Sleep, circadian rhythm and body weight: parallel developments

Abstract

Circadian alignment is crucial for body-weight management, and for metabolic health. In this context, circadian alignment consists of alignment of sleep, meal patterns and physical activity. During puberty a significant reduction in sleep duration occurs, and pubertal status is inversely associated with sleep duration. A consistent inverse association between habitual sleep duration and body-weight development occurs, independent of possible confounders. Research on misalignment reveals that circadian misalignment affects sleep-architecture and subsequently disturbs glucose–insulin metabolism, substrate oxidation, leptin- and ghrelin concentrations, appetite, food reward, hypothalamic–pituitary–adrenal-axis activity and gut-peptide concentrations enhancing positive energy balance and metabolic disturbance. Not only aligning meals and sleep in a circadian way is crucial, also regular physical activity during the day strongly promotes the stability and amplitude of circadian rhythm, and thus may serve as an instrument to restore poor circadian rhythms. Endogenicity may play a role in interaction of these environmental variables with a genetic predisposition. In conclusion, notwithstanding the separate favourable effects of sufficient daily physical activity, regular meal patterns, sufficient sleep duration and quality sleep on energy balance, the overall effect of the amplitude and stability of the circadian rhythm, perhaps including genetic predisposition, may integrate the separate effects in an additive way.

Sleeping late is a risk factor for myopia development amongst school-aged children in China

“…As a consequence of involuntarily shifting between two 'time zones': one determined by our internal clock, the circadian rhythm, and the other governed by study, work or other social duties in modern societies, misalignment of biological and social time is almost universal 39 . Disturbance to the circadian clock can not only affect the academic performance of children 40 , but also cause several health problems [41][42][43] . In terms of the visual system, a number of animal studies have demonstrated the importance of regular rhythmicity of lighting conditions on normal ocular growth and emmetropisation 13,14,44 .…”

Evidence for disruption of diurnal salivary cortisol rhythm in childhood obesity: relationships with anthropometry, puberty and physical activity

“…Our findings also suggest that increased non-screen sedentary behaviours and inadequate sleep duration are associated with higher night-time cortisol output. With sleep loss, cortisol may exert its deleterious metabolic effects by maintaining high night-time concentrations, which are associated with insulin resistance (IR), suppressed immunity and increased inflammation [44]. Thus, the findings of this integrated approach indicate that the relative distribution of time spent in different physical activities within a 24-h period is important for health promotion and maintenance of diurnal cortisol rhythm in the paediatric population.…”

Does stress influence sleep patterns, food intake, weight gain, abdominal obesity and weight loss interventions and vice versa?

“…Robust epidemiological evidence supports the potential role of inadequate sleep as contributing to the current high prevalence of obesity, more specifically abdominal adiposity, in both children and adults (Table ) . There are longitudinal observations suggesting that sleep and body weight develop at least partly in parallel , so causality cannot be extrapolated from these cross‐sectional observations. However, several experimental studies confirm the link between sleep and obesity (Table ).…”