Exploring the mediating role of energy balance-related behaviours in the association between sleep duration and obesity in European adults. The SPOTLIGHT project

Sleep, Health Outcomes and Body Weight (SHOW) study: a measurement burst design study on sleep and risk factors for obesity in black emerging adults in North Carolina, USA

INTRODUCTION

Black emerging adults (18-28 years) have the highest risk of short sleep duration and obesity. This increased risk may be partly explained by greater stress levels, which may result from race-related stress (racial discrimination and heightened race-related vigilance) or living in more disadvantaged home and neighbourhood environments. Insufficient sleep may also impact obesity risk via several weight-related mechanisms including energy balance, appetite and food reward, cortisol profiles and hydration status. This paper describes the rationale, design and methods for the Sleep, Health Outcomes and Body Weight (SHOW) study. This study aims to prospectively assess the effects of sleep, race-related stress and home/neighbourhood environments on weight-related mechanisms and obesity markers (body weight, waist circumference and fat mass) in 150 black emerging adults.

METHODS AND ANALYSIS

The SHOW study follows a measurement burst design that includes 3, 7-day data collection bursts (baseline, 6-month and 12-month follow-ups). Sleep is measured with three methods: sleep diary, actigraphy and polysomnography. Energy balance over 7 days is based on resting and postprandial energy expenditure measured via indirect calorimetry, physical activity via accelerometry and self-reported and ad libitum energy intake methods. Self-reported methods and blood biomarkers assess fasting and postprandial appetite profiles and a behavioural-choice task measures food reward. Cortisol awakening response and diurnal cortisol profiles over 3 days are assessed via saliva samples and chronic cortisol exposure via a hair sample. Hydration markers are assessed with 24-hour urine collection over 3 days and fasting blood biomarkers. Race-related stress is self-reported over 7 days. Home and neighbourhood environments (via the Windshield Survey) is observer assessed.

ETHICS AND DISSEMINATION

Ethics approval was granted by the University of North Carolina at Greensboro's Institutional Review Board. Study findings will be disseminated through peer-reviewed publications, presentations at scientific meetings and reports, briefs/infographics for lay and community audiences.

[Sleep duration, overweight and consumption of ultra-processed foods among adolescents]

The scope of this article is to analyze the relationship between insufficient sleep duration, overweight/obesity and the consumption of ultra-processed foods among adolescents aged 10 to 14 years. This is a cross-sectional study, with an evaluation of 1,384 adolescents from public schools in João Pessoa-PB, participating in the Longitudinal Study on Sedentary Behavior, Physical Activity, Diet and Adolescent Health (LONCAAFS). Sociodemographic variables, sleep duration, class shift, anthropometric nutritional status, sedentary behavior and food consumption were measured. Linear and logistic regression of the following were performed using Stata 13.0 Software: the prevalence of short sleep duration of 29.5% (<9h/night); a significant association between short sleep duration and excess weight only for adolescents <12 years old. With respect to the relationship between sleep duration and the consumption of ultra-processed foods, the longer the sleep duration, the lower the consumption of snacks by adolescents under 12 years old, with a positive association for ≥12 years old only with adjustment by the physical activity variable. There was no association with the "sugary drinks" and "cookies" groups for any of the age groups analyzed.

Sleep and lifestyle in young adult monozygotic twin pairs discordant for body mass index

OBJECTIVES

The causal nature of the sleep-obesity association is unclear. To control for potential confounding by genes and shared environment, we studied monozygotic twin pairs discordant for body mass index (BMI). First, we investigated sleep in relation to BMI. Second, we examined associations of objective and subjective sleep duration and sleep debt (objective or subjective sleep duration minus subjective sleep need) with eating behaviors and physical activity (PA).

DESIGN

Cross-sectional study.

SETTING

Finnish twins in everyday life circumstances.

PARTICIPANTS

Seventy-four healthy young adult monozygotic twin pairs, of whom 36 were BMI-discordant (∆BMI ≥ 3 kg/m²).

MEASUREMENTS

Clinical measurements estimated BMI and body composition. Sleep, eating, and PA behaviors were measured by self-report and actigraphy.

RESULTS

Compared to co-twins with lower BMI, co-twins with higher BMI reported shorter sleep (P = .043), more snoring (P = .0093), and greater tiredness (P = .0013) and trended toward eveningness (P = .036). Actigraphy-measured sleep duration correlated highly within BMI-discordant twin pairs (r = 0.63, P = .004). Subjective sleep debt was consistently positively associated with disinhibited eating and binge eating, but not with BMI. Subjective and objective sleep debt had negative correlations with moderate-to-vigorous PA.

