The association between sleep health and weight change during a 12-month behavioral weight loss intervention

Impact of baseline adipose tissue characteristics on change in adipose tissue volume during a low calorie diet in people with obesity-results from the LION study

BACKGROUND/OBJECTIVES

Weight loss outcomes vary individually. Magnetic resonance imaging (MRI)-based evaluation of adipose tissue (AT) might help to identify AT characteristics that predict AT loss. This study aimed to assess the impact of an 8-week low-calorie diet (LCD) on different AT depots and to identify predictors of short-term AT loss using MRI in adults with obesity.

METHODS

Eighty-one adults with obesity (mean BMI 34.08 ± 2.75 kg/m², mean age 46.3 ± 10.97 years, 49 females) prospectively underwent baseline MRI (liver dome to femoral head) and anthropometric measurements (BMI, waist-to-hip-ratio, body fat), followed by a post-LCD-examination. Visceral and subcutaneous AT (VAT and SAT) volumes and AT fat fraction were extracted from the MRI data. Apparent lipid volumes based on MRI were calculated as approximation for the lipid contained in the AT. SAT and VAT volumes were subdivided into equidistant thirds along the craniocaudal axis and normalized by length of the segmentation. T-tests compared baseline and follow-up measurements and sex differences. Effect sizes on subdivided AT volumes were compared. Spearman Rank correlation explored associations between baseline parameters and AT loss. Multiple regression analysis identified baseline predictors for AT loss.

RESULTS

Following the LCD, participants exhibited significant weight loss (11.61 ± 3.07 kg, p < 0.01) and reductions in all MRI-based AT parameters (p < 0.01). Absolute SAT loss exceeded VAT loss, while relative apparent lipid loss was higher in VAT (both p < 0.01). The lower abdominopelvic third showed the most significant SAT and VAT reduction. The predictor of most AT and apparent lipid losses was the normalized baseline SAT volume in the lower abdominopelvic third, with smaller volumes favoring greater AT loss (p < 0.01 for SAT and VAT loss and SAT apparent lipid volume loss).

CONCLUSIONS

The LCD primarily reduces lower abdominopelvic SAT and VAT. Furthermore, lower abdominopelvic SAT volume was detected as a potential predictor for short-term AT loss in persons with obesity.

An adapted transdiagnostic sleep and circadian intervention for adults with excess weight and suboptimal sleep health: pilot study results

Study Objectives

This single-arm, mixed-methods, pilot study examined the feasibility and preliminary efficacy of an adapted version of the transdiagnostic intervention for sleep and circadian dysfunction (TranS-C) on multidimensional sleep health (MDSH) in a sample of adults with excess weight and suboptimal sleep health.

Methods

Participants received up to eight, weekly, remotely delivered, tailored TranS-C sessions. At pre- and post-intervention, the Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale, and 7 days of Fitbit data were used to evaluate changes in sleep dimensions (regularity, alertness, timing, satisfaction, duration, and efficiency) and the composite MDSH score. Study feasibility examined recruitment, data collection, and intervention engagement (completion of core TranS-C sessions). Acceptability of the intervention was assessed with semi-structured interviews, which were analyzed using thematic analysis.

Results

From 85 referrals, 11 individuals were eligible, and 10 completed the study. All intervention participants completed the measures needed to calculate their composite MDSH score and completed the core intervention sessions. Themes from interviews support the intervention's remote delivery approach, applicability of the information provided, and impact on self-reported health. The intervention resulted in a large improvement in the mean composite MDSH score (Cohen's d = 1.17). Small-to-large effects were also observed for individual sleep health dimensions except for timing.

Conclusions

Adapted TranS-C is acceptable for adults with excess weight and suboptimal sleep health and may be effective at improving short-term MDSH. With changes to recruitment methods, a larger study is feasible. Limitations include the small sample size and the lack of a control condition.

