The best time to eat every meal, according to science

Growing evidence suggests that when you eat matters just as much as what you eat, and that consuming meals in line with your body clock may play an important role in overall health. 

This is an emerging area of research – called chrononutrition – which looks at how food intake interacts with our circadian rhythm. “Our circadian rhythms determine when to sleep, rise, eat, as well as many other physiological processes,” explains Alexandra Johnstone, professor of human nutrition research at University of Aberdeen. “The master body clock is affected by environmental cues, particularly sunlight and a change in time zone – but also when you eat.”

Circadian rhythms and metabolism are closely linked, adds Jonathan Johnston, professor of chronobiology and integrative physiology at the University of Surrey. “Meal timing is an important synchronising cue for some of our metabolic rhythms. Meal timing strategies are often reported to benefit metabolic physiology, help with weight loss and/or improve appetite control.”

A French study published in Nature in 2023 found eating an earlier breakfast and earlier dinner may be associated with a reduced risk of heart attack and stroke. Other research, like the randomised clinical trial published in JAMA Internal Medicine, suggests early restricted eating is more effective for supporting weight loss and lowering blood pressure in adults with obesity, compared with eating over a 12-hour period or more. Meanwhile, Zoe research suggests simply limiting your daily eating schedule to a set 10-hour “window” (thus creating a 14-hour overnight fast) may improve hunger, mood and sleep.

With this in mind, we asked experts exactly when to eat breakfast, lunch and dinner – and when to snack – for the best health benefits.

Have breakfast 12 to 14 hours after your last evening meal, ideally within two hours of waking 

There is no single “best” time to eat breakfast, stresses Dr Sarah Berry, professor of nutritional sciences at King’s College, London and chief scientist at Zoe, as this is highly individual. It depends on things such as your sleep patterns, your chronotype (whether you are a morning or evening person), and when you had your last meal the night before, she says. “As a general rule of thumb, evidence shows it’s better to consume more of your calories earlier in the day when we are more insulin sensitive.”

That said, it’s important to listen to your body and your hunger signals. “If you’re the kind of person that wakes up hungry, have breakfast. If you’re the kind of person that isn’t hungry first thing in the morning, then it’s okay to wait,” Berry advises.

Evidence suggests that factoring in an overnight fast period of around 12 or 14 hours (in which you don’t have anything to eat or drink, except water) – a form of time restricted eating – “can improve your weight and metabolic health, including measures like inflammation, blood pressure and cholesterol”, she says. If you are aiming for a 14-hour fast, that could involve having your last meal at 7pm and breakfast at 9am. “Others prefer to eat later, though research does suggest greater benefits for those who start and finish earlier.” Fasting also benefits the gut microbe.

Priya Tew, director of Dietitian UK, believes it’s generally best to eat breakfast within a couple of hours of waking. “This gives your body a chance to digest and absorb the nutrients.” For some people, delaying breakfast too long can make them feel tired and hungrier, “because your body’s been waiting for food, so you might eat a large amount in one go”.

Tew adds that if you’re hitting the gym first thing, she always recommends having something small beforehand, “then topping up afterwards so you’ve got energy for the day”.

Eat your biggest meal in the morning

A study led by Johnstone and co-authored by Johnston, published in scientific journal Cell Metabolism in 2022, compared morning-loaded diets (where participants ate the bulk of daily calories in the morning) with evening-loaded diets, and found that morning-loaded diets may help regulate appetite. Participants reported feeling less hungry when having a bigger breakfast and a smaller dinner, in contrast to when they consumed more calories in the evening.

Sync with your body clock

“As humans, our physiology is partially regulated by the circadian system, which is adapted for activity in the daytime and rest in the nighttime, meaning our body is set up to digest optimally in the daytime,” says Tew.

We are more insulin-sensitive earlier in the day and this decreases in the evening, Berry explains. “So if you’re consuming carbohydrates in the morning, you will have a more balanced blood sugar response. This means less energy dips after carbohydrates.”

Make lunch equidistant between breakfast and dinner

Spacing out meals evenly throughout the day encourages our body to be metabolically efficient, according to Tew. “It gives us enough time to digest between each meal and can also help with energy levels.” She highlights how best practices can vary by person, based on their own unique systems. “For people with sensitive digestive systems or IBS, particularly, having small frequent meals and avoiding going longer than, say, four hours between eating is key to avoid issues like bloating and pain.”

If you snack, focus on quality rather than timing 

“Our Zoe Predict research found that in the UK, around 25 per cent of our energy intake comes from snacks. People tend to snack two to three times a day, on average, and these snacks are typically high in salt, sugar, and saturated fat, and low in fibre and healthy proteins,” Berry says. “Our research showed the quality of snacks is what matters, not the frequency. So if you are a snacker, changing the quality of your snacks – opting for nuts over crisps, for example – rather than cutting them out, is the simplest dietary strategy to increase your health.”

Aim for a 6pm supper

In an ideal world, having dinner around 6pm would be best, agree the experts. “I have my dinner at this time because I have children and that’s family teatime for us, but for lots of people this is completely impractical,” says Tew. “The benefits of an earlier dinner are that it gives you time to digest your food before going to bed. Some people might have an evening snack, and this leaves time for that. But don’t beat yourself up if this isn’t possible.”

People often point to Mediterranean countries where dinner is typically eaten later, adds Berry. “They do, but most have their main meal at lunch, unlike the UK.”

No snacking after 9pm 

“Recent Zoe research suggests that people who continue to eat after 9pm have an increased risk of metabolic dysfunction, factors like higher blood pressure, higher levels of inflammation and higher blood fat cholesterol levels,” says Berry.

The aforementioned French study led by researchers at the Barcelona Institute for Global Health and Université Sorbonne Paris Nord found eating dinner after 9pm was associated with a 28 per cent increase in the risk of cerebrovascular disease such as stroke compared with eating before 8pm, particularly in women.

Eating late may even make you feel more hungry. Studies have shown that late eating increases hunger, decreases energy expenditure and modifies metabolic pathways in adults who are overweight or obese.

The takehome message 

When it comes to meal timing, there is no “one size fits all approach”, Tew emphasises. “We’ve got to work around the practicalities of life. The key is to meet your body’s nutritional needs in whatever way you can.”