A recent study published in Proceedings of the National Academy of Sciences found that mice exposed to dim and bright light at night gained more weight than those not exposed to the light despite having the same physical activity and being fed the exact same amount of food. Per the article, 'Dim light-exposed mice ate 55.5% of their food during bright-light hours compared with 36.5% among those on a normal light-dark cycle. This level of daytime food consumption correlated with body mass and impaired glucose tolerance (both P<0.01). A second experiment in which food was only available during certain times showed that putting food out only during the normal nighttime eating hours prevented the excess weight gain and fat gain associated with dim light exposure'.
These finding implicate the disruption of circadian rythem as yet another possible contributor to obesity. Remember, obesity in and of itself, is a risk factor for many different cancers (pancreatic, breast, ovarian, prostate...to name a few) as well as multiple cardiovascular disease (heart attacks, stroke, etc). I recently read
another article (see below) that showed that sleeping 8-9 hours a night burned more calories and led to lower BMIs (body-mass index, a weight to height ratio) than sleeping 4-5 hours at night. So, obviously, uninterrupted sleep in a dark environment appears to be an important piece of the obesity puzzle. See the link below for a more detailed
summary of the article.
Dr. Maltz earned a Medical Degree and Master in Public Health from the University of Texas Medical Branch (UTMB) in Galveston, TX. She completed a combined Internal and Preventive Medicine Residency at UTMB in June, 2011. She then completed a 2-year Integrative Medicine Fellowship at Stamford Hospital in Stamford, CT, during which she simultaneously underwent an intensive 1000-hour curriculum created by The University of Arizona Integrative Medicine Program founded by Dr. Andrew Weil.