Healthcare Service Providers' Perspectives on Sociocultural Aspects Affecting Weight Management Activities Amongst People with Obesity in Taiwan-A Qualitative Study

The prevalence of obesity and morbid obesity in Taiwan has risen sharply in recent decades, as in other parts of the world, necessitating urgent action to prevent and curb its detrimental effects. Asian populations are susceptible to the repercussions of obesity at a lower body weight. A higher BMI is associated with more frequent outpatient visits, in-hospital admissions, higher medical costs, and a lower quality of life. However, effective weight management approaches are unlikely to be maintained in the long term without assimilation into daily lifestyle practices. This qualitative study, based on semi-structured interviews with 14 doctors, dieticians, and nurses who work to control the weight of people with obesity, explored and identified multilevel barriers in the context of daily life to improve the efficacy and execution of weight management strategies. They considered diets, physical activity, and sleep as key weight management activities. The cultural and psychosocial aspects of daily life were observed to have an impact upon weight management, particularly family conflicts due to cultural dynamics and socially and culturally reinforced food practices. To improve population weight, less-recognised aspects need to be addressed alongside the inclusion of mental health specialists in weight management protocols and policy interventions to minimise obesogenic practices and create environments conducive to weight management.

Sleep Characteristics are Associated with Risk of Treated Diabetes Among Postmenopausal Women

OBJECTIVE

The purpose of this study was to determine whether sleep characteristics are associated with incidence of treated diabetes in postmenopausal individuals.

METHODS

Postmenopausal participants ages 50-79 years reported sleep duration, sleep-disordered breathing, or insomnia at baseline and again in a subsample 3 years later. The primary outcome was self-reported new diagnosis of diabetes treated with oral drugs or insulin at any time after baseline. Multivariable Cox proportional hazards models were used.

RESULTS

In 135,964 participants followed for 18.1 (± 6.3) years, there was a nonlinear association between sleep duration and risk of treated diabetes. Participants sleeping ≤5 hours at baseline had a 21% increased risk of diabetes compared with those sleeping 7 hours (adjusted hazard ratio [aHR] 1.21; 95% confidence interval [CI], 1.00-1.47). Those who slept for ≥9 hours had a nonsignificant 6% increased risk of diabetes compared with those sleeping 7 hours (aHR 1.06; 95% CI, 0.97-1.16). Participants whose sleep duration had decreased at 3 years had a 9% (aHR 1.09; 95% CI, 1.02-1.16) higher risk of diabetes than participants with unchanged sleep duration. Participants who reported increased sleep duration at 3 years had a risk of diabetes (HR 1.01; 95% CI, 0.95-1.08) similar to those with no sleep duration change. Participants at high risk of sleep-disordered breathing at baseline had a 31% higher risk of diabetes than those without (aHR 1.31; 95% CI, 1.26-1.37). No association was found between self-reported insomnia score and diabetes risk.

CONCLUSIONS

Sleep-disordered breathing and short or long sleep duration were associated with higher diabetes risk in a postmenopausal population.

Sleep extension and cardiometabolic health: what it is, possible mechanisms and real-world applications

Short sleep duration is associated with heightened cardiometabolic disease risk and has reached epidemic proportions among children, adolescents and adults. Potential mechanisms underlying this association are complex and multifaceted, including disturbances in circadian timing, food intake and appetitive hormones, brain regions linked to control of hedonic eating, physical activity, an altered microbiome and impaired insulin sensitivity. Sleep extension, or increasing total sleep duration, is an emerging and ecologically relevant intervention with significant potential to advance our understanding of the mechanisms underlying the association between short sleep duration and the risk of cardiometabolic disease. If effective, sleep extension interventions have potential to improve cardiometabolic health across the lifespan. Existing data show that sleep extension is feasible and might have potential cardiometabolic health benefits, although there are limitations that the field must overcome. Notably, most existing studies are short term (2-8 weeks), use different sleep extension strategies, analyse a wide array of cardiometabolic health outcomes in different populations and, frequently, lack adequate statistical power, thus limiting robust scientific conclusions. Overcoming these limitations will require fully powered, randomized studies conducted in people with habitual short sleep duration and existing cardiometabolic risk factors. Additionally, randomized controlled trials comparing different sleep extension strategies are essential to determine the most effective interventions. Ongoing and future research should focus on elucidating the potential cardiometabolic health benefits of sleep extension. Such studies have high potential to generate crucial knowledge with potential to improve health and quality of life for those struggling with short sleep duration.

