Research

Hormonal

Consumption of carbohydrates with a high glycemic index (GI) shortly before bedtime reduces sleep latency (time to fall asleep) by increasing insulin-mediated tryptophan transport to the brain, whereas high-GI diets consumed chronically increase the risk of insomnia.

If you struggle to fall asleep, try eating a carbohydrate-rich meal (like pasta or rice) about 4 hours before bed. The resulting insulin spike helps tryptophan enter your brain, potentially speeding up sleep onset. However, do not make high-sugar/refined carb foods your daily staple, as this chronic pattern increases the risk of developing insomnia.

ModerateConditionalMEDIUM confidence
A study that was conducted in a group of 12 healthy subjects who were aged 18–35 years, and who consumed a meal that contained carbohydrates with a high glycemic index (GI) four hours before bedtime, showed a significant reduction in the delay in falling asleep, compared to a meal that contained low GI products [69]. ... The risk of insomnia was increased by products with higher glycemic indexes and higher amounts of added sugars, refined grains, and starches. By contrast, a higher consumption of dietary fiber, whole grains, fruit, and vegetables was associated with a lower risk of insomnia [70].
Monika Sejbuk et al. · Nutrients · 2022

Why this rating

The paper is a narrative review citing observational studies and small acute trials (n=12) rather than large-scale RCTs.

Source

Sleep Quality: A Narrative Review on Nutrition, Stimulants, and Physical Activity as Important Factors

Monika Sejbuk et al. · Nutrients · 2022

DOI 10.3390/nu14091912

narrative_reviewCited 368×
Read the paper
DOI resolved against Crossref · corpus check 2026-06-10

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