During the 9-day Lunar New Year holiday, many people's first choice for the break was not to travel but to sleep in to make up for the fatigue accumulated from early mornings and overtime work. However, endocrinologist Wang Lu-ting (王律婷) warns that this choice may actually make you feel more tired.

Wang explains that international research defines a shift of more than 1.5 hours between the "midpoint" of sleep time between weekdays and weekends as "social jet lag." For example, if you go to bed at midnight and wake up at 7 a.m. on a weekday, your sleep midpoint is 3:30 a.m.; but if you go to bed at 2 a.m. and wake up at noon on a weekend, your sleep midpoint shifts to 7 a.m., creating a social time difference of 3.5 hours.

She details the body’s responses to this social jet lag, saying that, "The first is a change in gut microbiota, and the second is the inflammatory response. Even if you get enough sleep, if the timing is wrong, the number of harmful bacteria in your gut will increase. This time difference will also raise inflammation levels in the body, and if this state becomes chronic, you will feel tired and lack energy."

Wang stated that this sleep difference can also disrupt the central nervous system, dulling the brain's reward mechanism responsible for feelings of pleasure, leading to reward-seeking behavior, such as strong cravings for foods with higher sugar and fat content. She further pointed out that because men are more sensitive to hormonal changes, systemic chronic inflammation is more pronounced in men than in women. Furthermore, children and adolescents are more prone to the effects of social jet lag.

Rest should not be about excessive sleeping, Wang said, instead suggesting three principles for catching up on sleep that won't harm your health: keep your sleep midpoint time within 1.5 hours, stick to 20-30 minutes for afternoon naps, and gradually adjust your schedule 2-3 days before returning to work. This not only allows you to avoid feeling more tired, but also makes you less likely to experience post-holiday blues.