Effects of sleep restriction on metabolism-related parameters in healthy adults: A comprehensive review and meta-analysis of randomized controlled trials.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of randomized controlled trials.
PubMed 30870662 · doi:10.1016/j.smrv.2019.02.002
What was done
A systematic review and meta-analysis was conducted across six electronic databases through January 2018 to examine the effects of sleep restriction on metabolic parameters in healthy adults. The review identified 41 randomized controlled trials that evaluated subjective hunger, appetite-regulating hormones, brain activity changes, energy intake and expenditure, weight change, and insulin sensitivity or resistance.
What was found
Sleep restriction significantly increased subjective hunger on a 100 mm scale (mean difference = 13.4, p < 0.001) and daily caloric intake (mean difference = +252.8 kcal/d, p = 0.011). Partial sleep restriction led to a weight gain of 0.34 kg (p = 0.003) and decreased insulin sensitivity (standardized mean difference = -0.70, p < 0.01). Significant changes in brain activity in response to food stimuli occurred in reward- and cognitive control-related regions. No strong evidence supported a significant impact on mean leptin, ghrelin, or energy expenditure.
Why it matters
This meta-analysis demonstrates that sleep restriction drives a positive energy balance primarily by increasing appetite and caloric intake rather than decreasing energy expenditure, alongside causing acute impairments in glycemic control.
Limits
The abstract does not report the total participant sample size, study durations, or confidence intervals for effect sizes. Findings are limited to healthy adults under controlled, typically short-term experimental conditions and cannot be directly generalized to chronic, real-world sleep curtailment or clinical populations.