Chrononutrition: are you eating your meals in the wrong order?

For more like this, check out our guides to how much sleep do you need, how to have a better night's sleep and how to improve your morning coffee routine.

What is chrononutrition?

Chrononutrition is based on the idea that your body’s internal clock (aka your circadian rhythm) influences how well you digest and process food at different times of the day. Essentially, eating in sync with your body’s natural rhythms can help you improve your metabolism, energy levels and overall health.

Ever eaten a pizza at 10pm than tossed and turned all night? Congratulations, you’ve already experienced it.

But this isn’t about lecturing you on your eating schedule – after all, you should do what works best for you. However, there could be concepts of chrononutrition that could genuinely benefit you: for example, if you struggle with energy crashes, weird cravings or bad sleep. In fact, multiple studies have explored the timings of meals and the impact it has on a person.

What is your circadian rhythm?

Your circadian rhythm is your body’s internal 24-hour clock that regulates things like sleep, metabolism, hormone levels and even digestion. It’s influenced by light, food and other external cues, helping your body know when to wake up, feel hungry and wind down for sleep.

For example, in the morning your body releases cortisol which wakes you up and gets more efficient at processing food. In the afternoon, you might hit an energy slump as your body’s internal clock naturally dips, and at night your body produces melatonin which helps you sleep.

When your circadian rhythm is working well, you’ll likely feel more energised during the day and sleep better at night. But when it’s out of kilter, for example from things like jet lag, shift work or irregular eating and sleep schedules, that’s when you can feel tired, hungry at odd times or just generally not yourself.

Pillow alarm clock. The concept of sleep problems, insomnia, circadian rhythm.

How could chrononutrition benefit you?

If you feel tired in the morning, no matter how much you’ve slept

Your alarm goes off, you’ve had your morning coffee, yet you can’t seem to shake that sluggish feeling. Your eating habits might be part of the problem.

Cortisol is often at its highest in the morning – for most usually around 7am. The ‘cortisol awakening response’ helps prepare your body for the day by increasing your alertness, energy and blood sugar levels. Sounds great, however, when your cortisol levels are raised too high you might feel jittery, irritable, anxious and less focussed. Hence why cortisol is also known as our stress hormone.

Foods high in added sugar, caffeine and processed ingredients can raise cortisol levels, especially in the morning. If this sounds familiar, consider delaying your caffeine intake by an hour or so, or ensuring you eat first. If you’re someone that opts for a convenient, on-the-go croissant, try switching to a savoury breakfast which could stabilise blood sugar spikes, help you feel fuller for longer and more energised throughout the day.

“The timing of nutrients can have an impact on how you’re feeling,” explains registered nutritionist Jemma Joel. “A savoury breakfast is likely to keep you fuller for longer as it causes less of a spike in blood sugar levels and will be more slowly digested, sustaining energy levels thanks to protein and fat being slow-digesting nutrients.”

Omelette Filled with Green Vegetables on a Plate with Tomatoes

If you feel like a sloth after lunch

A big, carb-heavy lunch can hit some like a tranquilliser dart, especially if it causes your blood sugar levels to spike, then crash. This is by no means suggesting to cut carbs but instead look at adding more protein or fibre to your midday meal, potentially keeping your energy steady. Try a lunch that mixes protein, healthy fats and complex carbohydrates – for example, grilled chicken with quinoa and roasted veggies instead of a giant plate of pasta.

Eating a big lunch can also divert a lot of energy towards digestion, making some feel a little sleepy. If this is you, consider having a smaller lunch portion, bookending your midday meal with a balanced snack instead. Or try to take a short walk after eating, as this can aid digestion and help regular blood sugar to stave off the sluggishness.

However, you shouldn’t be skipping breakfast or dinner. “Eating earlier in the day and regularly throughout the day helps to provide our bodies with the energy it requires, and avoids us overeating later in the day from genuine hunger,” adds Jemma.

Herby Grilled Chicken Wraps with Rocket and Tomatoes

If late-night eating is ruining your sleep

Your digestion slows down at night, especially as melatonin can interfere with how well your body processes food. Not only can this disrupt your sleep but research has found that late eating is associated with increased obesity risk.

