How Daylight Saving Time affects your sleep and diet As clocks spring forward in the northern hemisphere, many people will be looking forward to longer, sunnier evenings—a few groggy mornings is a price they’re probably willing to pay. But a growing body of research suggests that they ought to be more cautious. The arrival of Daylight Saving Time (DST) seems to have long-lasting negative effects on human health. The human body clock, known as the circadian rhythm, lives in a region of the brain’s hypothalamus known as the suprachiasmatic nucleus (SCN). It determines whether you feel awake or sleepy by regulating the production of melatonin, the sleepiness hormone, and cortisol, a stress hormone that promotes alertness. It is also essential for the timing of bodily functions, including the expression of genes and regulation of metabolism and mood. …