Hannah Wagner keeps a tin of tuna tucked behind the bar at Dark Red, the Fortitude Valley wine bar she owns. On a late shift, crouching between pouring glasses of chilled red, she will pick at it rather than eat a full meal. After midnight, she avoids rice and pasta, sticking to vegetables. “That’s just a tried and tested thing,” she says. Her rhythms are those of a night owl: sleep rarely comes before midnight, mornings begin after 9.30, and breakfast is a meal she skips. It is a pattern that, viewed from a laboratory in Queensland, turns out to be far more than personal preference.

Researchers at Griffith University recently mapped the eating windows of 287 women across Europe and New Zealand and found that evening chronotypes—night owls—consume roughly the same calories as early risers but shift their intake dramatically toward late hours. After 8 p.m., they reach for foods higher in energy, carbohydrates and fats, while eating less between 3 a.m. and 10 a.m. The metabolic cost, the study suggests, is measurable: higher body fat percentages, elevated blood sugar and lipids, and a greater risk of poor metabolic health. Professor Rozanne Kruger, who led the work, notes that the body is primed to fast and sleep at night; eating against that rhythm means storing more energy rather than using it. “It does matter what you eat, but it definitely matters when you eat it,” she says.

That insight is landing in a world already anxious about rest. In Tehran, health pages are warning readers that chronic night waking may do more than leave them groggy: it can impair the brain’s ability to clear amyloid beta, the protein that forms the plaques associated with Alzheimer’s disease. Even a single night of severe sleep deprivation, Iranian reports note, can temporarily raise amyloid levels, though the gravest risk accumulates over years of insomnia or untreated sleep apnoea. Meanwhile, a Washington University study tracking 230 women from early pregnancy through the postpartum period found that disrupted sleep was linked to higher rates of perinatal anxiety, with about 15 per cent developing anxiety-related disorders. Nigerian obstetricians, responding to the findings, describe a cultural landscape in which new mothers are expected to receive visitors and manage households rather than rest, compounding the exhaustion of night feeds.

Across continents, the advice is converging on small, specific adjustments. Indonesian nutritionists recommend a plate of white rice an hour before bed, paired with a tryptophan-rich protein such as chicken or egg, to help the body produce melatonin and serotonin. Almonds, oatmeal and kiwi fruit appear on similar lists for their magnesium, complex carbohydrates and serotonin content. A Nigerian health column, answering a reader’s question about eating oranges at night, cautions that while the fruit’s vitamin C and fibre are beneficial, its acidity can trigger reflux if consumed immediately before lying down; the counsel is to eat at least an hour before sleep and to listen to the body’s signals. In Mexico, health authorities urge people to see a doctor when fatigue persists for weeks, listing anaemia, thyroid disorders and sleep apnoea among the possible culprits behind a tiredness that no amount of coffee can fix.

What emerges is a portrait of sleep not as a passive absence of wakefulness but as a physiological event shaped by the clock, the plate and the culture that surrounds both. The tin of tuna behind the bar, the orange left on a nightstand, the bowl of oatmeal eaten as a late-night snack—each is a small, private calibration. And in the quiet of a wine bar after closing, with the last glass polished and the street silent, Wagner’s midnight meal of vegetables and protein is less a quirk than a quiet accommodation to a body that keeps its own time.