Evaluation of the Chrononutrition Profile - Questionnaire in an online community sample of adults.

Chrononutrition (i.e., circadian timing of food intake) has been linked to indicators of health status such as body weight and insulin resistance. A measure of general chrononutrition patterns, the Chrononutrition Profile - Questionnaire, has been developed and preliminary evidence of validity and reliability of the measure has been documented in a homogenous group of undergraduates. However, this measure has not yet been validated in an online, community-based sample. The present study therefore aimed to evaluate the validity of the Chrononutrition Profile - Questionnaire in a web-based community sample. Analyses suggested that the Chrononutrition Profile - Questionnaire displays acceptable validity for use in diverse community samples of adults, with moderate to strong correlations (r = 0.39-0.91) between the Chrononutrition Profile - Questionnaire and measures of dietary intake and sleep. This measure is suitable for use in a variety of settings, by stakeholders and scientists, and may contribute to future development of health behavior interventions and research programs centered around chrononutrition.

Development and validation of the Chrononutrition Profile - Diary.

The circadian timing of food intake (i.e., chrononutrition) has been linked to various markers of health status, such as body weight and insulin sensitivity. However, a valid assessment of day-to-day, within-person patterns in chrononutrition has not yet been developed. This paper details the development and initial validity testing of the Chrononutrition Profile - Diary (CP-D). The CP-D assesses 6 components of chrononutrition that are likely to influence health (breakfast skipping, largest meal, evening eating, evening latency, night eating, and eating window). This measure demonstrated preliminary evidence of convergent validity with the ASA24 (Automated Self-Administered 24-hour dietary assessment tool). The CP-D is designed for use by both healthcare professionals and researchers. It can serve as an independent assessment of day-to-day patterns of chrononutrition, and can also be used along with existing dietary measures to provide a comprehensive assessment of participants' and patients' daily eating behaviors and meal timing patterns.

Temporal Associations Between Daytime Napping and Nocturnal Sleep: An Exploration of Random Slopes.

BACKGROUND: Restricting daytime naps is a common sleep hygiene recommendation to improve nocturnal sleep, but research on whether napping is related to sleep is mixed. The current literature is limited in that day level, bidirectional associations have not been tested in college students, and existing studies have not sufficiently examined the role of individual differences in these daily associations. PURPOSE: The current study addressed these limitations by assessing the temporal associations between self-reported daytime nap duration and objectively assessed nocturnal sleep, and whether these associations were moderated by chronotype or nap frequency, in college students. METHODS: Participants (N = 384) self-reported nap duration and wore an actiwatch to measure nocturnal sleep for 14 consecutive days and nights. Mixed linear models were used to test the daily associations between daytime nap duration and total sleep time (TST), sleep onset latency (SOL), sleep efficiency (SE), and wake after sleep onset (WASO). In addition, random slope modeling was used to test whether these associations significantly varied between participants. RESULTS: Longer nap duration was significantly associated with greater WASO, lower SE, and longer SOL. Shorter TST, shorter WASO, and greater SE were related to longer next-day nap duration. CONCLUSIONS: There were several significant associations between daytime napping and nocturnal sleep, and nap frequency significantly moderated the association between TST and next-day nap duration. Future research should test daily and contextual moderators of daytime napping and nocturnal sleep, which could refine sleep hygiene efforts by identifying individuals for whom recommendations would be most helpful.

The theory of planned behaviour and sleep opportunity: An ecological momentary assessment.

Many American adolescents and adults report that they are not meeting sleep duration recommendations. Although insufficient sleep duration can occur due to factors outside an individual's direct control, many individuals choose to restrict their own sleep. The theory of planned behaviour (TPB) offers a framework to study this phenomenon. Recent research efforts have used the TPB to study sleep and have demonstrated success predicting sleep-related intentions and behaviour but have failed to consider volitional sleep behaviour or consider between- and within-person differences. The present study used an intensive longitudinal design to test how constructs of the TPB relate to nightly sleep opportunity. Healthy college students (N = 79) participated in a weeklong study in which they completed four ecological momentary assessment signals per day that measured their attitudes, subjective norms, perceived behavioural control, and intentions relating to their nocturnal sleep opportunity. Participants wore an actiwatch each night of the study to measure their sleep opportunity. Mixed linear models found that both intentions and perceived behavioural control were significant predictors of subsequent sleep opportunity, and that perceived behaviour control was the strongest within-day predictor of intentions. Results demonstrate that within-person changes in perceived behavioural control and intentions predict subsequent sleep opportunity and provide insight into the potential refinement of sleep promotion efforts.

