Social jet lag, chronotype and body mass index in 14-17-year-old adolescents

Eating Jet Lag: A Marker of the Variability in Meal Timing and Its Association with Body Mass Index

The timing of food intake has been associated with obesity and adverse metabolic outcomes, independently of the amount or content of food intake and activity level. However, the impact of the variability in the timing of food intake between weekends and weekdays on BMI (body mass index) remains unexplored. To address that, we propose to study a marker of the variability of meal timing on weekends versus weekdays (denominated as 'eating jet lag') that could be associated with increments in BMI. This cross-sectional study included 1106 subjects (aged 18-25 years). Linear regression models were used to examine the associations of eating jet lag with BMI and circadian related variables (including chronotype, eating duration, sleep duration, and social jet lag). Subsequently, a hierarchical multivariate regression analysis was conducted to determine whether the association of eating jet lag with BMI was independent of potentially confounding variables (e.g., chronotype and social jet lag). Moreover, restricted cubic splines were calculated to study the shape of the association between eating jet lag and BMI. Our results revealed a positive association between eating jet lag and BMI (p = 0.008), which was independent of the chronotype and social jet lag. Further analysis revealed the threshold of eating jet lag was of 3.5 h or more, from which the BMI could significantly increase. These results provided evidence of the suitability of the eating jet lag, as a marker of the variability in meal timing between weekends and weekdays, for the study of the influence of meal timing on obesity. In a long run, the reduction of the variability between meal timing on weekends versus weekdays could be included as part of food timing guidelines for the prevention of obesity among general population.

Usefulness and utilization of treatment elements from the Transdiagnostic Sleep and Circadian Intervention for adolescents with an evening circadian preference

OBJECTIVE

Existing research has demonstrated that patient ratings of usefulness and ratings of utilization of treatment elements are associated with treatment outcome. Few studies have examined this relationship among adolescents and with an extended follow-up. This study examined the extent to which elements of the Transdiagnostic Sleep and Circadian Intervention (TranS-C) were rated by youth as useful and utilized 6-months and 12-months after treatment.

METHOD

Participants were 64 adolescents with an evening circadian preference who were given TranS-C as a part of their participation in a NICHD-funded study. At 6-month and 12-month follow-up, they completed the Usefulness Scale, the Utilization Scale, a 7-day sleep diary assessing total sleep time (TST) and bedtime, and the Children's Morningness-Eveningness Preference Scale (CMEP).

RESULTS

On average, adolescents rated treatment elements as moderately useful and they utilized the treatment elements occasionally. Ratings of usefulness were associated with TST at 6-month follow-up, but not with bedtime or CMEP. Ratings of utilization were associated with a change in bedtime from 6-month to 12-month follow-up, but not with TST or CMEP. Ratings of usefulness and utilization were associated with selected treatment outcome measures at both follow-ups.

CONCLUSIONS

These findings have implications for understanding mechanisms of change following treatment.

Weight loss in conservative treatment of obesity in women is associated with physical activity and circadian phenotype: a longitudinal observational study

Introduction

The study investigates the association between circadian phenotype (CP), its stability (interdaily stability - IS) and physical activity (PA) in a weight loss (WL) programme.

Methods

Seventy-five women in WL conservative treatment (BMI ≥ 25 kg/m2) were measured (for about 3 months in between 2016 and 2018) by actigraphy.

Results

We observed a difference in time of acrophase (p = 0.049), but no difference in IS (p = 0.533) between women who lost and did not lose weight. There was a difference in PA (mesor) between groups of women who lost weight compared to those who gained weight (p = 0.007). There was a relationship between IS and PA parametres mesor: p0.001; and the most active 10 h of a day (M10): p < 0.001 - the more stable were women in their rhythm, the more PA they have. Besides confirming a relationship between PA and WL, we also found a relation between WL and CP based on acrophase. Although no direct relationship was found for the indicators of rhythm stability (IS), they can be considered very important variables because of their close connection to PA – a main factor that contributes to the success of the WL programme.

Discussion

According to the results of the study, screening of the CP and its stability may be beneficial in the creation of an individualized WL plan.

