A Systematic Review, Meta-Analysis and Meta-Regression on the Effects of Carbohydrates on Sleep

Abstract

This study aimed to assess the effects of quantity, quality and periodization of carbohydrates consumption on sleep. PubMed, SCOPUS and Cochrane Library were searched through October 2020. Data were pooled using random-effects meta-analysis. Eleven articles were included in the meta-analysis which consisted of 27 separate nutrition trials, resulting in 16 comparison data sets (sleep quantity n = 11; sleep quality n = 5). Compared to high carbohydrate (HCI), low carbohydrate intake (LCI) moderately increased duration and proportion of N3 sleep stage (ES = 0.37; 95% CI = 0.18, 0.56; p < 0.001 and ES = 0.51; 95% CI = 0.33, 0.69; p < 0.001, respectively). HCI prolonged rapid eye movement (REM) stage duration (ES = −0.38; 95% CI = 0.05, −8.05; p < 0.001) and proportion (ES = −0.46; 95% CI = −0.83, −0.01; p < 0.001), compared to LCI. The quality of carbohydrate intake did not affect sleep stages. Meta-regression showed that the effectiveness of carbohydrate quantity and quality in sleep onset latency was significantly explained by alterations of carbohydrate intake as a percentage of daily energy intake (R2 = 25.87, p = 0.018) and alterations in the glycemic load (R2 = 50.8, p = 0.048), respectively. Alterations in glycemic load partially explained the variance of the effectiveness of carbohydrate quality in sleep efficiency (R2 = 89.2, p < 0.001) and wake after sleep onset (R2 = 64.9, p = 0.018). Carbohydrate quantity was shown to affect sleep architecture, and especially N3 and REM sleep stages. Alterations in both quantity and quality of carbohydrate intake showed a significant effect on sleep initiation. Variations in carbohydrate quality significantly affected measures of sleep continuation. Further studies are needed to assess the effect of long-term carbohydrate interventions on sleep.

Food consumption according to the level of processing and sleep quality during the COVID-19 pandemic

“…As shown in a systematic review of 19 studies with 86,961 individuals, where the highest caloric contribution of carbohydrates and fats in the diet, had the worst night's sleep [48]. A review study suggested that hyperglycemia-induced after a high sugar diet and the resulting compensatory hyperinsulinemia could induce the release of autonomic counterregulatory hormones, including adrenaline, cortisol, glucagon, and growth hormone [26], leading to shorter time in deep sleep, and therefore non-restorative sleep [49]. Furthermore, high sugar consumption may also contribute to a higher inflammatory profile [50], which may negatively impact sleep [51].…”

Intake of l-serine before bedtime prevents the delay of the circadian phase in real life

“…Although animal studies suggested that trehalose has effects in neurodegenerative diseases such as Huntington's disease [38], Alzheimer's disease [39], and ALS [40], there has been no study in which the relationship between trehalose ingestion and circadian rhythms was investigated in animals and humans. On the other hand, it has been reported that carbohydrate intake is related to sleep and circadian rhythms in humans through blood glucose levels [41,42]. In addition, animal studies have shown that insulin directly affects the peripheral circadian clock [43,44].…”

Carbohydrate and sleep: An evaluation of putative mechanisms

“…A meta-analysis, related carbohydrate consumption to the amount of time spent in different stages of sleep ( 80 ). It was found that the amount of carbohydrate consumed influenced sleep architecture: a higher intake was associated with less SWS and more REM.…”