Objective Measurements of Energy Balance Are Associated With Sleep Architecture in Healthy Adults.
Level 4 - case-series / case-control
Cross-sectional observational laboratory study evaluating correlations without an intervention or control group.
PubMed 28364451 · doi:10.1093/sleep/zsw018
What was done
Fifty healthy adults aged 21–50 years participated in an in-laboratory study with two baseline nights (10 hours time-in-bed, 2200–0800 hours). Polysomnography was recorded on night two. Investigators objectively assessed body composition, energy expenditure, and daily dietary intake on the day before (BL1) and the day after (BL2) the sleep recording. Partial Pearson correlations were calculated to examine relationships between energy balance measures and sleep physiology.
What was found
Greater fat-free mass correlated with lower total sleep time (r = -0.52, p = .030), lower sleep efficiency (r = -0.53, p = .004), and increased wake after sleep onset (r = 0.55, p = .002). Higher body fat percentage (r = 0.39, p = .038) and being overweight (BMI 25–30, p = .026) were associated with more rapid eye movement (REM) sleep. Higher protein intake (r = 0.46 to 0.52, p < .001 to .002) and lower carbohydrate intake (r = -0.31 to -0.34, p = .027 to .046) were associated with more REM sleep. Higher fiber intake correlated with more slow-wave sleep (SWS; r = 0.33 to 0.35, p = .02 to .03), and greater SWS correlated with higher carbohydrate intake the following day (r = 0.32, p = .037).
Why it matters
These findings suggest that specific dietary components (such as fiber and protein) and body composition metrics are linked to objective sleep architecture stages like SWS and REM sleep in healthy adults.
Limits
The sample size was small (n = 50) and restricted to healthy adults. The correlational design prevents drawing causal conclusions, and sleep architecture was assessed on only a single polysomnography recording night.