Sleep characteristics modify the associations of physical activity during pregnancy and gestational weight gain

OBJECTIVE

Excessive gestational weight gain (eGWG) is associated with adverse long-term maternal outcomes. Most lifestyle interventions that incorporate physical activity have been ineffective at reducing eGWG. The purpose of this study was to determine if sleep modified the relationships between physical activity change from the 2nd to 3rd trimester and the odds of excessive gestational weight gain (eGWG).

METHODS

This was a secondary data analysis of a prospective cohort study of pregnant birthing people with overweight or obesity (n = 105). We estimated physical activity energy expenditure (PAEE) in the 2nd and 3rd trimesters of pregnancy and sleep characteristics (i.e., sleep quality, daytime dysfunction, sleep efficiency, sleep duration) in the 2nd trimester of pregnancy with validated measures. We used regression models with sleep and PAEE change (increase/stable vs. decrease) interaction terms to examine the impact of sleep on PAEE change and eGWG.

RESULTS

Mean GWG was 37.02 ± 16.76 lbs. and 80% of participants experienced eGWG. Eighteen percent of participants increased their PAEE from the 2nd to the 3rd trimester. Increasing (vs. decreasing) PAEE was associated with lower log-odds of eGWG only among participants that slept at least 8 h/night (p = 0.06), had at least 85% sleep efficiency (p = 0.03), or reported less daytime dysfunction (p = 0.08). Sleep quality did not moderate the association between PAEE change and eGWG.

CONCLUSIONS

Weight management interventions in pregnancy should consider screening for and addressing poor sleep in the second trimester.

The association of multidimensional sleep health with adiposity in heart failure with preserved ejection fraction

BACKGROUND

There are bi-directional relationships between sleep disturbances and obesity, both of which are prevalent in patients with heart failure with preserved ejection fraction (HFpEF). However, little is known about the sleep-obesity association in HFpEF.

OBJECTIVES

To determine associations of multidimensional sleep health, night movement, sleep fragmentation, and sleep-disordered breathing (SDB) risk with overall and regional adiposity in HFpEF patients.

METHODS

Men and women with HFpEF (n = 49) were assessed via 14-day actigraphy, Pittsburgh Sleep Quality Index, and Epworth Sleepiness Scale to derive multidimensional sleep health. SDB risk was assessed via Berlin Questionnaire. Body composition was measured using anthropometry; MRI quantification of epicardial, abdominal, liver, and thigh adipose tissue was performed in a subsample (n = 22). Spearman correlation (rs) and linear regression analyses (β coefficient) were used to estimate bivariate and age-adjusted associations.

RESULTS

Multidimensional sleep health was inversely associated with BMI (rs = -0.50, p < .001; unadjusted: β = -4.00, 95%CI: -5.87, -2.13; age-adjusted: β = -2.48, 95%CI: -4.65, -0.30), thigh subcutaneous adipose tissue (rs = -0.50, p = .018; unadjusted: β = -36.95, 95%CI: -67.31, -6.59), and thigh intermuscular fat (age-adjusted: β = -0.24, 95%CI: -0.48, -0.01). Night movement and sleep fragmentation were associated with greater intermuscular thigh and lower liver fat. High SDB risk was associated with a higher visceral-to-subcutaneous ratio of abdominal adiposity and lower thigh adiposity.

CONCLUSIONS

Adverse multidimensional sleep health is associated with higher adiposity measures in HFpEF patients. Further studies are needed to determine whether intervening on sleep could ameliorate excess adiposity or whether weight loss could improve sleep quality in HFpEF.

