Optimising indoor lighting may help reduce the metabolic effects of prolonged indoor lighting exposure

According to a new Diabetologia study, obese, insulin-resistant adults' sleep energy expenditure is affected by the timing of light exposure.  Therefore, optimising indoor lighting more like natural light/dark cycle may help lessen negative impacts on whole-body energy and glucose metabolism.

A 24-hour cycle of light and dark is required to synchronise the body's circadian clock. Obesity and cardiovascular disease are connected to solid light exposure late at night or early in the morning. People are exposed to glare at home, at work, or via screens of electronic gadgets at night since modern light is widespread and available 24/7. Light at night (LAN) exposure is linked to an increased incidence of type 2 diabetes in the elderly.

The modern culture also lacks time spent in intense light during the day. In reality, most time is spent indoors, with artificial light levels far below natural daylight.

The study indicated that spending the day in bright light reduced blood glucose levels before dinner. Exposure to the dim day - bright evening condition reduced sleeping metabolic rate (SMR) and energy expenditure after the meal. This illumination cycle also decreased melatonin production, which should rise 2-4 hours before bedtime to reduce natural light levels.

The study reveals that insulin-resistant people's indoor light environment can change metabolic parameters time-dependent, affecting long-term metabolic health.