Sleep Apnea and Sleep Habits: Relationships with Metabolic Syndrome

Excess visceral adiposity is a primary cause of metabolic syndrome and often results from excess caloric intake and a lack of physical activity. Beyond these well-known etiologic factors, however, sleep habits and sleep apnea also seem to contribute to abdominal obesity and metabolic syndrome: Evidence suggests that sleep deprivation and behaviors linked to evening chronotype and social jetlag affect eating behaviors like meal preferences and eating times. When circadian rest and activity rhythms are disrupted, hormonal and metabolic regulations also become desynchronized, and this is known to contribute to the development of metabolic syndrome. The metabolic consequences of obstructive sleep apnea syndrome (OSAS) also contribute to incident metabolic syndrome. These observations, along with the first sleep intervention studies, have demonstrated that sleep is a relevant lifestyle factor that needs to be addressed along with diet and physical activity. Personalized lifestyle interventions should be tested in subjects with metabolic syndrome, based on their specific diet and physical activity habits, but also according to their circadian preference. The present review therefore focuses (i) on the role of sleep habits in the development of metabolic syndrome, (ii) on the reciprocal relationship between sleep apnea and metabolic syndrome, and (iii) on the results of sleep intervention studies.

Chronotype, Social Jet Lag, and Cardiometabolic Risk Factors in Early Adolescence

IMPORTANCE

Inadequate sleep duration and quality increase the risk of obesity. Sleep timing, while less studied, is important in adolescents because increasing evening preferences (chronotypes), early school start times, and irregular sleep schedules may cause circadian misalignment.

OBJECTIVE

To investigate associations of chronotype and social jet lag with adiposity and cardiometabolic risk in young adolescents.

DESIGN, SETTING, AND PARTICIPANTS

Starting in 1999, Project Viva recruited pregnant women from eastern Massachusetts. Mother-child in-person visits occurred throughout childhood. From January 23, 2012, to October 16, 2016, 804 adolescents aged 12 to 17 years completed 5 days or more of wrist actigraphy, questionnaires, and anthropometric measurements. A cross-sectional analysis using these data was conducted from April 31, 2018, to May 1, 2019.

EXPOSURES

Chronotype, measured via a continuous scale with higher scores indicating greater evening preferences, and social jet lag, measured as the continuous difference in actigraphy sleep midpoint in hours from midnight on weekends vs weekdays, with higher values representing more delayed sleep timing on weekends.

MAIN OUTCOMES AND MEASURES

Adiposity, measured via anthropometry and dual-energy x-ray absorptiometry. For a subset of 479 adolescents with blood samples, cardiometabolic risk scores were computed as the mean of 5 sex- and cohort-specific z scores for waist circumference, systolic blood pressure, inversely scaled high-density lipoprotein cholesterol, and log-transformed triglycerides and homeostatic model of insulin resistance.

RESULTS

Among the 804 adolescents in the study, 418 were girls and 386 were boys, with a mean (SD) age of 13.2 (0.9) years. In multivariable models adjusted for age, puberty, season, and sociodemographics, associations of chronotype and social jet lag with adiposity varied by sex. For girls, greater evening preference was associated with a 0.58-cm (95% CI, 0.12-1.03 cm; P = .04 for interaction) higher waist circumference and 0.16 kg/m2 (95% CI, 0.01-0.31 kg/m2; P = .03 for interaction) higher fat mass index as measured by dual-energy x-ray absorptiometry; each hour of social jet lag was associated with a 1.19-cm (95% CI, 0.04-2.35 cm; P = .21 for interaction) higher waist circumference and 0.45 kg/m2 (95% CI, 0.09-0.82 kg/m2; P = .01 for interaction) higher fat mass index as measured by dual-energy x-ray absorptiometry. Associations of social jet lag and evening chronotypes persisted for many measures of adiposity after adjustment for sleep duration and other lifestyle behaviors. By contrast, no associations were observed in boys. There were no associations with the cardiometabolic risk score for either sex, although statistical power was low for this outcome.

CONCLUSIONS AND RELEVANCE

Evening chronotypes and social jet lag were associated with greater adiposity in adolescent girls but not adolescent boys. Interventions aimed at improving sleep schedules may be useful for obesity prevention, especially in girls.

