This study aimed to adapt and validate the Reward-Based Eating Drive Scale (RED-13) for Brazilian Portuguese and assess its psychometric properties and predictive validity. The adaptation process followed established cross-cultural guidelines, including translation, synthesis, back-translation, expert committee review, and pilot testing. Content validity was evaluated using the Content Validity Index. A total of 452 adults aged 18-59 years, recruited online, participated in the psychometric assessment. Confirmatory factor analysis supported the scale's three-dimensional structure (RMSEA < 0.0001, SRMR = 0.041, TLI = 1.000, CFI = 1.000). Internal consistency was high (α = 0.921, ω = 0.922). RED-13 BR scores showed moderate correlations with food cravings and weak correlations with body mass index (rho = 0.266, p < 0.001). Receiver operating characteristic analysis indicated predictive ability for pre-obesity and obesity. These findings suggest that the RED-13 BR is a valid and reliable instrument for assessing reward-based eating behavior in Brazilian adults.

BackgroundThe recent emergence of wearable devices has made feasible the passive gathering of intensive, longitudinal data from large groups of individuals. This form of data is effective at capturing physiological changes between participants (interindividual variability) and changes within participants over time (intraindividual variability). The emergence of longitudinal datasets provides an opportunity to quantify the contribution of such longitudinal data to the control of these sources of variability for applications such as responder analysis, where traditional, sparser sampling methods may hinder the categorization of individuals into these phenotypes. ObjectiveThis study aimed to quantify the gains made in statistical power and effect size among statistical comparisons when controlling for interindividual variability and intraindividual variability compared with controlling for neither. MethodsHere, we test the gains in statistical power from controlling for interindividual and intraindividual variability of resting heart rate, collected in 2020 for over 40,000 individuals as part of the TemPredict study on COVID-19 detection. We compared heart rate on weekends with that on weekdays because weekends predictably change the behavior of most individuals, though not all, and in different ways. Weekends also repeat consistently, making their effects on heart rate feasible to assess with confidence over large populations. We therefore used weekends as a model system to test the impact of different statistical controls on detecting a recurring event with a clear ground truth. We randomly and iteratively sampled heart rate from weekday and weekend nights, controlling for interindividual variability, intraindividual variability, both, or neither. ResultsBetween-participant variability appeared to be a greater source of structured variability than within-participant fluctuations. Accounting for interindividual variability through within-individual sampling required 40× fewer pairs of samples to achieve statistical significance with 4× to 5× greater effect size at significance. Within-individual sampling revealed differential effects of weekends on heart rate, which were obscured by aggregated sampling methods. ConclusionsThis work highlights the leverage provided by longitudinal, within-individual sampling to increase statistical power among populations with heterogeneous effects.

