MedicalResearch.com Interview with: Lead author: Yong-Moon (“Mark”) Park, MD, PhD Postdoctoral fellow Epidemiology Branch National Institute of Environmental Health Sciences   Senior author: Dale P. Sandler, PhD Chief, Epidemiology Branch, National Institute of Environmental Health Sciences National Institutes of Health MedicalResearch.com: What is the background for this study?   Response: A few studies had suggested that exposure to artificial light while sleeping was associated with obesity. However, the previous studies were cross-sectional, so we really do not know which came first - exposure to artificial light while sleeping or obesity. Another problem was that previous studies did not fully account for other characteristics that could affect this association, such as sleep duration and quality, calorie intake and dietary patterns, and physical activity. We studied nearly 44,000 women ages 35-74 from across the US who are enrolled in the Sister Study cohort. Women had body weight characteristics measured at baseline and provided self-reported information on weight at baseline and follow-up – on average 5.7 years later. (more…)