Contents:

• Circadian rhythm and digestion – why is mealtime important?
• What to eat in the morning? The perfect breakfast aligned with your internal clock
• What should you avoid in the evening? Meals that disrupt sleep and metabolism.
• What does a circadian dinner look like? What should you eat in the evening to sleep better?

In an era of growing health awareness, more and more people are realizing that not only what we eat but also when we eat is crucial for our health, well-being, and metabolism. Our body operates according to a biological clock – the so-called circadian rhythm – which regulates many physiological processes such as sleep, hormone secretion, digestion, and body temperature. Understanding how our circadian rhythm affects food processing at different times of day can be key to developing effective eating habits. In this article, we take a closer look at what's best to eat in the morning and what's better to avoid in the evening to stay in harmony with our body's natural rhythm.

Circadian rhythm and digestion – why is mealtime important?

Every cell in our body has its own internal biological clock. However, the suprachiasmatic nucleus (SCN) in the hypothalamus is the primary "conductor" for regulating the circadian rhythm. The SCN primarily responds to light but also to other signals, such as mealtime. That’s why morning sunlight and the first meal of the day have such a strong influence on how the body sets its clock for the entire day.

Digestion, enzyme secretion, insulin resistance, body temperature, and glucose metabolism – all these processes are significantly more active in the morning and daytime and gradually slow down after nightfall. Therefore, the body is prepared for intense digestive activity in the morning, while it prepares for sleep and recovery in the evening. Heavy, calorie-rich meals in the evening can disrupt this natural rhythm and lead to poor sleep quality, fat storage, and metabolic issues.

What to eat in the morning? The perfect breakfast aligned with your internal clock

The morning is the moment when the body wakes up – cortisol levels rise, body temperature increases, and digestion is activated. It is the perfect time to fuel your body with energy and nutrients so you can start the day well.

What is worth eating in the morning?

• Complex carbohydrates: Whole grain bread, oatmeal, porridge (e.g., millet, buckwheat), sugar-free cereals – they provide long-lasting energy and prevent sudden blood sugar spikes.
• Protein: Eggs, dairy products (plain yogurt, cottage cheese), legumes, tofu – support regeneration and satiety.
• Healthy fats: Nuts, seeds, avocado, olive oil – support brain function and improve vitamin absorption.
• Vegetables and fruits: rich in vitamins, fiber, and antioxidants – e.g., vegetable salads, smoothies, fresh fruit (especially berries, apples, kiwi).
• Water and herbal teas: help rehydrate the body after a night's sleep and support digestion.

An example of a breakfast in harmony with the circadian rhythm:

Oatmeal with plant milk, walnuts, blueberries, and a spoonful of flaxseeds, accompanied by ginger tea and a glass of warm water with lemon – filling, anti-inflammatory, and metabolism-boosting.

Avoid in the morning: empty calories (sweets, sugary breakfast cereals), excess saturated fats (bacon, fried sausages), sugary drinks – they can disrupt sugar and insulin levels at the start of the day.

What should you avoid in the evening? Meals that disrupt sleep and metabolism.

In the evening, the body switches to recovery mode. Melatonin is released, and the production of insulin and digestive enzymes decreases. During this time, metabolism slows down and digestion becomes less efficient. Therefore, consuming heavy or calorie-rich meals in the evening can lead to the following:

• deterioration of sleep quality,
• stomach problems (e.g., reflux, bloating),
• higher risk of weight gain,
• Dysregulation of sugar and hormone levels.

What should you especially avoid in the evening?

• Red meat and fatty foods: They are hard to digest and remain in the stomach for a long time.
• Sweets and simple carbohydrates: They cause a sharp rise in blood sugar levels, followed by a rapid drop, which can disturb sleep.
• Alcohol: While it may initially promote sleep, it disrupts the REM phase and sleep quality.
• Caffeinated beverages: Coffee, cola, strong tea – even several hours before bedtime can impair falling asleep.
• Fast-food snacks: These often contain trans fats, salt, and sugar – a combination that burdens the digestive system and disrupts the circadian rhythm.

What does a circadian dinner look like? What should you eat in the evening to sleep better?

Dinner should be light and easy to digest, eaten at least 2-3 hours before bedtime. It's not about going hungry but sparing the digestive system, which needs rest during this time. A balanced dinner can even aid sleep, calm the nervous system, and promote recovery.

What to eat in the evening?

• Boiled or steamed vegetables – e.g., zucchini, carrots, broccoli, pumpkin – light and fiber-rich.
• Sources of light protein: soft-boiled eggs, boiled poultry, fish, tofu, plain yogurt.
• Sleep-promoting products: Bananas (source of tryptophan), flaxseeds, pumpkin seeds, walnuts – support melatonin production.
• Porridge and rice: easily digestible complex carbohydrates that don't overload the digestive system.
• Herbal teas: Lemon balm, chamomile, lavender – have a calming effect.

Example of a dinner following the circadian rhythm:

Pumpkin cream soup with pumpkin seeds and a tablespoon of olive oil, served with a hard-boiled egg and a slice of whole-grain bread. Finish with lemon balm tea and 2-3 walnuts.

Consciously adjusting your diet to your circadian rhythm doesn't require drastic changes but can bring enormous health benefits – from better sleep quality and stable energy levels to easier maintenance of a healthy weight. In short:

• Morning : Eat hearty, satisfying, and balanced meals – this is the time to recharge and build energy.
• Evening : Focus on lightness, calm, and regeneration – eat less, choose products that support sleep.

Your body works like a clock – help it stay in rhythm, and it will reward you with health and balance.