People who eat a lot of fibre spend more time in deep sleep
New Scientist
March 2, 2026
AI-Generated Deep Dive Summary
Eating more fiber and a variety of plant-based foods may improve sleep quality by increasing time spent in deep sleep, which is crucial for physical and mental health. A study involving over 3,500 adults found that those who consumed higher-than-average levels of fiber slept better, spending 3.4% more time in the restorative N3 sleep stage and less time in lighter sleep. Additionally, individuals with diverse plant-based diets fell asleep faster and had a lower heart rate during sleep.
The research utilized detailed dietary tracking through mobile apps and advanced sleep monitoring devices to measure sleep stages accurately. Unlike previous studies that relied on self-reported diet data or basic sleep trackers, this study objectively assessed factors like snoring, blood oxygen levels, and heart and breathing rates. By controlling for variables such as age, sex, caffeine intake, and prior day’s diet, the researchers isolated the impact of daily food choices on nighttime sleep.
The findings suggest that gut microbes may ferment fiber into short-chain fatty acids like butyrate, which reduce inflammation and influence gut-to-brain signaling to promote deep sleep. A lower nocturnal heart rate observed in high-fiber consumers indicates a state of deep rest, potentially offering long-term cardiovascular benefits if sustained over time. The study highlights the importance of incorporating a variety of fruits, vegetables, and nuts into meals for better sleep health. This discovery aligns with existing recommendations for a fiber-rich diet, offering an additional benefit for those already prioritizing their overall well-being.
This research matters because poor sleep is linked to chronic diseases like obesity, diabetes, and cardiovascular issues. By identifying dietary factors that enhance deep sleep quality, it provides actionable advice for individuals seeking natural ways to improve their sleep health. For science enthusiasts, this study underscores the interconnectedness of diet, gut microbiome, and sleep mechanisms, offering new insights into holistic approaches to wellness.
The findings are particularly relevant for public health, as they suggest simple dietary adjustments—like eating more fiber and plant-based foods—can have a tangible impact on sleep quality without requiring expensive interventions. For anyone looking to enhance their nighttime rest, prioritizing a diverse and fiber-rich diet may be a key step toward better sleep and overall health.
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Originally published on New Scientist on 3/2/2026