Ask Onix
The modern three-meal habit under scrutiny
The long-standing tradition of eating three meals daily-breakfast, lunch, and dinner-may not be the healthiest approach, researchers suggest. Emerging studies on intermittent fasting and meal timing are reshaping how we think about daily food intake.
The case for fasting: Resting the digestive system
Scientists emphasize the benefits of giving the body extended breaks from food. Emily Manoogian, a clinical researcher at the Salk Institute for Biological Studies, explains that fasting for at least 12 hours allows the digestive system to rest. This practice aligns with findings from her 2019 study, "When to Eat," which highlights the body's ability to repair and regulate itself during fasting periods.
Rozalyn Anderson, an associate professor at the University of Wisconsin's School of Medicine and Public Health, adds that daily fasting can reduce inflammation and help the body clear misfolded proteins-faulty molecules linked to diseases like Alzheimer's and diabetes. "Fasting puts the body in a state where it's better prepared to repair damage," she says.
Blood sugar control and meal timing
Antonio Paoli, a professor of exercise and sport sciences at the University of Padova, notes that fasting improves the body's glycaemic response-the rise in blood sugar after eating. Smaller glucose spikes reduce fat storage and lower the risk of diabetes and heart disease. Paoli's research suggests that eating dinner earlier and extending the overnight fast enhances these benefits.
"Lower sugar levels in cells prevent glycation, a process where glucose binds to proteins, forming harmful compounds that trigger inflammation," Paoli explains. High blood sugar over time is a known risk factor for chronic diseases.
One meal a day: A radical approach?
Some experts advocate for a single daily meal. David Levitsky, a professor at Cornell University's College of Human Ecology, follows this routine himself. He argues that frequent exposure to food-whether through sight or habit-leads to overeating. "Before modern conveniences, humans ate when food was available, often just once a day," he says, citing historical examples like the Ancient Romans, who ate a single midday meal.
However, Manoogian cautions against this approach. Skipping multiple meals can elevate fasting glucose levels, a risk factor for type 2 diabetes. "The body may release excess glucose in response to perceived starvation," she warns. Instead, she recommends two to three meals, with most calories consumed earlier in the day to align with the body's natural rhythms.
The risks of late-night eating
Eating late at night poses challenges for the body. Manoogian explains that melatonin, released during sleep, suppresses insulin production, which helps regulate blood sugar. Consuming calories when melatonin levels are high-such as late at night-can lead to dangerously high glucose levels. "The body struggles to store glucose properly when insulin is suppressed," she says, increasing the risk of diabetes over time.
This doesn't mean breakfast should be skipped entirely, but waiting an hour or two after waking may be beneficial. "Eating too soon after waking works against our circadian rhythm," Manoogian notes.
A brief history of meal patterns
Food historian Seren Charrington-Hollins traces the evolution of meal habits. The Ancient Greeks introduced breakfast, but it was a luxury reserved for the aristocracy. The Industrial Revolution cemented the three-meal norm, as factory schedules demanded structured eating times. However, food shortages during wartime disrupted this routine, and the modern breakfast-cereal and toast-only became widespread in the 1950s.
"Over centuries, we've been conditioned to three meals a day, but this is being challenged. Our sedentary lifestyles mean we need fewer calories than in the 19th century."
Seren Charrington-Hollins, food historian
Practical advice: Consistency over rigidity
While research suggests two to three meals with an extended overnight fast are ideal, Manoogian acknowledges that rigid schedules may not suit everyone. "Telling people to stop eating by 7 p.m. isn't helpful for those with irregular hours," she says. Instead, she advises small adjustments, such as delaying the first meal and eating dinner earlier, to create a consistent fasting window.
Anderson emphasizes the importance of routine. "The body thrives on patterns. Intermittent fasting imposes a structure that helps biological systems anticipate and process food efficiently."
The future of meal habits
Charrington-Hollins predicts a shift away from the three-meal norm as work patterns and lifestyles evolve. "Food is everywhere now, and our caloric needs have changed. Long-term, we may return to a lighter meal and a main meal, driven by work schedules."
For now, experts agree that consistency-whether in meal timing or fasting windows-is key to optimizing health. Small, sustainable changes, like adjusting meal times, can yield significant benefits without drastic overhauls.
