Women risk weight gain from “lights” during sleep
Exposure to artificial light at night (ALAN) from any variety of sources, such as televisions or night lights, can cause minute weight gain which adds up over time, according to a five-year survey of some 44,000 US women. Data links females who slept with a light on to being 17% more likely to have gained up to 5kgs (11 pounds) or more during the study period. The correlation was unaffected even after controlling for sleep duration, diet, and physical activity.
Dale Sandler and Yong-Moon Park of the National Institute of Environmental Health Sciences in North Carolina, US,suggests that the brightness may suppress sleep-inducing melatonin and disrupt circadian rhythm and eating patterns.Other explanations include light as a “chronic stressor” that changes the release mechanism of stress hormones regulating food intake. Intense or high light exposure is also thought to reflect socioeconomic disadvantages and unhealthy lifestyle behaviours, which contributes to weight gain.
The findings maintain the advice of good sleep hygiene and avoidance of light/electronic devices before bedtime, according to Malcolm von Schantz, a Chronobiology Professor at UK’s University of Surrey.
Meanwhile, the study leads have urged specific, reduced ALAN interventions for tackling obesity, which is a difficult and worldwide public health concern.