Effectiveness of Non-Contact Dietary Coaching in Adults with Diabetes or Prediabetes Using a Continuous Glucose Monitoring Device: A Randomized Controlled Trial

We aimed to evaluate the effectiveness of dietary coaching and continuous glucose monitoring (CGM) in patients with diabetes or prediabetes to improve their behavioral skills and health outcomes. A randomized controlled study with pre- and post-testing was conducted. Data were collected between November 2020 and April 2021. Forty-five patients with diabetes or prediabetes who used a CGM device were enrolled and analyzed. Dietary education, individual coaching and group coaching were provided to participants in the experimental group for 4 weeks. After the intervention, the thigh circumference in men significantly differed between the two groups (z = -2.02, p = 0.044). For women, participants in the experimental group showed greater improvement in eating self-efficacy compared with those in the control group (z = -2.66, p = 0.008). Insomnia was negatively related to the change in eating self-efficacy (r = -0.35, p = 0.018) and increase in thigh circumference (r = -0.35, p = 0.017). Even if used within a short intervention period, non-contact dietary coaching programs can help enhance behavioral skills, such as eating self-efficacy and health outcomes, such as thigh circumference. Moreover, the changed variables can indirectly improve other health outcomes in patients with diabetes or prediabetes.

Associations between sleep variability and cardiometabolic health: A systematic review

This review explored the associations between sleep variability and cardiometabolic health. It was performed following PRISMA guidelines. We identified 63 studies. Forty-one studies examined the association between sleep variability and body composition, with 29 examined body mass index (BMI). Thirteen studies used social jet lag (SJL), n = 30,519, with nine reporting a null association. Eight studies used variability in sleep duration (n = 33,029), with five reporting a correlation with BMI. Fourteen studies (n = 133,403) focused on overweight/obesity; significant associations with sleep variability were found in 11 (n = 120,168). Sleep variability was associated with weight gain (seven studies; n = 79,522). Twenty-three studies examined glucose outcomes. The association with hemoglobin A1c (16 studies, n = 11,755) differed depending on populations, while associations with diabetes or glucose were mixed, and none were seen with insulin resistance (five studies; n = 6416). Sixteen studies examined cardiovascular-related outcomes, with inconsistent results. Overall significant associations were found in five studies focusing on metabolic syndrome (n = 7413). In summary, sleep variability was likely associated with obesity, weight gain, and metabolic syndrome. It might be associated with hemoglobin A1c in people with type 1 diabetes. The associations with other outcomes were mixed. This review highlighted the possible association between sleep variability and cardiometabolic health.

The Impact of COVID-19 on the Health-Related Behaviours, Mental Well-Being, and Academic Engagement of a Cohort of Undergraduate Students in an Irish University Setting

Given the well-established impact of COVID-19 on university students' health and lifestyle parameters, the current study sought to investigate these impacts within an Irish university setting. A cross-sectional design was employed, with a 68-item questionnaire instrument disseminated to all Year 2 undergraduate students in the host institution (N = 2752), yielding a 9.7% response rate (n = 266). This questionnaire elicited students' self-reported changes to health-related behaviours, mental well-being and academic engagement across 4 defined time-points: (T0: prior to COVID-19, T1: initial onset of COVID-19, T2: during COVID-19, and T3: time of data collection). Many items were adapted from previous Irish research and additional validated scales included the Alcohol Use Disorders Identification Test (AUDIT-C) and the World Health Organisation's Well-being scale (WHO-5). Key findings revealed that at T1, substantially more males reported 'good/very good' general health than females (76.3% vs. 70.8%), while physical activity patterns followed a similar trend at both T0 (80% vs. 66.1%) and T1 (66.7% vs. 61%). A total of 78.4% of participants reported a body mass gain from T0 to T3, thus reflecting the reduced physical activity levels and compromised nutritional patterns across this period. Worryingly, AUDIT-C scale data revealed hazardous drinking habits were evident in both males and females, while fruit and vegetable intake, physical activity levels, and mental well-being among this cohort remained notably sub-optimal. Ratings of positive academic engagement also decreased substantially between T0 (90.3%) and T3 (30.4%). These findings substantiate the rationale for tailored health promotion interventions in university settings to support students' transition back to traditional programme delivery and, of equal importance, to improve general health and well-being post-COVID-19 within this cohort.

