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Examining the Association Between Artificial Light at Night Exposure & Obesity

August 2020



Animal studies have shown that there is an association with exposure to artificial light at night (ALAN) and disturbances in melatonin signaling, sleep disruption, and circadian rhythms, which could result in weight gain and obesity. The close association with the implementation of artificial light and the rise in obesity may have a causal connection or may be a stronger contributor. Up to this point limited studies have been done to explore the association between ALAN and obesity in humans.

Methods: An exhaustive search of available medical literature was performed by two parties, independently of each other. Databases searched were MEDLINE-PubMed, TRIP, Web Science, and CINAHL. The following search terms were used: obesity, artificial light, ALAN, LAN, sleep, night and weight gain. The bibliographies from relevant articles were also searched. Other inclusion criteria required human specific studies. Included for background information were studies conducted on model organisms looking at the effects of ALAN. Studies were excluded if they did not address the question. Risk of bias for each study was evaluated using JAMA evidence critical appraisal worksheets.

The initial search yielded 105 articles. After eliminating duplicates and screening these results for relevant articles using eligibility criteria, there were a total of 2 articles. These articles were 2 prospective analysis studies. Almost all other studies/articles had to do with model organisms and not the specific eligibility criteria.

These two prospective studies are the first to look at the potential effects and significance of ALAN in the human population. They reinforce what has been identified in model organisms, showing that there is a relationship to weight gain with artificial nighttime light exposure. These studies also aid in identifying contributory factors that warrant further investigation and research to better understand the underlying causes of the obesity epidemic.

Keywords: Obesity, Artificial Light, ALAN, LAN, Sleep, Night and Weight Gain


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27 May 2020
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