How does time change affect diabetes?
Learn how seasonal time changes and changing time zones could affect diabetes management.
Learn how seasonal time changes and changing time zones could affect diabetes management.
Changes in time due to seasonal time changes or changing time zones due to travel may bring unique challenges to managing diabetes.
In this article, we explain how seasonal time changes in spring (i.e. British Summer Time) and autumn, as well as when travelling in and out of different time zones can affect your health, and offer tips on how to manage your diabetes through these changes.
Our bodies function like highly tuned machines. When it’s time to wake up in the morning, our body knows to release cortisol, a stress hormone. In ancient times, this stress hormone was vital in helping us escape a dangerous situation, but today, cortisol helps us get out of bed.
That release of cortisol triggers an increase in glucose (sugar) production by the liver. When this happens for people with diabetes, it creates a need for an increase in insulin to adjust glucose levels. “Optimally performing cortisol follows a pattern called the ‘cortisol curve’. In a healthy curve, cortisol is high in the morning and tapers off through the day and evening — like a slow-release energy pill that wears off just in time before going to sleep,” says functional medicine practitioner Sara Gottfried, MD.1
Once we are in a routine of waking up and going to bed around the same time each day, our bodies know when to release these stress hormones, and our diabetes medication has been timed accordingly. But when we experience a time change, our bodies can feel disoriented, especially that first week, and it may take some time to get back in balance.
Your body may need some time to adjust to a seasonal time change or change in time zones. However, “If your energy starts to run low during familiar activities, it could be a warning that your cortisol pattern is disrupted. Catching more colds or having mood swings more often and a shorter emotional fuse are other early signs,” says Filomena Trindade, MD, of the Institute for Functional Medicine.1 Talk to your healthcare team if you are experiencing any of these signs.
Daylight Savings Time (DST), known as British Summer Time (BST) in the UK, is done in many parts of the world where clocks are adjusted forwards in the spring and backwards in autumn to make better use of daylight. The time changes as part of daylight savings can disrupt sleep patterns,2 potentially affecting the delicate balance in your diabetes management and normal blood sugar levels.
In spring, many people around the world set their clocks forward, which means more sunlight and longer days ahead. But the first few weeks following this time change can be challenging. Losing an hour can make you feel a little drowsy over the next few days, not to mention that your glucose levels may be affected.
While gaining an extra hour of sleep in the autumn sounds fantastic, this time change can also affect people with diabetes. The shift might lead to changes in insulin requirements and timing, as well as fluctuations in blood glucose levels.4 You may sleep more, but there is also a potential adjustment period for diabetes management.
Have you ever noticed how a time zone change or daylight savings time can disrupt your morning routine? They certainly can, and when dealing with these adjustments, you’ll want to keep an eye out for the dawn phenomenon.
The dawn phenomenon, often referred to as the “morning rise” in blood sugar levels, is a notable factor in diabetes management. In type 2 diabetes, the body becomes even less sensitive to insulin, which leads to higher blood sugar levels in the morning. Blood glucose levels tend to increase from their lowest point during the night to the level right before breakfast.
To control the dawn phenomenon, it's important to find your own personalised solution with the help of your healthcare team. Solutions may include adjusting your diet, getting some extra exercise in the morning and evening, or considering taking medications.3
When you travel with diabetes, crossing time zones can be a bit more complex. Adjusting to a new time zone can disrupt meal and medication schedules, impacting your blood sugar levels. Because the body's internal clock can struggle to keep up with the time changes, diabetes management requires extra attention. This shouldn’t deter people with diabetes from enjoying travel, but rather serve as a reminder to plan ahead to carefully maintain glycaemic control.
Jet lag is another factor that can impact your glucose levels and sleep. Jet lag is a result of crossing multiple time zones,4 and disrupts your body's internal clock. Jet lag symptoms and effects increase based on the number of time zones crossed, especially when travelling eastbound. Changes in lighting, meal timing, and exposure to artificial light can contribute to fatigue, low mood, and sleep issues. To deal with jet lag symptoms and effects:5
● Drink plenty of water instead of alcoholic or caffeinated drinks.
● Eat the normal amount at your normal meal times.
● Stay awake while it’s still light out and try to sleep when it gets dark.
● Avoid artificial lights when possible.
Here are some key takeaways to help you navigate time zone changes and daylight savings time and their impact on diabetes and sleep:
How to set the time and date on your Accu-Chek Instant blood glucose meter.
This content is provided for general information only. It is not intended to amount to advice on which you should rely – you must obtain professional or specialist advice from your healthcare professional before taking, or refraining from, any action on the basis of the content. Although we make reasonable efforts to ensure that the content is up to date, Roche makes no representations, warranties or guarantees, whether expressed or implied, that the content is accurate, complete, up-to-date or that it should be relied upon.
NP-IE-00599 August 2026