Healthy Sleep Every Day Keeps the Doctor Away

When one considers the big picture of their health, sufficient sleep may often go overlooked as a keystone element in this picture. Insufficient sleep in either quality or duration is a growing problem for our modern society. It is essential to look at what this means for our health because insufficient sleep increases our risks of innumerable lifechanging diseases. Beyond increasing the risk of developing these diseases, it also makes the symptoms and pathogenesis of many diseases worse. Additionally, consistent quality sleep can not only improve our physical health but has also been shown to improve mental health and overall quality of life. Substandard sleep health could be a root cause for numerous issues individuals may be facing in their lives. It is essential that physicians take the time to learn about how to educate their patients on sleep health and try to work with them on an individual level to help motivate lifestyle changes. Facilitating access to sleep education for their patients is one way in which physicians can help provide patients with the tools to improve their sleep health. Throughout this paper, we will review the mechanisms behind the relationship between insufficient sleep health and chronic disease and what the science says about how inadequate sleep health negatively impacts the overall health and the quality of our lives. We will also explain the lifechanging effects of sufficient sleep and how we can help patients get there.

The emerging importance of tackling sleep-diet interactions in lifestyle interventions for weight management

Sleep habits are directly related to risk of obesity, and this relationship may be partly mediated through food choices and eating behaviour. Short sleep duration, impaired sleep quality and suboptimal sleep timing are all implicated in weight gain and adverse cardiometabolic health, at least partly mediated through their associations with diet quality. Short-term sleep restriction leads to increased energy intake, and habitually short sleepers report dietary intakes that indicate a less healthy diet compared with adequate sleepers. Evidence is emerging that sleep extension interventions in short sleepers may reduce intake of sugars and overall energy intake. Poor sleep quality, night shift work patterns and social jetlag are also associated with lower diet quality and consumption of energy-dense foods. Incorporating sleep advice into weight management interventions may be more effective than energy-restricted diets and exercise advice alone. However, there are a lack of intervention studies that aim to lengthen sleep, improve sleep quality or adjust irregular sleep timing to investigate the impact on dietary intakes and eating behaviour in participants aiming to lose weight or maintain weight loss. Finally, future research should take account of individual characteristics such as age, sex, life stage and changing working practices when designing combined lifestyle interventions including sleep behaviour change for health and well-being.

Effect of sleep on weight loss and adherence to diet and physical activity recommendations during an 18-month behavioral weight loss intervention

BACKGROUND/OBJECTIVES

To examine the association between indices of sleep quantity and quality with dietary adherence, physical activity adherence, and weight loss during a behavioral weight loss intervention.

METHODS

Adults (n = 156) with overweight and obesity (40 ± 9 years, 84% female, BMI: 34.4 ± 4.2 kg/m²) participated in an 18-month behavioral weight loss intervention which prescribed a reduced calorie diet (1200-1800 kcal/d) and increased physical activity (300 min/wk). Body weight, indices of sleep (SenseWear armband; SWA), energy intake (EI, 3-day food records), and moderate-to-vigorous physical activity (SWA) were measured at baseline, 6, 12, and 18 months. Linear mixed effects models examined the association between sleep and weight change over time. Additional models were adjusted for covariates including age, BMI, sex, race, ethnicity, study completion, randomization, EI, and physical activity. Secondary analyses examined the association between sleep and adherence to diet and physical activity recommendations.

