People who eat more fibre than average tend to spend more time in deep, restorative sleep — and fall asleep faster if they eat a wider variety of plants. Those are the findings from an analysis of more than 3,500 adults, with an average age of 53, whose diets and sleep patterns were tracked simultaneously.
According to the report, participants logged their food intake in a mobile app during or shortly after eating, across two consecutive days. At night, they wore an FDA-approved multi-sensor device on the chest, wrist, and finger that tracked snoring, blood oxygen levels, and heart and breathing rates — enabling researchers to distinguish between light sleep (N1 and N2), deep sleep (N3), and REM sleep.
The study’s lead researcher, Hagai Rossman at the Weizmann Institute of Science in Israel, says the design was intentional. “Controlling for the previous day really allowed us to explore how what you eat in the day affects your next night of sleep,” he says.
What the fibre data showed
The cohort’s average fibre intake was 21 grams per day — roughly equivalent to 2.5 cups of peas. Participants who ate above that threshold spent 3.4 per cent more time in N3 deep sleep and 2.3 per cent less time in light sleep compared to those below it.
The high-fibre group also recorded a slightly lower nocturnal heart rate than the low-fibre group — a difference of 1 beat per minute. Marie-Pierre St-Onge at Columbia University notes the nightly gap seems small. “If that difference is sustained over decades or a lifetime, that could make an important difference for cardiovascular health,” she says.
The mechanism is not fully established. Rossman points to research suggesting gut microbes ferment fibre into short-chain fatty acids — including butyrate — that reduce inflammation and alter gut-to-brain signalling in ways that promote deeper sleep.
Plant variety and sleep onset
Participants who ate more than five types of plant-based foods per day fell asleep slightly faster and had a lower nocturnal heart rate than those who ate fewer. Researchers attribute this to the broader range of vitamins, minerals, and polyphenols that a varied plant diet provides.
Earlier research in this area relied on diet recall surveys completed weeks or months after eating. Most sleep measurements used movement trackers that cannot separate sleep stages. This study used real-time food logging and a clinically validated sensor array — making it, according to St-Onge, more detailed than prior work. “Previous studies haven’t looked at so many dietary and sleep factors,” she says.
Rossman frames the dietary shift as low-risk with potential upside: “Increasing fibre and plant variety is already recommended for overall health, carries low risk for most people and may offer sleep benefits as an additional upside.”
Photo by Flüssiges Eiweiß on Pexels
This article is a curated summary based on third-party sources. Source: Read the original article