Objective: Eating in response to stress can become habitual and have long-term consequences for weight gain, but little research has explored what may help break stress-eating cycles. We examined daily social resources as potential protective factors against daily stress eating and eventual weight gain. Method: In Study 1 (N = 1,264), we assessed stress-eating tendencies, body mass index (BMI) and waist-to-hip ratio (WHR) at baseline, receipt of emotional support over 8 days (9,649 reports), and tracked BMI/WHR after about 10 years. We examined the average likelihood of receiving emotional support as a moderator of the link between stress eating and BMI/WHR at the follow-up. In Study 2 (N = 536; 10,288 reports), we assessed stress-eating status and BMI at baseline, social responsiveness (feeling that others are caring), and stress-eating behavior over 24 days and tracked BMI a year later. We examined if social responsiveness moderates stress-eaters' daily stress-eating behaviors and changes in BMI. Results: In Study 1, stress eating predicted increases in BMI and WHR at the 10-year follow-up but not among individuals who were more (vs. less) likely to receive emotional support in daily life. In Study 2, stress eaters tended to report more daily stress-eating behaviors compared to nonstress eaters, but such tendency was attenuated on days they perceived high (vs. low) levels of social responsiveness. Stress eating did not predict BMI at the 1-year follow-up. Conclusions: These observational findings suggest that social resources in daily lives may have long-term benefits for stress eaters, potentially by reducing their everyday stress eating. Objetivo: Comer en respuesta al estr & eacute;s puede volverse habitual y tener consecuencias a largo plazo en el aumento de peso, pero poca investigaci & oacute;n ha explorado qu & eacute; puede ayudar a romper los ciclos de alimentaci & oacute;n por estr & eacute;s. Examinamos los recursos sociales diarios como posibles factores protectores contra la alimentaci & oacute;n diaria por estr & eacute;s y el eventual aumento de peso. M & eacute;todos: En el estudio 1 (N = 1,264), evaluamos las tendencias a comer por estr & eacute;s, el & iacute;ndice de masa corporal (BMI, por sus siglas en ingl & eacute;s) y la relaci & oacute;n cintura-cadera (WHR, por sus siglas en ingl & eacute;s) al inicio del estudio, la recepci & oacute;n de apoyo emocional durante ocho d & iacute;as (9,649 informes) y realizamos un seguimiento de BMI/WHR despu & eacute;s de unos diez a & ntilde;os. Examinamos la probabilidad promedio de recibir apoyo emocional como moderador del v & iacute;nculo entre comer por estr & eacute;s y el BMI/WHR en el seguimiento. En el Estudio 2 (N = 536; 10,288 informes), evaluamos el estado de alimentaci & oacute;n por estr & eacute;s y el BMI al inicio del estudio, la capacidad de respuesta social (sentir que los dem & aacute;s se preocupan) y el comportamiento de alimentaci & oacute;n por estr & eacute;s durante 24 d & iacute;as y realizamos un seguimiento del BMI un a & ntilde;o despu & eacute;s. Examinamos si la capacidad de respuesta social modera las conductas diarias de alimentaci & oacute;n estresada de los consumidores y los cambios en el BMI. Resultados: En el Estudio 1, comer por estr & eacute;s predijo aumentos en el BMI y el WHR en el seguimiento de 10 a & ntilde;os, pero no entre las personas que ten & iacute;an m & aacute;s (frente a menos) probabilidades de recibir apoyo emocional en la vida diaria. En el Estudio 2, los consumidores que com & iacute;an por estr & eacute;s tend & iacute;an a informar m & aacute;s conductas diarias de alimentaci & oacute;n estresada en comparaci & oacute;n con los que no com & iacute;an por estr & eacute;s, pero esa tendencia se atenuaba en los d & iacute;as en que percib & iacute;an niveles altos (frente a bajos) de capacidad de respuesta social. Comer bajo estr & eacute;s no predijo el BMI al a & ntilde;o de seguimiento. Conclusiones: Estos hallazgos observacionales sugieren que los recursos sociales en la vida diaria pueden tener beneficios a largo plazo para quienes comen por estr & eacute;s, potencialmente al reducir su alimentaci & oacute;n diaria por estr & eacute;s.