Social Jet Lag Associates Negatively with the Adherence to the Mediterranean Diet and Body Mass Index among Young Adults

Obesity and unhealthy eating habits have been associated with irregular sleep-wake patterns during the week, also known as social jet lag. The Mediterranean diet is a healthy pattern related with a better health and sleep quality. However, potential associations with social jet lag remain unexplored. The aim of this study was to examine whether higher social jet lag is linked to lower adherence to the Mediterranean diet and whether it is associated with BMI (Body Mass Index). This cross-sectional study included 534 young adults (18-25 years). Anthropometric parameters, adherence to the Mediterranean diet, chronotype and social jet lag were studied. Our results revealed that individuals with greater social jet lag showed lower adherence to the Mediterranean diet and had a higher BMI. Among the habits that characterized the Mediterranean dietary pattern, we observed that higher social jet lag was significantly associated with a lower intake of fruits and vegetables, as well as skipping breakfast. Hence, the promotion of regular sleep habits together with healthy dietary patterns should be considered for obesity prevention, especially among young adults.

Chronotype and Social Jetlag: A (Self-) Critical Review

The Munich ChronoType Questionnaire (MCTQ) has now been available for more than 15 years and its original publication has been cited 1240 times (Google Scholar, May 2019). Additionally, its online version, which was available until July 2017, produced almost 300,000 entries from all over the world (MCTQ database). The MCTQ has gone through several versions, has been translated into 13 languages, and has been validated against other more objective measures of daily timing in several independent studies. Besides being used as a method to correlate circadian features of human biology with other factors-ranging from health issues to geographical factors-the MCTQ gave rise to the quantification of old wisdoms, like "teenagers are late", and has produced new concepts, like social jetlag. Some like the MCTQ's simplicity and some view it critically. Therefore, it is time to present a self-critical view on the MCTQ, to address some misunderstandings, and give some definitions of the MCTQ-derived chronotype and the concept of social jetlag.

Associations between Sleep and Dietary Patterns among Low-Income Children Attending Preschool

BACKGROUND

Sleep disturbances and low-quality diets are prevalent among children in low-income settings, yet the nature of their relationship remains unclear. In particular, whether aspects other than sleep duration, including timing and quality, are associated with dietary patterns has rarely been examined, especially among preschool-aged children.

OBJECTIVE

To evaluate whether nightly and total sleep duration, sleep timing, differences in timing and duration from weekdays to weekends, and sleep quality were related to dietary patterns.

DESIGN

A cross-sectional analysis of children attending preschool. Parents completed questionnaires about children's sleep habits as well as a semiquantitative food frequency questionnaire.

PARTICIPANTS/SETTING

Three hundred fifty-four English-speaking children (49.9% boys) with no serious medical conditions aged 3 to 5 years who were enrolled in Head Start in Michigan (2009-2011) with complete information on sleep and diet.

MAIN OUTCOME MEASURES

Dietary pattern scores derived from food frequency questionnaire.

STATISTICAL ANALYSES PERFORMED

Principal component analysis was used to identify dietary patterns. Separate linear regression models with dietary pattern scores as the dependent variable and continuous sleep measures as independent variables were used to evaluate associations between sleep and diet, adjusting for sex, age, parent education level, and sleep hygiene.

RESULTS

Three dietary patterns were identified: Vegetables, Healthy Proteins, and Sides; Breads and Spreads; and Processed and Fried. Longer average weekend sleep duration and a greater difference in weekend-to-weekday sleep duration was related to lower Vegetables, Healthy Proteins, and Sides pattern scores. Later sleep midpoint during weekdays was related to lower Vegetables, Healthy Proteins, and Sides pattern scores, whereas later sleep midpoint on the weekend was associated with higher Processed and Fried pattern scores. Similarly, a larger weekend-weekday midpoint difference was associated with higher Processed and Fried pattern scores.

CONCLUSIONS

Later sleep timing and differences in sleep duration and timing from weekends to weekdays were related to less-optimal dietary pattern scores in young children.

Potential circadian and circannual rhythm contributions to the obesity epidemic in elementary school age children

Children gain weight at an accelerated rate during summer, contributing to increases in the prevalence of overweight and obesity in elementary-school children (i.e., approximately 5 to 11 years old in the US). Int J Behav Nutr Phys Act 14:100, 2017 explained these changes with the "Structured Days Hypothesis" suggesting that environmental changes in structure between the school year and the summer months result in behavioral changes that ultimately lead to accelerated weight gain. The present article explores an alternative explanation, the circadian clock, including the effects of circannual changes and social demands (i.e., social timing resulting from societal demands such as school or work schedules), and implications for seasonal patterns of weight gain. We provide a model for understanding the role circadian and circannual rhythms may play in the development of child obesity, a framework for examining the intersection of behavioral and biological causes of obesity, and encouragement for future research into bio-behavioral causes of obesity in children.