The impact of circadian timing on energy balance: an extension of the energy balance model.

A significant proportion of the population is classified as having overweight or obesity. One framework which has attempted to explain biobehavioral mechanisms influencing the development of overweight and obesity is the energy balance model. According to this model, the body continually attempts to balance energy intake with energy expenditure. When energy intake and energy expenditure become imbalanced, there is an increase in homeostatic and allostatic pressure, generally to either increase energy intake or decrease energy expenditure, so as to restore energy homeostasis.Recent research has indicated that circadian aspects of energy intake and energy expenditure may influence energy balance. This paper provides a narrative review of existing evidence of the role of circadian timing on components of energy balance. Research on the timing of food intake, physical activity, and sleep indicates that unhealthy timing is likely to increase risk of weight gain. Public health guidelines focus on how much individuals eat and sleep, what foods are consumed, and the type and frequency of exercise, but the field of circadian science has begun to demonstrate that when these behaviors occur may also influence overweight and obesity prevention and treatment efforts.

Intraindividual Variability of Sleep Opportunity Attitudes, Perceived Norms, Perceived Behavioral Control, and Intentions.

BACKGROUND: Recent research has used the theory of planned behavior (TPB) to predict sleep. However, this research has focused on between-person effects and has failed to capture the intraindividual variability of sleep-related attitudes, subjective norms, perceived behavioral control, and intentions. PURPOSE: The current study sought to characterize the between- and within-day patterns of these constructs. METHODS: Participants (N = 79) completed a 1 week ecological momentary assessment protocol in which they reported their attitudes, subjective norms, perceived behavioral control, and intentions toward nightly sleep opportunity four times per day. RESULTS: Analyses revealed both between- and within-day variability of these constructs, with perceived behavioral control and intentions demonstrating greater variability than attitudes and subjective norms. Mixed linear models revealed that attitudes and subjective norms significantly increased throughout the week, while perceived behavioral control and intentions significantly decreased throughout the day. CONCLUSIONS: The between- and within-day patterns of the TPB constructs highlight important methodological considerations and provide insight into the potential refinement of sleep promotion efforts.

Big 5 personality traits and intraindividual variability in sleep duration, continuity, and timing.

OBJECTIVES: The personality traits of conscientiousness and neuroticism have been consistently linked to mean-level, self-reported sleep duration and continuity. The present study expands this literature by using actigraphy sleep assessment to examine how personality is related to both mean-level and the intraindividual variability in sleep duration, continuity, and timing. DESIGN: One-week ecological sleep assessment. SETTING: The research was conducted at a mid-size Midwestern university. Actigraphy data were collected at participants' homes. PARTICIPANT: The study had a sample size of 358 college-aged participants. MEASUREMENTS: Sleep duration, continuity, and timing were assessed for 7 consecutive nights using actigraphy. Participants also completed a self-report assessment of personality. RESULTS: Conscientiousness and extraversion emerged as the key personality predictors of sleep outcomes. Higher conscientiousness was associated with longer average sleep duration and earlier timing, as well as higher consistency in total sleep time. Higher extraversion was associated with later bedtimes, less total sleep time, and more variability in their sleep timing. Neuroticism, agreeableness, and openness to experience were not significantly related to sleep. CONCLUSION: The study's results highlight the importance of personality in sleep research, with implications for sleep health promotion efforts.

An examination of eating misalignment: The discrepancy between preferred and actual timing of food intake.

Both internal (e.g., preferences) and external (e.g., social) factors guide chrononutrition (i.e., the timing of food intake), but the nature and variability of chrononutrition preferences (i.e., preferred timing of food intake) have not been empirically evaluated. The present study aimed to characterize the variability and range of chrononutrition preferences and to evaluate the extent of eating misalignment, defined as the discrepancy between chrononutrition preferences and chrononutrition behaviors. 192 undergraduate students aged 18 to 31 years self-enrolled in an online questionnaire study. Participants provided demographic information and completed the Chrononutrition Profile - Questionnaire to evaluate chrononutrition preferences, chrononutrition behaviors, and eating misalignment. Results indicated high inter-individual variability in chrononutrition preferences and eating misalignment, with extreme cases of eating misalignment across all chrononutrition facets. This study is the first to confirm that when individuals want to eat may differ from when they actually eat. With additional research, these constructs may be meaningful to consider, together with other aspects of chrononutrition, in the development of future chrononutrition-based intervention efforts.