BackgroundA substantially lower proportion of female individuals participate in sufficient daily activity compared to male individuals despite the known health benefits of exercise. Investment in female sports and exercise medicine research may help close this gap; however, female individuals are underrepresented in this research. Hesitancy to include female participants is partly due to assumptions that biological rhythms driven by menstrual cycles and occurring on the timescale of approximately 28 days increase intraindividual biological variability and weaken statistical power. An analysis of continuous skin temperature data measured using a commercial wearable device found that temperature cycles indicative of menstrual cycles did not substantially increase variability in female individuals’ skin temperature. In this study, we explore physical activity (PA) data as a variable more related to behavior, whereas temperature is more reflective of physiological changes. ObjectiveWe aimed to determine whether intraindividual variability of PA is affected by biological sex, and if so, whether having menstrual cycles (as indicated by temperature rhythms) contributes to increased female intraindividual PA variability. We then sought to compare the effect of sex and menstrual cycles on PA variability to the effect of PA rhythms on the timescales of days and weeks and to the effect of nonrhythmic temporal structure in PA on the timescale of decades of life (age). MethodsWe used minute-level metabolic equivalent of task data collected using a wearable device across a 206-day study period for each of 596 individuals as an index of PA to assess the magnitudes of variability in PA accounted for by biological sex and temporal structure on different timescales. Intraindividual variability in PA was represented by the consecutive disparity index. ResultsFemale individuals (regardless of whether they had menstrual cycles) demonstrated lower intraindividual variability in PA than male individuals (Kruskal-Wallis H=29.51; P<.001). Furthermore, individuals with menstrual cycles did not have greater intraindividual variability than those without menstrual cycles (Kruskal-Wallis H=0.54; P=.46). PA rhythms differed at the weekly timescale: individuals with increased or decreased PA on weekends had larger intraindividual variability (Kruskal-Wallis H=10.13; P=.001). In addition, intraindividual variability differed by decade of life, with older age groups tending to have less variability in PA (Kruskal-Wallis H=40.55; P<.001; Bonferroni-corrected significance threshold for 15 comparisons: P=.003). A generalized additive model predicting the consecutive disparity index of 24-hour metabolic equivalent of task sums (intraindividual variability of PA) showed that sex, age, and weekly rhythm accounted for only 11% of the population variability in intraindividual PA variability. ConclusionsThe exclusion of people from PA research based on their biological sex, age, the presence of menstrual cycles, or the presence of weekly rhythms in PA is not supported by our analysis.

Objectives Major depressive disorder (MDD) is a critical health issue that is inadequately addressed with currently available treatments, indicating a need for novel treatment approaches. This case report describes a patient’s outcomes after completing an integrated mind-body depression intervention that combined cognitive-behavioral therapy (CBT) administered by a clinician with whole-body hyperthermia (WBH) administered using an infrared sauna device. Methods The patient, a 37-year-old adult male who identified as agender and Asian, completed eligibility screening and a baseline assessment that included a semi-structured clinical interview and self-report measures of mood and emotional health. The intervention included eight weekly 1-hour CBT sessions and eight weekly WBH sessions. Before each CBT session, the patient completed the Beck Depression Inventory-II (BDI-II). After the patient completed all intervention sessions, we re-assessed the patient’s mood and cognitive and emotional health and collected verbal feedback about their treatment experience. Results At baseline, the patient met the criteria for diagnosis of MDD per the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, and they were not receiving any form of treatment. From initial contact to the final assessment (14 weeks), the patient evidenced a 25-point reduction on the BDI-II from a score of 28 to 3, reflecting a clinically meaningful decrease from severe depressive symptoms to remission. At the final assessment, the patient no longer met the criteria for MDD. Conclusions For this patient, this relatively brief integrative depression treatment was both feasible and efficacious. The patient achieved depression remission in fewer than 14 weeks. These results warrant greater exploration into the potential benefits of this integrative depression treatment.

OBJECTIVE:To pilot the use of a wearable consumer sleep technology (CST) for continuous, longitudinal assessment of sleep and cardiac metrics in patients undergoing hypoglossal nerve stimulation (HNS) uptitration for obstructive sleep apnea (OSA). METHODS:In this case series, participants implanted at a tertiary care center with HNS used a CST (Oura Ring) nightly, beginning at device activation through uptitration for 4 months. CST outcome metrics included total sleep time (TST), wake time after sleep onset (WASO), average heart rate (AvHR), heart rate variability (HRV), sleep efficiency, and latency. These metrics were evaluated using univariate and multivariate regression models controlling for age, sex, baseline apnea-hypopnea index (AHI), and body mass index (BMI). RESULTS:Fourteen participants had data on longitudinal HNS use and CST sleep data collected from an average of 106 ± 47 nights per participant (total 1478 nights of data). Higher HNS amplitudes were significantly associated with decreased WASO (p = 0.002), decreased AvHR (p < 0.001), and decreased HRV (p < 0.001). TST increased significantly over time but was not associated with HNS amplitude change. Multivariate analysis of a subgroup showed significant associations between HNS amplitude increases and a decline in WASO (p = 0.047) and reductions in AvHR and HRV (p = 0.044, p = 0.021). CONCLUSION:HNS uptitration may be associated with changes in WASO, AvHR, and HRV as tracked longitudinally over 4 months by a wearable CST. HNS uptitration was associated with changes in WASO, AvHR, and HRV. Future studies are needed to understand the effects of HNS therapy on sleep metrics and explore the clinical utility of CST in the paradigm of HNS therapy delivery and outcomes. LEVEL OF EVIDENCE: 4:

Objective: Stress is a driver of depression, and people with depression often struggle to cope with stress and anxiety. This study directly compares the mental health effects of a Wim Hof Method intervention to an active control condition (slow breathing) in women with high stress and high depressive symptoms. Methods: We randomized 84 healthy midlife women with high stress and high depressive symptoms to either: 1) the hormetic stress condition based on the Wim Hof Method (WHM) involving a breathing technique designed to induce intermittent hypoxia and cold showers (n = 41) or 2) an active comparison condition involving slowpaced breathing and warm showers (n = 43). We provided participants with daily audio instructions (15 min) for three weeks during the COVID-19 pandemic (2020-2021). Our primary outcomes were depressive symptoms, anxiety symptoms, and perceived stress collected at pre-intervention, post-intervention, and 3 months later. We also assessed daily stress rumination and affect with daily diary during the intervention, and participants completed a laboratory stressor, the Trier Social Stress Test, before and after the intervention, and provided samples for salivary cortisol reactivity. Results: Participants in the active control condition perceived the intervention to be more credible and expected greater mental wellbeing benefits compared to those in the Wim Hof Method condition. Differential attrition was observed with six participants (7 %) dropping out - all from WHM condition. Among the participants who completed the intervention, both groups improved on mental health outcomes immediately after the intervention with a 24 % reduction in depressive symptoms, a 27 % reduction in anxiety symptoms, and 20 % reduction in perceived stress. Improvements were maintained at the 3-month follow-up with 46 % of the sample reporting mild or no depressive symptoms. Participants in the WHM condition had significant reductions in rumination after daily stressful events compared to those in the active control group. Both conditions had reduced daily negative affect across the intervention and lower peak cortisol reactivity to the lab stressor post-intervention. Conclusions: Counter to the preregistered predictions, and despite participants' differing expectations, the interventions led to equivalent reductions in depressive symptoms, anxiety symptoms, and perceived stress, which were sustained at three months. They also produced comparable reductions in cortisol reactivity and daily negative affect. However, the WHM condition was associated with greater reduction in reported rumination after daily stressful events than the active control, a finding that needs replication with larger and more diverse samples.

BACKGROUND:Concern about side effects is a common reason for SARS-CoV-2 vaccine hesitancy. OBJECTIVE:To determine whether short-term side effects of SARS-CoV-2 messenger RNA (mRNA) vaccination are associated with subsequent neutralizing antibody (nAB) response. DESIGN:Prospective cohort study. SETTING:San Francisco Bay Area. PARTICIPANTS:Adults who had not been vaccinated against or exposed to SARS-CoV-2, who then received 2 doses of either BNT162b2 or mRNA-1273. MEASUREMENTS:Serum nAB titer at 1 month and 6 months after the second vaccine dose. Daily symptom surveys and objective biometric measurements at each dose. RESULTS:363 participants were included in symptom-related analyses (65.6% female; mean age, 52.4 years [SD, 11.9]), and 147 were included in biometric-related analyses (66.0% female; mean age, 58.8 years [SD, 5.3]). Chills, tiredness, feeling unwell, and headache after the second dose were each associated with 1.4 to 1.6 fold higher nAB at 1 and 6 months after vaccination. Symptom count and vaccination-induced change in skin temperature and heart rate were all positively associated with nAB across both follow-up time points. Each 1 °C increase in skin temperature after dose 2 was associated with 1.8 fold higher nAB 1 month later and 3.1 fold higher nAB 6 months later. LIMITATIONS:The study was conducted in 2021 in people receiving the primary vaccine series, making generalizability to people with prior SARS-CoV-2 vaccination or exposure unclear. Whether the observed associations would also apply for neutralizing activity against non-ancestral SARS-CoV-2 strains is also unknown. CONCLUSION:Convergent self-report and objective biometric findings indicate that short-term systemic side effects of SARS-CoV-2 mRNA vaccination are associated with greater long-lasting nAB responses. This may be relevant in addressing negative attitudes toward vaccine side effects, which are a barrier to vaccine uptake. PRIMARY FUNDING SOURCE:National Institute on Aging.