RESULTS

Mean weight loss was 7.7 ± 5.4, 8.4 ± 7.9, and 7.1 ± 9.0 kg at 6, 12, and 18 months, respectively. Lower sleep efficiency, higher wake after sleep onset (WASO), more awakenings, and higher sleep onset latency (SOL) were significantly associated with attenuated weight loss (p < 0.05). Lower sleep efficiency, more awakenings, and higher SOL remained significantly associated with blunted weight loss after adjustment for covariates (p < 0.05). Later waketime, longer time in bed, longer sleep duration, higher WASO, more awakenings, and higher SOL were associated with lower odds of achieving ≥300 min/wk of moderate-to-vigorous physical activity, adjusted for covariates (FDR p < 0.05).

CONCLUSIONS

Future studies should evaluate whether incorporating strategies to improve sleep health within a behavioral weight loss intervention leads to improved adherence to diet and physical activity recommendations and enhanced weight loss.

CLINICAL TRIALS IDENTIFIER

NCT01985568.

Effect of Sleep Extension on Objectively Assessed Energy Intake Among Adults With Overweight in Real-life Settings: A Randomized Clinical Trial

IMPORTANCE

Short sleep duration has been recognized as a risk factor for obesity. Whether extending sleep duration may mitigate this risk remains unknown.

OBJECTIVE

To determine the effects of a sleep extension intervention on objectively assessed energy intake, energy expenditure, and body weight in real-life settings among adults with overweight who habitually curtailed their sleep duration.

DESIGN, SETTING, AND PARTICIPANTS

This single-center, randomized clinical trial was conducted from November 1, 2014, to October 30, 2020. Participants were adults aged 21 to 40 years with a body mass index (calculated as weight in kilograms divided by height in meters squared) between 25.0 and 29.9 and had habitual sleep duration of less than 6.5 hours per night. Data were analyzed according to the intention-to-treat principle.

INTERVENTIONS

After a 2-week habitual sleep period at baseline, participants were randomized to either an individualized sleep hygiene counseling session that was intended to extend their bedtime to 8.5 hours (sleep extension group) or to continue their habitual sleep (control group). All participants were instructed to continue daily routine activities at home without any prescribed diet or physical activity.

MAIN OUTCOMES AND MEASURES

The primary outcome was change in energy intake from baseline, which was objectively assessed as the sum of total energy expenditure and change in body energy stores. Total energy expenditure was measured by the doubly labeled water method. Change in body energy stores was computed using regression of daily home weights and body composition changes from dual-energy x-ray absorptiometry. Sleep duration was monitored by actigraphy. Changes from baseline were compared between the 2 groups using intention-to-treat analysis.

RESULTS

Data from 80 randomized participants (mean [SD] age, 29.8 [5.1] years; 41 men [51.3%]) were analyzed. Sleep duration was increased by approximately 1.2 hours per night (95% CI, 1.0 to 1.4 hours; P < .001) in the sleep extension group vs the control group. The sleep extension group had a significant decrease in energy intake compared with the control group (-270 kcal/d; 95% CI, -393 to -147 kcal/d; P < .001). The change in sleep duration was inversely correlated with the change in energy intake (r = -0.41; 95% CI, -0.59 to -0.20; P < .001). No significant treatment effect in total energy expenditure was found, resulting in weight reduction in the sleep extension group vs the control group.

CONCLUSIONS AND RELEVANCE

This trial found that sleep extension reduced energy intake and resulted in a negative energy balance in real-life settings among adults with overweight who habitually curtailed their sleep duration. Improving and maintaining healthy sleep duration over longer periods could be part of obesity prevention and weight loss programs.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02253368.

