BackgroundThere is growing evidence that sleep duration and quality may be associated with cardiovascular harm and mortality.Methods and ResultsWe conducted a systematic review, meta‐analysis, and spline analysis of prospective cohort studies that evaluate the association between sleep duration and quality and cardiovascular outcomes. We searched MEDLINE and EMBASE for these studies and extracted data from identified studies. We utilized linear and nonlinear dose‐response meta‐analysis models and used DerSimonian–Laird random‐effects meta‐analysis models of risk ratios, with inverse variance weighting, and the I2 statistic to quantify heterogeneity. Seventy‐four studies including 3 340 684 participants with 242 240 deaths among 2 564 029 participants who reported death events were reviewed. Findings were broadly similar across both linear and nonlinear dose‐response models in 30 studies with >1 000 000 participants, and we report results from the linear model. Self‐reported duration of sleep >8 hours was associated with a moderate increased risk of all‐cause mortality, with risk ratio, 1.14 (1.05–1.25) for 9 hours, risk ratio, 1.30 (1.19–1.42) for 10 hours, and risk ratio, 1.47 (1.33–1.64) for 11 hours. No significant difference was identified for periods of self‐reported sleep <7 hours, whereas similar patterns were observed for stroke and cardiovascular disease mortality. Subjective poor sleep quality was associated with coronary heart disease (risk ratio, 1.44; 95% confidence interval, 1.09–1.90), but no difference in mortality and other outcomes.ConclusionsDivergence from the recommended 7 to 8 hours of sleep is associated with a higher risk of mortality and cardiovascular events. Longer duration of sleep may be more associated with adverse outcomes compared with shorter sleep durations.

Bariatric (weight loss) surgery is the gold standard treatment for severe obesity. Concern exists that patients are regaining weight in the longer term. Success and cost-effectiveness of surgery are threatened due to the re-emergence of related conditions such as diabetes. This exploratory qualitative study investigates patients' expectations and experiences of weight regain (WR) 2 years or more after Roux-en-Y gastric bypass (RYGB). Ten participants (two men and eight women) who experienced WR were interviewed between 2 and 6 years following surgery. Findings highlight that participants reacted to initial weight loss as passive spectators and were unprepared for subsequent WR. Their tolerability of WR reduced as the amount of regain increased, suggesting a 'line of tolerance' for WR. WR was influenced by a new vulnerability arising from weight loss over time, and participants struggled to manage their own weight actively as surgical effects waned. They considered self-management skills, and carer and professional support to be limited at the time when WR was most likely to occur. Degrees of tolerability are noted in individuals regaining weight after RYGB. More studies are needed to further understand these problems. Pre- and post-operative support and teaching patients self-management skills may be helpful to minimize WR.

Night eating syndrome (NES) was first identified in 1955 by Stunkard, a psychiatrist specialising in eating disorders (ED). Over the last 20 years considerable progress has been made in defining NES as a significant clinical entity in its own right and it has now been accepted for inclusion in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) due for publication in 2013. NES is considered a dysfunction of circadian rhythm with a disassociation between eating and sleeping. Core criteria include a daily pattern of eating with a significantly increased intake in the evening and/or night time, as manifested by one or both of the following: at least 25% of food intake is consumed after the evening meal or at least two episodes of nocturnal eating per week. An important recent addition to core criteria includes the presence of significant distress and/or impairment in functioning. Stunkard's team recommend further investigation on the pathogenesis of NES, in particular its relationship with traumatic life events, psychiatric comorbidity, the age of onset of NES and course of NES over time. The relationship between NES and other ED also requires further clarification as night-eaters exhibit some features of other ED; previous guidance to separate NES from other ED may have hindered earlier characterisation of NES. Evidence from European and American studies suggests NES features strongly in populations with severe obesity. The complex interplay between depression, impaired sleep and obesity-related comorbidity in severely obese individuals makes understanding NES in this context even more difficult. This review examines evidence to date on the characterisation of NES and concludes by examining the applicability of current NES criteria to individuals with severe obesity.

Night eaters with severe obesity are more likely to be low in mood and unemployed compared with non-night eaters. Night eaters with severe obesity describe compulsive and uncontrolled eating. Research interest in night-eating syndrome (NES) has grown in recent years in line with increased rates of obesity. This study used a mixed-methods approach to investigate its characteristics in severe obesity. Eighty-one individuals (mean [standard deviation] age 44.6 [11.6] years, [body mass index] 50.0 [10.7] kg m(-2) ; 43% men) from a hospital-based UK obesity clinic were interviewed for NES based on 2003 criteria. Full and partial NES were combined into one night-eating behaviour (NEB) group (n = 31). Demographic and clinical characteristics were compared with those of non-NEB individuals (n = 50). NEB characteristics were also identified through exploratory thematic analysis of interview data. NEB individuals had lower mood (P = 0.01) and were less likely to be employed (P = 0.03). Differences in mean age and reported sleep duration were not significant. Thematic analysis of patient perceptions of NEB highlighted the potential heterogeneity of NEB development: NEB developed in childhood, adolescence and adulthood. Individuals reported long-standing and current sleep difficulties, negative affect and conflictful relationships. Night eating was solitary, compulsive and uncontrolled, and daytime eating patterns were chaotic. Accounts of awareness of night eating were conflicting. Severely obese night eaters are characterized by low mood and lack of employment. Further studies are required to explore behavioural and cognitive influences on night eating in severe obesity.

We report here for the first time that GIP infusion may impact on resting EE and subjective appetite sensations in normal weight healthy subjects and further studies with larger numbers of subjects are required to help define more conclusively the precise role of GIP in energy balance in humans.