There is urgent need for novel antidepressant treatments that confer therapeutic benefits via engagement with identified mechanistic targets. The objective of the study was to determine whether activation of the classical anti-inflammatory interleukin-6 signaling pathways is associated with the antidepressant effects of whole-body hyperthermia. A 6-week, randomized, double-blind study compared whole-body hyperthermia with a sham condition in a university-based medical center. Medically healthy participants aged 18-65 years who met criteria for major depressive disorder, were free of psychotropic medication use, and had a baseline 17-item Hamilton Depression Rating Scale score >= 16 were randomized with 1-to-1 allocation in blocks of 6 to receive whole-body hyperthermia or sham. Of 338 individuals screened, 34 were randomized, 30 received interventions and 26 had >= 2 blood draws and depressive symptom assessments. Secondary data analysis examined change in the ratio of IL-6:soluble IL-6 receptor pre-intervention, post-intervention, and at weeks 1 and 4. Hierarchical linear modeling tested whether increased IL-6:soluble IL-6 receptor ratio post-intervention was associated with decreased depressive symptom at weeks 1, 2, 4 and 6 for those randomized to whole-body hyperthermia. Twenty-six individuals were randomized to whole-body hyperthermia [n = 12; 75 % female; age = 37.9 years (SD = 15.3) or sham [n = 14; 57.1 % female; age = 41.1 years (SD = 12.5). When compared to the sham condition, active whole-body hyperthermia only increased the IL-6:soluble IL-6 receptor ratio post-treatment [F(3,72) = 11.73, p < .001], but not pre-intervention or at weeks 1 and 4. Using hierarchical linear modeling, increased IL-6:sIL-6R ratio following whole-body hyperthermia moderated depressive symptoms at weeks 1, 2, 4 and 6, such that increases in the IL-6:soluble IL-6 receptor ratio were associated with decreased depressive symptoms at weeks 1, 2, 4 and 6 for those receiving the active whole-body hyperthermia compared to sham treatment (B = -229.44, t = -3.82, p < .001). Acute activation of classical intereukin-6 signaling might emerge as a heretofore unrecognized novel mechanism that could be harnessed to expand the antidepressant armamentarium.

Commercially available wearable devices (wearables) show promise for continuous physiological monitoring. Previous works have demonstrated that wearables can be used to detect the onset of acute infectious diseases, particularly those characterized by fever. We aimed to evaluate whether these devices could be used for the more general task of syndromic surveillance. We obtained wearable device data (Oura Ring) from 63,153 participants. We constructed a dataset using participants’ wearable device data and participants’ responses to daily online questionnaires. We included days from the participants if they (1) completed the questionnaire, (2) reported not experiencing fever and reported a self-collected body temperature below 38 °C (negative class), or reported experiencing fever and reported a self-collected body temperature at or above 38 °C (positive class), and (3) wore the wearable device the nights before and after that day. We used wearable device data (i.e., skin temperature, heart rate, and sleep) from the nights before and after participants’ fever day to train a tree-based classifier to detect self-reported fevers. We evaluated the performance of our model using a five-fold cross-validation scheme. Sixteen thousand, seven hundred, and ninety-four participants provided at least one valid ground truth day; there were a total of 724 fever days (positive class examples) from 463 participants and 342,430 non-fever days (negative class examples) from 16,687 participants. Our model exhibited an area under the receiver operating characteristic curve (AUROC) of 0.85 and an average precision (AP) of 0.25. At a sensitivity of 0.50, our calibrated model had a false positive rate of 0.8%. Our results suggest that it might be possible to leverage data from these devices at a public health level for live fever surveillance. Implementing these models could increase our ability to detect disease prevalence and spread in real-time during infectious disease outbreaks.