The Process of Developing a Sleep Health Improvement Plan: a Lab-Based Model of Self-Help Behavior.

BACKGROUND: Although self-help strategies to improve sleep are widely accessible, little is known about the ways in which individuals interact with these resources and the extent to which people are successful at improving their own sleep based on sleep health recommendations. The present study developed a lab-based model of self-help behavior by observing the development of sleep health improvement plans (SHIPs) and examining factors that may influence SHIP development. METHOD: Sixty healthy, young adults were identified as poor sleepers during one week of actigraphy baseline and recruited to develop and implement a SHIP. Participants viewed a list of sleep health recommendations through an eye tracker and provided information on their current sleep health habits. Each participant implemented their SHIP for 1 week during which sleep was assessed with actigraphy. RESULTS: Current sleep health habits, but not patterns of visual attention, predicted SHIP goal selection. Sleep duration increased significantly during the week of SHIP implementation. CONCLUSIONS: Findings indicate that the SHIP protocol is an effective strategy for observing self-help behavior and examining factors that influence goal selection. The increase in sleep duration suggests that individuals may be successful at extending their own sleep, though causal mechanisms have not yet been established. This study presents a lab-based protocol for studying self-help sleep improvement behavior and takes an initial step toward gaining knowledge required to improve sleep health recommendations.

The effect of caffeine abstinence on sleep among habitual caffeine users with poor sleep.

Caffeine is the most widely used psychoactive substance in the world and is known to disrupt healthy sleep. However, very few studies have directly tested the effect of caffeine abstinence on sleep, and these have yielded inconsistent findings. The purpose of the present study was to examine changes in sleep following caffeine abstinence and examine the extent to which characteristics of habitual caffeine use moderated this change. Participants included 66 healthy, young adults with habitual caffeine use and poor sleep. During the 2-week baseline, sleep was assessed using wrist actigraphy and daily caffeine use was assessed with bedtime diaries. Eligible participants then completed 1 week of caffeine abstinence, during which sleep was measured with wrist actigraphy. Multilevel models found no significant differences between either mean levels or growth trajectories of total sleep time or sleep efficiency between baseline and caffeine abstinence. Mean levels of sleep onset latency also did not differ between baseline and caffeine abstinence. A small but significant quadratic effect was observed, such that sleep onset latency decreased during the first few days of caffeine abstinence, then increased to levels above baseline. Characteristics of caffeine use did not moderate changes in sleep between baseline and caffeine abstinence. These data suggest that abstaining from caffeine may not result in long-term sleep improvement for habitual caffeine users, which contradicts the common sleep health recommendation. The present findings encourage more rigorous investigation of the effectiveness of caffeine restriction on sleep.

Effect of smoke exposure on young adults' sleep quality.

In this study, we aimed to examine the relationship between active smoking and environmental tobacco smoke exposure on sleep-quality complaints. In total, 1023 young adult participants completed online surveys. Based on these surveys, participants were classified into three groups according to their level of smoke exposure (low, moderate, high). An analysis of covariance revealed that, after controlling for sex, participants with high and moderate smoke exposure reported more sleep complaints than those with low exposure. Among non-smokers, hierarchical linear regression indicated that environmental tobacco smoke exposure was positively associated with sleep complaints. Improved understanding of modifiable risk factors for young adults' poor sleep quality, such as smoke exposure, could enable lifestyle changes that might lay the foundation for improved health at later life stages.

Application of health behaviour theory to sleep health improvement.

Although sleep hygiene is often used for broad sleep health promotion efforts, sleep hygiene education programmes are largely ineffective. These programmes are limited by their lack of a theoretical foundation. Health behaviour theory (HBT) has been used for decades to successfully predict and modify many health behaviours, but its use in the study of sleep health is rare. The purpose of this review is threefold. First, four dominant HBTs will be introduced. Second, the brief literature on HBT and sleep health will be reviewed. Lastly, a translational research agenda will be proposed. The present review concludes that HBT shows potential in both the prediction and modification of sleep health, and that there are several short- and long- term research goals to advance these efforts.

Development, validation and reliability of the Chrononutrition Profile - Questionnaire.