“Our body needs adequate time – around one to two hours – to digest our food before going to bed, otherwise it can impact energy levels and sleep,” explains Jemma. “Digestion increases our heart rate, too, and a higher heart rate before bed can make it harder to switch off and have a restful night’s sleep.”

If you’re someone that struggles to get off to sleep, consider moving your evening meal a little earlier. This is also important if you suffer with acid reflux or heartburn. According to the Sleep Foundation, eating too close to bedtime is related to gastroesophageal reflux disease (GERD) and acid reflux. When a person lies down right after eating, the contents of the stomach can press against the lower oesophageal sphincter which can cause irritation and dreaded acid reflux.

Opt for foods that aren’t heavy to digest and can support relaxation and steady blood sugar levels. Try protein and complex carb combos like salmon and quinoa, tofu and brown rice, or chicken and sweet potato, adding in magnesium-rich foods like leafy greens or avocado.

If you’re someone that likes a late-night snack (after all no one wants to go to bed hungry), something light and easy to digest is a good option, like greek yogurt and honey, a slice of wholegrain toast with butter, or a banana with almond butter.

And it might help you feel good the next day. “Being mindful of the timing of our evening meal and the nutritional components can support with energy levels and mood the next day, too,” says Jemma. “If we wake up feeling rested and happy then we’re more likely to achieve more.”

USA, New Jersey, Jersey City, Morning in bedroom

If you want to maximise your energy when working out

Whether you’re lifting weights, running or making it through a spin class, timing your meals could help you feel fuelled and focussed, and maximise the benefits of your workout, too.

“Your diet may vary depending on your exercise goals – for example, eating more protein if you’re trying to build muscle,” explains Jemma. “However, for the most part, if you're simply trying to stay fit and healthy then having three balanced and satiating meals throughout the day with a source of protein, fats, carbs and veggies, alongside balanced snacks where needed, will provide your body with the energy it needs to support your workouts and recovery.”

The post-workout period is often considered the most critical part of nutrient timing, known as the ‘anabolic window’, the 30- to 60-minute period after exercise where your muscles are meant to be most primed to absorb nutrients. Aim for a post-workout snack or meal that includes a combination of carbohydrates to replenish glycogen and protein which supports muscle repair. For example, chicken and rice, a protein smoothie or eggs on wholegrain toast.

If you’re always hungry

If you struggle with constant cravings and feelings of hunger it could be down to when you’re eating throughout the day. Eating irregularly, skipping meals or having mostly quick-digesting carbs (for example, white bread and white pasta) can cause blood sugar spikes and crashes, which triggers hunger.

Try eating at regular intervals – for example, every three to five hours, and ensure your meals and snacks pair protein and fibre with complex carbs to slow digestion and keep energy levels stable. And, remember, your body's ability to process food is at its peak earlier in the day. If you're eating light meals during the day and loading up at night, your hunger hormones might be out of sync. Having a bigger breakfast could help control cravings later, while eating enough protein earlier in the day can also improve satiety.

Eating at a similar time each day could also help with hunger. Two key hormones – ghrelin (hunger hormone) and leptin (fullness hormone) – are influenced by meal timings, with ghrelin levels rising before a meal to stimulate your appetite and leptin levels increasing after eating to signal satiety and suppress hunger. Skipping meals or eating erratically can increase ghrelin, making you feel hungrier, so consistent meals at similar times can help regulate these hormones.

Close up shot of people sitting at dining room table with plates of vegetables and salad, person serving guests at dinner party, man about to pour dressing on his meal

Research into chrononutrition is still ongoing and it’s important to remember, like most things, there’s not a one size fits all approach. If your eating schedule works for you, then carry on doing what you’re doing. But if you’ve been dealing with weird energy dips, bad sleep or feeling like you constantly need to snack, then shifting your meal timings, and what you eat during those meals, could help.

“What works for one person might not work for another so it’s worth experimenting and making small tweaks to meals and snacks, and noting how you feel in terms of mood, energy and what you want to achieve with your personal health goals,” advises Jemma.

It’s not about food shaming or strict rules – just another suggestion to see if adapting your nutrition plan can help you feel better. After all, there’s more to think about in life than stressing over the exact timing of your sandwich.