OBJECTIVES:Obstructive sleep apnea (OSA) is usually assessed at discrete and infrequent timepoints. Wearable consumer sleep technologies (CST) may allow for more granular and longitudinal assessments of OSA therapy responses and OSA-related symptoms. METHODS:In this case series, we enrolled hypoglossal nerve stimulator (HGNS) patients who had an effective treatment response for an 8-week study using a wearable CST. Participants started with "HGNS-on," were randomized to turn off HGNS therapy during either week 4 or 5 ("HGNS-off"), followed by a return to therapy, "HGNS-resume." Participants completed validated symptom questionnaires assessing sleepiness, insomnia symptoms, functional status, and overall sleep health (Satisfaction, Alertness, Timing, Efficiency, and Duration, SATED) each week. CST metrics and survey scores were compared between HGNS treatment phases. Associations between CST metrics and survey scores were assessed. RESULTS:Seven participants with a total of 304 nights of CST data showed no statistically significant changes in total sleep time (TST), wake time after sleep onset, or sleep efficiency (SE) across the study periods. During HGNS-off, survey scores indicated significantly worsened OSA-related symptom scores. Two participants had significantly higher heart rate variability (HRV) during HGNS-off (by 3.3 and 6.3 ms) when compared to HGNS active therapy periods. Amongst CST metrics, SATED scores correlated with TST (r = 0.434, p < 0.0001), HRV (r = -0.486, p < 0.0001), and SE (r = 0.320, = 0.0014). In addition, FOSQ-10 scores correlated with average HR during sleep (r = -0.489, p < 0.001). CONCLUSION:A 1-week HGNS therapy withdrawal period impacted OSA-related sleep symptoms. Sleep-related metrics measured by a wearable CST correlated with symptom scores indicating potential value in the use of CSTs for longitudinal sleep-tracking in OSA patients. LEVEL OF EVIDENCE:4 Laryngoscope, 134:3406-3411, 2024.

Large-scale wearable datasets are increasingly being used for biomedical research and to develop machine learning (ML) models for longitudinal health monitoring applications. However, it is largely unknown whether biases in these datasets lead to findings that do not generalize. Here, we present the first comparison of the data underlying multiple longitudinal, wearable-device-based datasets. We examine participant-level resting heart rate (HR) from four studies, each with thousands of wearable device users. We demonstrate that multiple regression, a community standard statistical approach, leads to conflicting conclusions about important demographic variables (age vs resting HR) and significant intra- and inter-dataset differences in HR. We then directly test the cross-dataset generalizability of a commonly used ML model trained for three existing day-level monitoring tasks: prediction of testing positive for a respiratory virus, flu symptoms, and fever symptoms. Regardless of task, most models showed relative performance loss on external datasets; most of this performance change can be attributed to concept shift between datasets. These findings suggest that research using large-scale, pre-existing wearable datasets might face bias and generalizability challenges similar to research in more established biomedical and ML disciplines. We hope that the findings from this study will encourage discussion in the wearable-ML community around standards that anticipate and account for challenges in dataset bias and model generalizability.

