The Hidden Health Impact of Losing an Hour to Daylight Savings Time
While the arrival of British Summer Time brings longer evenings and outdoor celebrations, the annual spring clock change carries significant health implications that many overlook. Losing a single hour of sleep as clocks move forward can profoundly affect metabolism, hormone balance, and energy levels by disrupting the body's natural circadian rhythms.
Circadian Disruption and Social Jet Lag
Dr Jeffrey Kelu, a circadian rhythms expert at King's College London, emphasises that our internal body clocks, primarily synchronised by light exposure, regulate essential physiological functions like the sleep-wake cycle and metabolism. The acute effect of the spring clock change is a sudden reduction in sleep duration, caused by the overnight loss of one hour, and the difficulty in adapting to earlier wake times, he explains. This disruption can lead to chronic 'circadian misalignment', often termed 'social jet lag', which research links to increased risks of obesity, metabolic syndrome, and mood disorders.
The British Sleep Society has campaigned to abolish Daylight Savings Time globally to safeguard public health and wellbeing, highlighting the severity of these disruptions. Dietician Dr Sammie Gill notes that the digestive system also follows circadian rhythms, potentially causing 'gut lag' during the adjustment period. Generally, the spring clock change is considered more disruptive than the autumn change where you gain an hour of sleep, she says, adding that while most people adjust with assistance, individual adaptation rates vary.
Public Opinion and Practical Solutions
Britons remain divided on Daylight Savings Time, with a 2024 YouGov poll showing 46 per cent support it, while 42 per cent advocate for its abolition. Regardless of personal stance, experts recommend strategies to mitigate health impacts during the transition.
Shift Your Routine Gradually
Planning ahead is crucial. Ruth Taylor, a nutritionist at Boots Online Doctor, advises gradually adjusting schedules in the days before the change. Try to shift your bedtime, wake time, and mealtimes by 15 to 20 minutes earlier each day to help your body ease into the new schedule, she suggests. This maintains consistency with your body's internal clock rather than the abrupt shift in clock time.
Maintain Regular Meal Times
Once adjusted, stick to the routine. We thrive on routine, and even a one-hour change can mean we eat out of sync with our internal clock. This can affect blood sugar regulation, hormone balance, and our energy levels, Taylor explains. Keeping regular mealtimes, especially for breakfast, lunch, and dinner, aligns digestion and metabolism with circadian rhythms.
Prioritise Breakfast and Avoid Late Eating
Research indicates that aligning meal times with the body's readiness for food aids weight management, blood sugar balance, and heart health. Shifting breakfast by an hour can cause 'metabolic jet lag', disrupting these processes. Taylor recommends eating a nutritious breakfast within an hour or two of waking to kickstart metabolism. For evening meals, finish at least two to three hours before bedtime to avoid sleep disruption, opting for light, sleep-friendly snacks if necessary, such as Greek yoghurt with kiwi.
Manage Fluids and Light Exposure
Hydration is key, but reduce fluid intake close to bedtime to prevent nighttime awakenings. Limit caffeine consumption six to eight hours before sleep and minimise alcohol in the evening. To support circadian rhythms, get natural light exposure in the morning through activities like an early walk or sitting by a window. Exposing your eyes to natural light early in the day can promote melatonin balance, Taylor says. Conversely, minimise bright artificial light, especially from screens, in the evenings to improve sleep quality.
By implementing these small adjustments—from meal timing to light management—individuals can help their bodies adapt to the clock change, maintaining better sleep, digestion, and overall energy levels during British Summer Time.