Chrononutrition, or the circadian timing of food intake, has garnered attention as a topic of study due to its associations with health (e.g. weight gain); however, a valid and reliable assessment of chrononutrition in daily life has not yet been developed. This paper details the development and initial reliability and validity testing of the Chrononutrition Profile - Questionnaire (CP-Q). The CP-Q assesses six components of chrononutrition that are likely to influence health (breakfast skipping, largest meal, evening eating, evening latency, night eating, and eating window). This questionnaire is designed to assess general chrononutrition behaviors and preferred timing of food intake. The CP-Q can be used as a sole evaluation of chrononutrition, and can also be utilized in conjunction with existing dietary measures to provide a comprehensive assessment of one's eating behaviors. This measure offers health-care professionals, researchers, and stakeholders a cost-effective and comprehensive method of evaluating chrononutrition and identifying targets for health improvement.

Daily Associations Between Sleep and Physical Activity.

BACKGROUND: Research has demonstrated a correlational relationship between sleep and physical activity, though this work has been largely cross sectional and fails to demonstrate temporal relationships. The purpose of this study was to test the daily, bidirectional relationships between sleep and physical activity, and whether this varied between weekdays and weekend days. METHOD: Fifty-four healthy, young adults wore a Fitbit Flex to measure sleep and physical activity during a 6-day study period. RESULTS: Mixed linear models revealed that physical activity did not predict subsequent night's sleep. However, on nights when participants had longer than their own average total sleep time, and greater than their own average wake after sleep onset, this predicted less physical activity the following day. CONCLUSION: Results suggest that, in healthy young adults, physical activity may not promote healthier subsequent sleep, but sleep duration and continuity influence physical activity in their own way. Young adults may respond differently to health promotion efforts, and a greater understanding of these temporal associations can enhance the efficacy of these efforts.

Sleep and eating disorders among adults enrolled in a commercial weight loss program: associations with self-report and objective sleep measures.

PURPOSE: Some research suggests that eating disorders are related to poor sleep health. To increase knowledge on the relation between sleep and eating disorders, we used a multi-method approach to examine associations between sleep, chronotype, and eating disorder psychopathology. METHODS: We investigated associations between ED psychopathology, both diagnostic categories (ascertained through self-report data) and dimensional measures, and self-report and ambulatory measures of sleep. Adults currently enrolled in a commercial weight loss program completed self-report measures as well as 1 week of ambulatory sleep monitoring and sleep diaries. RESULTS: Participants with full- or sub-threshold bulimia nervosa and binge eating disorder reported significantly lower subjective sleep health and greater eveningness. Additionally, greater severity of eating disorder psychopathology was associated with lower subjective sleep health and greater eveningness. Eating disorder psychopathology was generally not related to objective sleep measures. Regarding diary measures, global eating disorder psychopathology was negatively correlated with subjective reports of feeling rested. CONCLUSION: Eating disorder psychopathology is associated with participants' subjective sense of sleep quality, but appears to have little relation to objective sleep characteristics. Level of evidence Level V, descriptive study.

Associations Between Sleep and Health-Risk Behaviors in a Rural Adolescent Population.

INTRODUCTION: Insufficient sleep has been associated with engagement in a number of health-risk behaviors in adolescents, including substance use and sexual activity. Associations between sleep and health-risk behaviors in adolescents living in rural areas of the United States are not well investigated. In rural settings, adolescents' sleep patterns, lifestyle factors, and health-risk opportunities may differ from those of urban adolescents, making the independent study of sleep and health behavior associations necessary. METHOD: This study examined data from the Rural Adolescent Health Survey (N = 322) administered in rural North Dakota. RESULTS: Rural adolescents who reported engaging in smoking, alcohol use, or drug use slept significantly less than adolescents who did not report engaging in these activities. DISCUSSION: Sleep was not associated with chewing tobacco use or risky sexual activity, which may reflect an effect of rural cultural values on sleep and health-risk behavior associations.

Avoidant Coping and Poor Sleep Efficiency in Dementia Caregivers.