Background: There is a pressing need for effective treatments for major depressive disorder (MDD).ObjectiveTo examine the feasibility of an integrated mind-body MDD treatment combining cognitive behavioral therapy (CBT) and whole-body hyperthermia (WBH).MethodsIn this single-arm trial, 16 adults with MDD initially received 8 weekly CBT sessions and 8 weekly WBH sessions. Outcomes included WBH sessions completed (primary), self-report depression assessments completed (secondary), and pre-post intervention changes in depression symptoms (secondary). We also explored changes in mood and cognitive processes and assessed changes in mood as predictors of overall treatment response.ResultsThirteen participants (81.3%) completed >= 4 WBH sessions (primary outcome); midway through the trial, we reduced from 8 weekly to 4 bi-weekly WBH sessions to increase feasibility. The n = 12 participants who attended the final assessment visit completed 100% of administered self-report depression assessments; all enrolled participants (n = 16) completed 89% of these assessments. Among the n = 12 who attended the final assessment visit, the average pre-post-intervention BDI-II reduction was 15.8 points (95% CI: -22.0, -9.70), p = 0.0001, with 11 no longer meeting MDD criteria (secondary outcomes). Pre-post intervention improvements in negative automatic thinking, but not cognitive flexibility, achieved statistical significance. Improved mood from pre-post the initial WBH session predicted pre-post treatment BDI-II change (36.2%; rho = 0.60, p = 0.038); mood changes pre-post the first CBT session did not.LimitationsSmall sample size and single-arm design limit generalizability.ConclusionAn integrated mind-body intervention comprising weekly CBT sessions and bi-weekly WBH sessions was feasible. Results warrant future larger controlled clinical trials.Clinivaltrials.gov Registration: NCT05708976ConclusionAn integrated mind-body intervention comprising weekly CBT sessions and bi-weekly WBH sessions was feasible. Results warrant future larger controlled clinical trials.Clinivaltrials.gov Registration: NCT05708976

Objective: The reward-based eating drive (RED) scales are well-established self-report scales that measure reward-related eating behavior. However, German versions of the RED has not yet been created and validated. Therefore, the aim of the present study was to develop and psychometrically evaluate a German version of the RED. Method: A German university sample (N=311 medical undergraduates) completed a survey including the RED-9 and the RED-13, as well as several related measures, to test the established factor structure using a confirmatory factor analysis. Construct validity was assessed by correlation analysis with standardized and internationally established questionnaires measuring reward-related eating. Results: The German 9-item RED (RED-9) with the 3-factor model showed the best psychometric properties in terms of fit indices with acceptable internal consistency, good item rest correlation, and good construct validity with other reward eating scales. There was also a positive association between the German RED-9 total score and BMI. Conclusions: In conclusion, the German RED-9 is a valid and reliable instrument for the assessment of reward-related eating behavior in non-pathological populations. Further research is needed to better understand associations among reward-related eating, obesity, and diabetes in the German population.

Sleep monitoring has become widespread with the rise of affordable wearable devices. However, converting sleep data into actionable change remains challenging as diverse factors can cause combinations of sleep parameters to differ both between people and within people over time. Researchers have attempted to combine sleep parameters to improve detecting similarities between nights of sleep. The cluster of similar combinations of sleep parameters from a night of sleep defines that night’s sleep phenotype. To date, quantitative models of sleep phenotype made from data collected from large populations have used cross-sectional data, which preclude longitudinal analyses that could better quantify differences within individuals over time. In analyses reported here, we used five million nights of wearable sleep data to test (a) whether an individual’s sleep phenotype changes over time and (b) whether these changes elucidate new information about acute periods of illness (e.g., flu, fever, COVID-19). We found evidence for 13 sleep phenotypes associated with sleep quality and that individuals transition between these phenotypes over time. Patterns of transitions significantly differ (i) between individuals (with vs. without a chronic health condition; chi-square test; p-value < 1e−100) and (ii) within individuals over time (before vs. during an acute condition; Chi-Square test; p-value < 1e−100). Finally, we found that the patterns of transitions carried more information about chronic and acute health conditions than did phenotype membership alone (longitudinal analyses yielded 2–10× as much information as cross-sectional analyses). These results support the use of temporal dynamics in the future development of longitudinal sleep analyses.

