1D. OBJECTIVE: The aim of this study is to present the FEEL-T1D study design, methods, and study progress to date, including adaptations necessitated by the COVID-19 pandemic to implement the study fully remotely. METHODS: The FEEL-T1D study will recruit 200 adults with T1D in the age range of 18-75 years. Data collection includes a comprehensive survey battery, along with 14 days of intensive longitudinal data using blinded continuous glucose monitoring, ecological momentary assessments, ambulatory cognitive tasks, and accelerometers. All study procedures are conducted remotely by mailing the study equipment and by using videoconferencing for study visits. RESULTS: The study received institutional review board approval in January 2019 and was funded in April 2019. Data collection began in June 2020 and is projected to end in December 2021. As of June 2021, after 12 months of recruitment, 124 participants have enrolled in the FEEL-T1D study. Approximately 87.6% (7082/8087) of ecological momentary assessment surveys have been completed with minimal missing data, and 82.0% (82/100) of the participants provided concurrent continuous glucose monitoring data, ecological momentary assessment data, and accelerometer data for at least 10 of the 14 days of data collection. CONCLUSIONS: Thus far, our reconfiguration of the FEEL-T1D protocol to be implemented remotely during the COVID-19 pandemic has been a success. The FEEL-T1D study will elucidate the dynamic relationships among blood glucose levels, emotional well-being, cognitive function, and participation in daily activities. In doing so, it will pave the way for innovative just-in-time interventions and produce actionable insights to facilitate tailoring of diabetes treatments to optimize the function and well-being of individuals with T1D. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/30901.

The mediating role of emotional eating in the relationship between perceived stress and dietary intake quality in Hispanic/Latino adolescents.

Obesity rates have steadily increased over the past three decades, and large racial/ethnic disparities in childhood obesity rates-specifically for Hispanic/Latino youth-highlight the major need for identifying and examining key mechanisms of obesogenic behaviors for this at-risk population. This study investigates the relationship between stress and dietary quality in Hispanic/Latino adolescents and seeks to determine the mediating role of emotional eating as a behavioral mechanism. Baseline data from 169 adolescents enrolled in the Imagine HEALTH trial were used to investigate these relationships. Perceived stress and emotional eating were assessed with age-validated questionnaires, and dietary quality was measured via 24-hour recall dietary assessments (later calculated as individual Healthy Eating Index-2015 scores). Nonparametric bootstrapping was used to test the primary hypothesis that emotional eating partially or fully mediates the relationship between perceived stress and dietary quality in this sample, and to test the significance of the mediating effect. Results indicate that emotional eating partially mediates the relationship between perceived stress and dietary quality. The total effect of perceived stress scores on dietary quality scores was -0.24 (p = .006); the direct effect of perceived stress scores on dietary quality scores (controlling for emotional eating scores) was -0.16 (p = .107), and the mediating (indirect) effect of emotional eating was -0.09 (p = .001). The proportion of mediation was 0.36 (36%) (p = .008). This study identifies an important mechanism of obesogenic behavior and can be used to inform future obesity prevention and intervention strategies tailored for the Hispanic/Latino adolescent population.