OBJECTIVES: Caring for a spouse with dementia is a source of chronic stress and is associated with a heightened prevalence of self-reported sleep problems. Styles and strategies for coping with stress have been associated with objective measures of sleep in non-caregiver populations. The current study evaluated relationships between caregiver coping style and sleep disturbance using in-home polysomnography. METHODS: Sixty spousal caregivers (mean [standard deviation] age = 73.31 [7.05] years; 81.7% female) completed the Brief Cope, the Hamilton Rating Scale for Depression, and three nights of in-home polysomnography. Participants were categorized into two groups based on the presence or absence of clinically significant low sleep efficiency (<80%). A factor analysis of the Brief Cope yielded higher-order factors that included approach coping and avoidant coping (explained variance, 27.2% and 16.9%, respectively). Coping factors were entered into a binary logistic regression predicting sleep efficiency group while controlling for sleep apnea, medication use, and depression, as measured by the Hamilton Rating Scale for Depression. RESULTS: In fully adjusted models, for each unit increase on the avoidant coping factor, participants were 3.4 times more likely to be classified in the low sleep efficiency group (B = 1.224, χ2(1) = 4.967, p = .026, exp(B) = 3.401, 95% confidence interval = 1.159-9.981). Approach coping was unrelated to sleep efficiency in both adjusted and unadjusted models. CONCLUSIONS: These findings highlight the importance of coping among caregivers and indicate that avoidant coping may be a modifiable predictor of sleep disturbance in conditions of chronic stress.

The role of sleep hygiene in promoting public health: A review of empirical evidence.

The ineffectiveness of sleep hygiene as a treatment in clinical sleep medicine has raised some interesting questions. If it is known that, individually, each specific component of sleep hygiene is related to sleep, why wouldn't addressing multiple individual components (i.e., sleep hygiene education) improve sleep? Is there still a use for sleep hygiene? Global public health concern over sleep has increased demand for sleep promotion strategies accessible to the population. However, the extent to which sleep hygiene strategies apply outside clinical settings is not well known. The present review sought to evaluate the empirical evidence for sleep hygiene recommendations regarding exercise, stress management, noise, sleep timing, and avoidance of caffeine, nicotine, alcohol, and daytime napping, with a particular emphasis on their public health utility. Thus, our review is not intended to be exhaustive regarding the clinical application of these techniques, but rather to focus on broader applications. Overall, though epidemiologic and experimental research generally supported an association between individual sleep hygiene recommendations and nocturnal sleep, the direct effects of individual recommendations on sleep remains largely untested in the general population. Suggestions for clarification of sleep hygiene recommendations and considerations for the use of sleep hygiene in nonclinical populations are discussed.

Sleep hygiene behaviors among midlife women with insomnia or sleep-disordered breathing: the SWAN sleep study.

BACKGROUND: Insomnia and sleep-disordered breathing (SDB) are the most common sleep disorders among midlife women. Although promoting sleep hygiene behaviors may be a useful behavioral approach for the management of insomnia or SDB, the frequency with which women engage in these behaviors is unclear. METHODS: Participants were from the Study of Women's Health Across the Nation (SWAN) Sleep Study (N=321; age range=48-58 years). Out of the full sample, 10.3% (n=33) met Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition diagnostic criteria for insomnia, 15.3% (n=49) had clinically significant SDB (apnea-hypopnea index ≥15), and 4.7% (n=15) met criteria for both insomnia and SDB, resulting in an overall prevalence of 15.0% (n=48) for insomnia and 19.9% (n=64) for SDB. Participants provided diary-based assessments of sleep hygiene behaviors for 14-35 days. Two positive behaviors (sufficient exercise, regular morning out-of-bed time) and four negative behaviors (taking long daytime naps, caffeine consumption near bedtime, alcohol consumption near bedtime, smoking) were examined. These behaviors were compared between women with and without insomnia or SDB following adjustment for sociodemographic factors and mental and physical health indices. RESULTS: Women with insomnia engaged in significantly fewer negative sleep hygiene behaviors than women without insomnia (1.61±0.15 vs. 2.09±0.09 behaviors; p<0.01); specifically, women with insomnia were less likely to take long naps (odds ratio [OR]=0.30, 95% confidence interval [CI]: 0.12-0.74) or consume caffeine near bedtime (OR=0.44, 95% CI: 0.20-0.98). In contrast, women with SDB were less likely to be physically active than women without SDB (OR=0.52, 95% CI: 0.27-0.98), but no other differences in sleep hygiene behaviors were observed. CONCLUSIONS: These data suggest that insomnia in midlife women is not associated with poor sleep hygiene. Increasing physical activity may be a valuable recommendation for midlife women with SDB.