Examining the Role of Exercise Timing in Weight Management: A Review

Many adults cite exercise as a primary strategy for losing weight, yet exercise alone is modestly effective for weight loss and results in variable weight loss responses. It is possible that some of the variability in weight loss may be explained by the time of day that exercise is performed. Few studies have directly compared the effects of exercise performed at different times of the day (i. e., morning versus evening exercise). Results from these existing studies are mixed with some studies demonstrating superior weight and fat mass loss from morning exercise, while other studies have found that evening exercise may be better for weight management. Exercise timing may alter modifiable lifestyle behaviors involved in weight management, such as non-exercise physical activity, energy intake, and sleep. The purpose of this review is to summarize evidence for and against time-of-day dependent effects of exercise on weight management. Although limited, we also review studies that have examined the effect of exercise timing on other lifestyle behaviors linked to body weight regulation. While exercise at any time of day is beneficial for health, understanding whether there is an optimal time of day to exercise may advance personalized treatment paradigms for weight management.

Sleep Health Characteristics among Adults Who Attempted Weight Loss in the Past Year: NHANES 2017-2018

Background: The purpose of this study was to characterize sleep health in adults who attempted weight loss in the prior year. Methods: We analyzed data from the National Health and Nutrition Examination Survey 2017–2018 exam cycle. We included 4837 US adults who did (n = 1919) or did not (n = 2918) attempt weight loss in the past year. Participants self-reported their sleep regularity, satisfaction, sleepiness, timing, and duration, which we defined as “good” based on the prior literature. We characterized sleep health by weight loss attempts status, current BMI and weight change among participants who attempted weight loss. Results: On average, participants reported good sleep health in 3.21 ± 1.14 out of the five sleep domains. A total of 13% of participants had good sleep health in all five domains. The prevalence of sleep regularity (52%) was lowest, and the prevalence of infrequent sleepiness was highest (72%), relative to other sleep domains. In models adjusting for BMI, sleep health was similar in participants who did and did not attempt weight loss. Among adults who attempted weight loss, good sleep health was inversely associated with current BMI and self-reported weight change. Discussion: This study’s findings highlight the importance of considering sleep health when engaging with adults attempting weight loss.

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.

Predictors of weight loss in obese patients with obstructive sleep apnea

PURPOSE

Consistent predictors of weight loss outcomes with very low-energy diets (VLEDs) in obstructive sleep apnea (OSA) have not been identified. This study aimed to identify variables predictive of weight loss success in obese patients with OSA undertaking an intensive weight loss programme.

METHODS

We analysed biological, psychological, and behavioural variables as potential predictors of weight loss in obese patients with OSA after a 2-month VLED followed by one of two 10-month weight loss maintenance diets. Actigraphy, in-lab polysomnography, urinary catecholamines, and various psychological and behavioural variables were measured at baseline, 2, and 12 months. Spearman's correlations analysed baseline variables with 2-month weight loss, and 2-month variables with 2-12 month-weight change.

RESULTS

Forty-two patients completed the VLED and thirty-eight completed the maintenance diets. Actigraphy data revealed that late bedtime (r_s =  - 0.45, p =  < 0.01) was correlated with 2-month weight loss. The change in the time that participants got out of bed (rise-time) from baseline to two months was also correlated with 2-month weight loss (r_s = 0.36, p = 0.03). The Impact of Weight on Quality of Life-Lite questionnaire (IWQOL) Public Distress domain (r_s =  - 0.54, p =  < 0.01) and total (r_s =  - 0.38, p = 0.02) scores were correlated with weight loss maintenance from 2 to 12 months.

CONCLUSIONS

Results from this small patient sample reveal correlations between actigraphy characteristics and weight loss in obese patients with OSA. We suggest the IWQOL may also be a useful clinical tool to identify OSA patients at risk of weight regain after initial weight loss.

CLINICAL TRIAL REGISTRATION

This clinical trial was prospectively registered on 18/02/2013 with the Australia and New Zealand Clinical Trials Registry (ACTRN12613000191796).

PUBLIC REGISTRY TITLE

Sleep, Lifestyle, Energy, Eating, Exercise Program for the management of sleep apnea patients indicated for weight loss treatment: A randomised, controlled pilot study. URL: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=363680.