Algorithms for the detection of COVID-19 illness from wearable sensor devices tend to implicitly treat the disease as causing a stereotyped (and therefore recognizable) deviation from healthy physiology. In contrast, a substantial diversity of bodily responses to SARS-CoV-2 infection have been reported in the clinical milieu. This raises the question of how to characterize the diversity of illness manifestations, and whether such characterization could reveal meaningful relationships across different illness manifestations. Here, we present a framework motivated by information theory to generate quantified maps of illness presentation, which we term “manifestations,” as resolved by continuous physiological data from a wearable device (Oura Ring). We test this framework on five physiological data streams (heart rate, heart rate variability, respiratory rate, metabolic activity, and sleep temperature) assessed at the time of reported illness onset in a previously reported COVID-19-positive cohort (N = 73). We find that the number of distinct manifestations are few in this cohort, compared to the space of all possible manifestations. In addition, manifestation frequency correlates with the rough number of symptoms reported by a given individual, over a several-day period prior to their imputed onset of illness. These findings suggest that information-theoretic approaches can be used to sort COVID-19 illness manifestations into types with real-world value. This proof of concept supports the use of information-theoretic approaches to map illness manifestations from continuous physiological data. Such approaches could likely inform algorithm design and real-time treatment decisions if developed on large, diverse samples.

Identifying malleable influences on eating behaviours will advance our ability to improve physical and mental health. Food-related emotional expectancies are the anticipated positive and negative emotions from eating different foods and are theorised to affect eating behaviour, and to be amenable to change. The Anticipated Effects of Food Scale (AEFS) assesses food-related emotional expectancies using 62 one-word items; however, a shorter questionnaire would be useful in large and clinical studies. In the present study, we developed a brief version of the AEFS, named the AEFS-Brief (AEFS-B), using a data-driven approach. We identified candidate items from all-subset correlations with the AEFS and item-level correlations with eating behaviours in two community samples (n = 247, n = 718), and we assessed internal consistency and validity of the AEFS-B. We further assessed internal consistency and validity in two independent samples (n = 200, n = 108) that completed a 'bogus' taste test or 24-h dietary recalls. Results indicated that the AEFS-B with 28 one-word items had good internal consistency and convergent validity with the AEFS. Analysis with AEFS-B scores reproduced associations of AEFS scores with intake of added sugars, symptoms of food addiction, eating to cope motives, and ad libitum food intake. We also demonstrated novel associations of AEFS and AEFS-B scores with emotional eating and diet quality. The AEFS-B appears to be a reliable and valid brief measure of food-related emotional expectancies that can be used in cohort and population studies, ecological momentary assessments, and for clinical populations in which participant burden is high.

Correlations between altered body temperature and depression have been reported in small samples; greater confidence in these associations would provide a rationale for further examining potential mechanisms of depression related to body temperature regulation. We sought to test the hypotheses that greater depression symptom severity is associated with (1) higher body temperature, (2) smaller differences between body temperature when awake versus asleep, and (3) lower diurnal body temperature amplitude. Data collected included both self-reported body temperature (using standard thermometers), wearable sensor-assessed distal body temperature (using an off-the-shelf wearable sensor that collected minute-level physiological data), and self-reported depressive symptoms from > 20,000 participants over the course of ~ 7 months as part of the TemPredict Study. Higher self-reported and wearable sensor-assessed body temperatures when awake were associated with greater depression symptom severity. Lower diurnal body temperature amplitude, computed using wearable sensor-assessed distal body temperature data, tended to be associated with greater depression symptom severity, though this association did not achieve statistical significance. These findings, drawn from a large sample, replicate and expand upon prior data pointing to body temperature alterations as potentially relevant factors in depression etiology and may hold implications for development of novel approaches to the treatment of major depressive disorder.