CONCLUSIONS

Twins with higher BMI showed less favorable sleep characteristics than their co-twins with lower BMI. Subjective sleep debt is a potential target for intervention to reduce eating and PA behaviors that promote weight gain. Experimental studies could elucidate mechanisms underlying tiredness in individuals with higher BMI and investigate causal relationships between sleep debt, BMI, and lifestyle.

Direct and indirect effects of poor sleep quality on BMI and waist circumference in a female population-based study in Southern Brazil

OBJECTIVE

This study aimed to investigate the direct and indirect effects of poor sleep quality on BMI and waist circumference (WC), considering behavioural factors as intermediate variables.

DESIGN

A population-based cross-sectional study design was adopted. Data were collected between February and October 2015. Poor sleep quality was assessed using the Brazilian version of the Pittsburgh Sleep Quality Index (PSQI-BR). Weight, height (used to calculate BMI) and WC were measured using standard protocols. Physical activity, sedentary behaviour and fast food consumption were considered intermediate variables. Non-standardised effects were estimated by path analysis with bootstrapped CI.

SETTING

Urban region of the city of São Leopoldo, southern Brazil.

PARTICIPANTS

Representative sample of 1117 women aged between 20 and 69 years.

RESULTS

Poor sleep quality (higher PSQI-BR scores) was significantly associated with low physical activity levels (β = -0·05; 95 % CI -0·09, -0·01). High physical activity levels were associated with lower BMI (β = -0·21; 95 % CI -0·37, -0·07) and WC (β = -0·64; 95 % CI -1·00, -0·30). There was a non-significant direct effect of poor sleep quality on BMI and WC. However, low physical activity showed a significant indirect effect on the association between poor sleep quality and increased WC (β = 0·03; 95 % CI 0·01, 0·07).

CONCLUSIONS

The results indicate that the association between sleep quality and WC is mediated by physical activity. This finding can assist in the development of strategies to prevent and reduce abdominal obesity in adult women.

The effect of a community-based e-health program to promote the role of physical activity among healthy adults in Hungary

Background

Physically active lifestyle can prolong the years spent without chronic diseases and is strongly associated with good mental and physical health. The goal of the study was to examine the physical activity patterns of the healthy adults and the effectiveness of a community-based e-health program.

Methods

The study sample comprised of 633 participants. Analyses were based on the E-Harmony health program that was conducted in Hungary in 2014–2015. The longitudinal study measured the physical activity patterns of the healthy adult population, and a 12-month community-based internet and media program was evaluated for the target group to improve the physical activity level and related knowledge. We examined the effectiveness of the program by the International Physical Activity Questionnaire – Hungarian validated long version adjusting for socio-demographic parameters, also across multivariate linear regression analysis using SPSS 24.0 software. Confidence interval of 95% was used and the level of significance was p < 0.05.

Results

The total physical activity of the study sample was 5129.9 (SD = 4488.1) MET min/week. Male participants scored higher in total activity but the results showed no statistical significance. Our participants were sitting 2211.6 (SD = 1592.8) min /week on average (daily average was 315.9 (SD = 227.6) minutes); the results showed no statistically significant difference by gender. We found weak but significant relationship between the active lifestyle and anthropometric data, especially according to leisure time activities and sedentary behaviour (p < 0.001). Based on the multivariate linear regression models the socio-demographic parameters significantly affected the physical activity level of participants. After the 12-month community-based e-health program, 10.34% changes occurred in the total physical activity level (p < 0.001).

Conclusions

To our knowledge, ours was the first community-based e-health program in Hungary to improve the physical activity level of the healthy adult population. Based on our results this web-based e-health program can be an adequate tool to promote healthy lifestyle. The study could provide appropriate information for the further health interventions and policy making. Further research is necessary to determine the special risk groups and to develop an applicable e-health program for such specific subgroups.

Sleep, Diet, and Cardiometabolic Health Investigations: a Systematic Review of Analytic Strategies

PURPOSE OF REVIEW

Poor sleep is a risk factor for cardiometabolic morbidity. The relationship of sleep and cardiometabolic health could be confounded, mediated, or modified by diet, yet the incorporation of diet in sleep-cardiometabolic health studies is inconsistent. This rapid systematic literature review evaluates the conceptualization of diet as a confounder, mediator, or effect modifier within sleep-cardiometabolic health investigations, and the statistical approaches utilized.

