From Sunlight to Supper: Natural Ways to Reset Your Body Clock and Beat Jet Lag

A long-awaited holiday can come with an unexpected problem: jet lag. After crossing several time zones, many travellers find themselves exhausted in the afternoon, awake in the middle of the night, or struggling to concentrate during the day.

Jet lag is one of the most common side effects of international travel. It happens because your body’s internal clock does not immediately match the local time at your destination. While your watch may say it is morning, your body may still think it is the middle of the night.

Understanding how your body clock works and learning how to use natural signals such as sunlight, meals, movement, and sleep routines can help you adjust faster and enjoy your trip with more energy.

What Causes Jet Lag?

Jet lag occurs when your internal biological clock becomes out of sync with the time zone around you.

The human body follows a natural 24-hour cycle known as a circadian rhythm. This internal system controls important functions including sleep, alertness, digestion, hormone release, and body temperature.

According to circadian rhythm researchers, the body’s master clock is located in the brain and is mainly controlled by environmental signals. One of the strongest signals is exposure to light and darkness.

When you fly across multiple time zones, your surroundings change immediately, but your body clock adjusts more slowly. Your brain may still follow the schedule of your previous location, causing symptoms such as:

• Difficulty falling asleep at the right time
• Feeling tired during the day
• Poor concentration and slower thinking
• Mood changes and irritability
• Digestive discomfort
• Reduced physical performance

In simple terms, your body may still be living on your old schedule while the outside world has already moved on.

Why Flying East Can Feel More Difficult

The direction of travel can influence how severe jet lag feels.

Many travellers find eastward journeys harder because moving the body clock earlier is usually more difficult than delaying it. For example, travelling from the UK to Asia often requires waking up and sleeping earlier than your body naturally wants to.

Westward travel can sometimes be easier because it involves staying awake later, which matches the natural tendency of many people’s body clocks.

The more time zones you cross, the greater the adjustment your body needs to make. A short flight across one or two time zones may cause mild disruption, while long-haul journeys across continents can create stronger symptoms.

How Sunlight Helps Reset Your Body Clock

Light is one of the most powerful tools for adjusting your circadian rhythm.

Morning sunlight sends signals to your brain that it is time to become alert and start a new day. Getting outside soon after waking can help your body move towards the local schedule.

If you have travelled east, exposure to morning light can help your body clock shift earlier. If you have travelled west, evening light may help your body adjust to staying awake later.

Natural outdoor light is much stronger than indoor lighting, even on cloudy days. A walk outside can therefore be more effective than simply sitting near a window.

Try to spend time outdoors at the correct local time rather than following the daylight schedule from your previous location.

Use Exercise and Movement to Adjust Faster

Physical activity can also support your body’s adjustment to a new time zone.

A gentle walk during daylight hours can help reinforce the message that it is daytime. Exercise improves alertness, supports healthy sleep patterns, and helps your body adapt to a new routine.

After a long flight, many people feel tempted to rest immediately. However, sleeping for several hours during the wrong part of the day can make jet lag last longer.

Instead, try light activity, fresh air, and exposure to natural surroundings when you arrive.

Adjust Your Meal Times

Food is another important signal for your body clock.

Eating meals according to local time can help your body understand that it has entered a new daily routine. Try to have breakfast, lunch, and dinner at appropriate local times instead of following your previous schedule.

Eating late at night may delay the release of melatonin, a hormone involved in preparing the body for sleep.

To support better sleep after travelling:

• Avoid heavy meals close to bedtime
• Eat during daylight hours when possible
• Drink enough water after flying
• Choose balanced meals that support energy levels

Changing meal timing gradually can help your digestive system adjust alongside your sleep schedule.

Improve Your Sleep Environment

Good sleep habits are essential when recovering from travel.

Even if your body clock is still adjusting, creating the right conditions can encourage better rest.

Helpful sleep hygiene practices include:

• Keeping your bedroom dark and cool
• Reducing bright lights before bedtime
• Avoiding excessive screen use late at night
• Following your normal bedtime routine
• Going to bed at your target local time

Consistency helps your brain recognise when it is time to sleep.

Should You Use Melatonin for Jet Lag?

Some travellers use melatonin supplements to help manage jet lag. Melatonin is a hormone naturally produced by the body that helps regulate sleep.

However, experts advise caution. In some countries, including the UK, melatonin is available only through prescription. Supplements sold elsewhere may differ in strength and quality, and the amount listed on packaging may not always match the actual dose.

Before using melatonin or any sleep aid, speak with a qualified healthcare professional who can advise whether it is suitable for you.

How Long Does Jet Lag Last?

The length of jet lag varies depending on several factors, including the number of time zones crossed, travel direction, sleep patterns, age, and individual body clocks.

Many people begin adjusting within a few days, but longer journeys may require more time. Supporting your body with light exposure, regular meals, movement, and healthy sleep habits can make the transition smoother.

Final Thoughts: Let Your Body Follow the Sun

Jet lag cannot be completely avoided, but it can be managed. Your body clock responds to powerful natural signals, including sunlight, food, exercise, and routine.

Instead of fighting your internal rhythm, help it adapt by following the local schedule as quickly as possible. Get outside during the right hours, eat at local meal times, stay active during the day, and create a calm sleep environment at night.

With the right approach, you can spend less time feeling tired and more time enjoying your journey.

Sources

Information in this article is based on research and expert comments from:

• Dr Nina Rzechorzek, University of Cambridge research on sleep, circadian rhythms, and human brain temperature.
• Dr Anna Edmondson, Laboratory of Molecular Biology, University of Cambridge, research on biological clocks.
• Dr Tatiana Wilson, circadian researcher at Newnham College, University of Cambridge.

Original reporting reference: BBC, published on 6 August 2026.

Disclaimer

This article is for general informational purposes only and does not provide medical advice. Individual responses to jet lag, sleep disruption, or supplements may vary. If you have ongoing sleep problems, medical conditions, or questions about using medication such as melatonin, consult a qualified healthcare professional.