Bright Light At Night Causes Weight Gain
Exposure to bright light at night alters metabolism, increasing the risk of obesity and type 2 diabetes. We live in a very bright world. Most of us spend a lot of time indoors, with artificial lighting, plus we look at screens that emit a lot of blue light. A new study published in the journal Plos One has found this could be causing metabolic problems.
Scientists found that bright light exposure in the morning or evening increased insulin resistance compared to dim light exposure. Bright light in the evening also caused higher blood sugar levels. Insulin resistance is also called syndrome X. It refers to the body’s inability to adequately remove glucose from the bloodstream, causing an eventual build-up of blood sugar. Over time, the excess insulin and blood sugar could result in weight gain, fatty liver and a higher risk of type 2 diabetes.
Earlier studies showed that people who were exposed to the majority of their bright light in the morning weighed less than people who were exposed to most after 12 p.m. Earlier rodent studies also showed that mice kept in constant bright light developed altered glucose metabolism and gained weight compared to control mice that were allowed to sleep in the dark.
The researchers of this recent study have said “Our findings show that insulin was unable to acutely bring glucose levels back to a baseline level following a meal with bright light exposure in the evening. The results of this study emphasize that our lighting environment impacts our health outcomes.”
Many different factors affect a person’s body weight; it’s not only about how much you eat and how much exercise you do. Your exposure to bright light can alter your metabolism in such a way that healthy eating doesn’t enable you to lose weight. A lot of people stare at a screen that emits bright light in the evening: cell phones, ipads, tablets, computers and televisions. A lot of people look at their phone last thing at night before falling asleep. This not only disrupts melatonin secretion and reduces sleep quality; it can raise your risk of weight gain and type 2 diabetes. This finding may also help to explain why people who do shift work experience more difficulties losing weight. Bright light at night is unavoidable in those circumstances.
Perhaps a candle lit dinner, and reading a novel before falling sleep are healthier habits. You do also have the option of purchasing blue light blocking glasses, which can be worn after sunset when staring at a bright screen. This is just one little known factor that can stand in the way of weight loss. To find out about others, see the book I Can’t Lose Weight and I Don’t Know Why.
The above statements have not been evaluated by the FDA and are not intended to diagnose, treat or cure any disease.