Family contexts and sleep during adolescence

Sleep deprivation among adolescents has received much attention from health researchers and policymakers. Recent research indicates that variation in sleep duration from night to night is associated with multiple health outcomes. While there is evidence that sleep deprivation is socially patterned, we know little about how social contexts are associated with nightly sleep variation during adolescence (a life course stage when nightly sleep variation is particularly high). Given the importance of family environments for influencing adolescents’ sleep patterns, we hypothesized that disadvantaged family contexts would be associated with higher intra-individual variation (IIV) in nightly sleep duration, in addition to lower average nightly sleep duration. We tested these hypotheses in a diverse, population-based sample of 11–17 year-olds (N = 1095) from the Adolescent Health and Development in Context Study. Using survey and ecological momentary assessment data and a novel form of multi-level regression modeling (location-scale mixed modeling), we found that adolescents living in unmarried-parent, low SES, economically insecure, and high caregiver stress families had higher IIV in sleep than adolescents in families with more resources and less caregiver stress. There were fewer family effects on average sleep duration. This suggests family social and economic contexts are associated with an under-researched aspect of adolescent sleep, nightly variation, and may contribute to adolescent sleep problems with implications for their health and health disparities.

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Consistency in nightly sleep duration is important for adolescent health.

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SES and family stress associated with variability in sleep duration in adolescents.

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Caregiver distress also associated with lower mean sleep duration among adolescents.

Sleep, Circadian Rhythms, and Risk Across Health Domains in Adolescents With an Evening Circadian Preference

Sleep and circadian rhythm changes during adolescence contribute to increased risk across emotional, behavioral, cognitive, social, and physical health domains. This study examines if sleep and dim light melatonin onset (DLMO) are related to greater risk in these 5 health domains. Participants were 163 (93 female, age = 14.7 years) adolescents with an evening circadian preference from a study funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development. Sleep and circadian measures included weekday total sleep time (TST), bedtime, and shut-eye time assessed via sleep diary, the Children's Morningness-Eveningness Preferences scale, and DLMO. Health domains included self-reported emotional, cognitive, behavioral, social, and physical health. Later DLMO was significantly associated with shorter weekday TST, later weekday bedtime, and later weekday shut-eye time, as well as lower risk in the behavioral domain. At the trend level, later DLMO was related to fewer physical health problems. Earlier DLMO combined with a later bedtime, later shut-eye time, or shorter TST predicted greater risk in the cognitive domain. Later DLMO and shorter TST or a later bedtime predicted worse physical health. DLMO timing was not related to the emotional or social domain. There is evidence that a discrepancy between sleep behaviors and the endogenous circadian rhythm may be related to risk in the cognitive domain for adolescents with an evening circadian preference. Preliminary evidence also indicated that a delayed DLMO and shorter TST or a later bedtime may be related to vulnerability to physical health risk.

Sleep timing is associated with self-reported dietary patterns in 9- to 15-year-olds

OBJECTIVE

To examine sleep timing differences in self-reported dietary patterns of children and adolescents.

DESIGN

Cross-sectional.

PARTICIPANTS

Students aged 9-15 years (n=119, 11.7±1.3 years, 76% female) attending a summer program for the gifted. The upper and lower quartiles of reported midsleep time (weighted weekday-weekend average) were used to identify early (n=28) and late (n=27) sleep timing groups.

METHODS

Sleep patterns were assessed via self-report. Participants also rated their likelihood to consume 9 different categories of food and drinks on a 5-point scale ranging from "no likelihood" to "high likelihood." Foods were grouped as follows: (1) sugary and caffeinated beverages; (2) high-energy-dense, nutrient-poor foods (ie, sugary, salty, fatty foods); and (3) low-energy-dense, nutrient-rich foods (ie, vegetables, proteins, carbohydrates, fruits).

RESULTS

Midsleep time was 02:11±00:25 for the early and 06:14±01:00 for the late sleep timing groups. Participants reporting later sleep timing were more likely to consume sugary/caffeinated beverages and high-energy-dense, nutrient-poor foods throughout the day compared with their early sleep timing peers. The late vs the early sleep timing group also had a higher likelihood of overall consumption of foods and drinks from all categories into the evening and nighttime hours.

CONCLUSION

Our findings indicate that children and adolescents who exhibit late sleep timing are more likely to make poorer dietary choices, which may have important implications for understanding pathways to adiposity and obesity risk during this sensitive period of development.