RECENT FINDINGS

Of 4692 studies identified, 60 were retained (28 adult, 32 pediatric). Most studies included diet patterns, quality, or energy intake as confounders, while a few examined these dietary variables as mediators or effect modifiers. There was some evidence, mostly in pediatric studies, that inclusion of diet altered sleep-cardiometabolic health associations. Diet plays a diverse role within sleep-cardiometabolic health associations. Investigators should carefully consider the conceptualization of diet variables in these relationships and utilize contemporary statistical approaches when applicable.

Bridging the Reciprocal Gap between Sleep and Fruit and Vegetable Consumption: A Review of the Evidence, Potential Mechanisms, Implications, and Directions for Future Work

A substantial burden of disease and mortality globally is attributable to both sleep disruption and low intakes of fruit and vegetable (FV) and there is increasing mechanistic and epidemiological evidence to support a reciprocal relationship between the two. This review provides an overview of experimental and observational studies assessing the relations between sleep and FV consumption from 52 human adult studies. Experimental studies are currently limited and show inconsistent results. Observational studies support a non-linear association with adults sleeping the recommended 7–9 hours/day having the highest intakes of FV. The potential mechanisms linking sleep and FV consumption are highlighted. Disrupted sleep influences FV consumption through homeostatic and non-homeostatic mechanisms. Conversely, FV consumption may influence sleep through polyphenol content via several potential pathways. Few human experimental studies have examined the effects of FV items and their polyphenols on sleep and there is a need for more studies to address this. An appreciation of the relationship between sleep and FV consumption may help optimize sleep and FV consumption and may reduce the burden of chronic diseases. This review provides implications for public health and directions for future work.

Are Older Adults without a Healthy Diet Less Physically Active and More Sedentary?

Few studies on older populations consider several energy balance-related behaviors together. This cross-sectional study compared subjectively and objectively measured physical activity (PA) and sedentary behavior (SB) patterns between older adults with and without a healthy diet. We recruited 127 community-dwelling older Taiwanese adults (69.9 ± 5.0 years); data were collected during April and September 2018. Objectively measured total PA, moderate-to-vigorous PA, light PA, step count, total sedentary time, duration of sedentary bouts, number of sedentary bouts, and number of sedentary breaks were assessed using activity monitors. Subjectively measured PA and SB were measured using the International Physical Activity Questionnaire and Sedentary Behavior Questionnaire for Older Adults. Chi-square tests and independent sample t-tests were performed. For subjective measures, older adults without a healthy diet spent significantly less total leisure time on PA and more leisure sitting time than those with a healthy diet. For objective measures, older adults without a healthy diet spent less time on light PA and had a higher total sedentary time, duration of sedentary bouts, times of sedentary bouts, and times of sedentary breaks than those with a healthy diet. Regardless of the use of objective or subjective measurements, older adults without a healthy diet engaged in a more inactive and sedentary lifestyle. These findings have implications for health promotion practitioners in designing tailored interventions.

Sleep and obesity: the mediating role of health behaviors among African Americans

OBJECTIVES

To examine the role of health behaviors (eg, physical activity, sedentary behaviors, and diet) in the relationship between sleep (ie, duration and quality) and BMI among African American adults.

DESIGN

A cross-sectional self-report questionnaire included questions related to health and health-related behaviors.

SETTING

This study was based on data from the CHURCH study, which aimed to address cancer health disparities among church-going African Americans in Houston, TX.

PARTICIPANTS

African American adults were recruited from three large community churches. The sample included a total of 1837 participants (75.2% female; mean age 48.2 ± 13.7y; mean BMI 32.0 ± 7.5 kg/m²).

MEASUREMENTS

Linear regression models and path analyses controlling for demographic characteristics and depression estimated the associations between sleep and BMI as well as the mediating roles of health behaviors.

RESULTS

The average self-reported sleep duration was 6.2 ± 1.5 h/night with 61%, 35.8%, and 1.6% reporting short (≤6 h/night), normal (7-9 h/night), and long sleep (≥10 h/night), respectively. Short sleep was related to greater BMI (b = 1.37, SE = 0.38, P = .01), and the relationship was mediated by sedentary behaviors (est. = 0.08, SE = 0.04, 95% CI: 0.02, 0.17).

CONCLUSIONS

Short sleep and poor quality sleep was related to poor diet and physical activity-related health behaviors, and BMI. The link between sleep and obesity is, in part, due to energy imbalance from increased sedentary behavior.