We moved to daylight saving time – most of us treat it as a technical matter, but there are studies that indicate that this change, seemingly small, may affect our health and even our weight. So what is the connection between a change in the clock and a change in weight?
Less sleep = more cravings for carbohydrates. One of the first things that happens during the transition to daylight saving time is the loss of about an hour of sleep, at least in the first few days. The body is used to a certain time of sleep and waking – and when this habit is broken, we may feel more tired.
And why is this important? Studies show that fatigue impairs the brain’s ability to make good nutritional decisions, and increases the desire for sweet, calorie-dense or processed food. For example, a study published in "Sleep" found that sleep deprivation of even one hour per night causes an increase in calorie consumption the next day – mainly in the form of sweet snacks and simple carbohydrates. The explanation: The body is looking for a quick "boost" of energy, and sugar provides this immediately.
More light – more activity? Or more temptations? Daylight saving time extends the hours of light – and this sounds positive. Natural light encourages going outside, physical activity, and social gatherings. But – it is also important to remember the opposite effect: In a study conducted at the University of Minnesota it was found that more daylight hours do indeed increase the likelihood of going out for activity, but are also associated with an increase in food consumption outside the home – restaurants, ice cream, bars, picnics... and those calories – accumulate. In addition, more light in the evening may cause us to go to sleep later, and harm sleep hours – which returns us to the cycle of fatigue and weight gain.
The body clock does not always synchronize: The transition to daylight saving time may confuse the biological clock system (the "circadian clock"). If you feel hungry at 20:00, and on the new clock it is already 21:00 – what do you do? Wait? Eat twice?
This disruption, even if temporary, may lead to eating at unusual hours or to excess calorie consumption until the body rebalances. A study published in "Current Biology" showed that our biological clock resists artificial changes in light and sleep timing – and adaptation can take days, sometimes even weeks. Yes yes because of one hour that is moved! During this period, there is confusion between the feeling of hunger and the actual time – which may lead to eating out of a "sense of time" and not out of real need.
What is preferable – daylight saving time or standard time? The debate over daylight saving time versus standard time is far from over – but in terms of nutrition and metabolic health, there are strong arguments in favor of daylight saving time:
- The hours of darkness in winter are associated with a decrease in serotonin secretion – a neurotransmitter that affects mood.
- A decrease in serotonin levels has been linked to an increase in cravings for carbohydrates and sweets – as a way to "encourage" mood.
- In winter we stay at home more – and there are more hours of boredom, snacking, and unconscious eating.
- A study published in "Appetite" found that spending more time at home, especially during short daylight periods, increases the risk of emotional eating and weight gain.
- The cold itself increases hunger – the body seeks to raise internal temperature, and one of the ways is by increasing energy consumption.
- Studies have found that environmental cold causes an increase in hunger-stimulating hormones such as ghrelin, especially among leaner people.
In conclusion: The transition to daylight saving time does indeed affect our biological clock, both in terms of intestinal activity, eating habits or hunger hours, but does not necessarily increase the risk of weight gain.
In many cases, more daylight hours and a more active lifestyle may help mindful eating, physical activity, and a more natural feeling of satiety.
But, and this is no less important – in the first days of the transition – pay attention:
- Do not give up on sleep.
- Avoid sweet compensation for fatigue.
- Listen to the body, and not only to the clock.
And as always – balance, listening to ourselves, and understanding environmental influences, are the best way to maintain both health, and weight.