How daylight changes affects the health

Academic research shows that losing an hour of daylight can be linked to negative effects on both the mind and body, including disturbed sleep patterns, seasonal depression and obesity.

Both the amount and quality of sleep have been shown to be important for mental and physical health, says Dr. Phyllis Zee, director of Northwestern Memorial Hospital’s Sleep Disorders Center in Illinois. “Disturbed sleep is associated with depression, memory and learning impairments, cardiovascular and metabolic disease risk factors (diabetes and heart disease), obesity, and impaired ability to fight infections.”

Even when clocks change backward or forward by just an hour, circadian misalignment — the difference between the timing of a person's natural internal clock and their required work or sleep/wake schedule — can occur, which Zee says “has been shown to increase risk for mood disorders, cardiovascular disease, diabetes, stroke and breast cancer.”