June 8, 2017

Artificial Light is Making us Fat.


In the 1893 Chicago World Fair, Nikola Tesla lit 100,000 Westinghouse light bulbs and, like never before in history, night was turned into day.

That night in Chicago, dubbed the “city of lights,” started the race to light the world. Thus began the endless summer of artificial light. Electric lighting slowly filled houses, offices, towns, cities, and nations. Now, the entire developed world is dependent on artificial light. (1)

The “Endless Summer Effect.”

Before artificial light, in the winter, it would be dark in one’s home by 6 p.m. Today, lights don’t go off until 10 or 11 p.m.—or even later. As far as our circadian clock goes, these post-sunset, artificially-lit evenings add some two to five hours of extended daylight each day year-round—adding up to more than 1,000 hours of artificial light each year.

In nature, as a result of millions of years of evolution, every cell in the human body is hardwired to make major light/dark cycle shifts. As the sun sets, cortisol is replaced with melatonin. The sun’s blue light at sunrise suppresses melatonin and triggers the release of the adrenal hormone, cortisol. (2)

The long days and short nights of summer are followed up with winter’s short days and long nights, and our melatonin and cortisol levels adapt accordingly. The short days of winter send an evolutionary message that it is going to get dark and cold, and food will be scarce until late spring. The long days of summer send a message to prepare for winter by storing as much energy as possible to weather the long winter.

Summer has sent the message to feast before the famine of winter for some three million years. Early humans would gorge themselves on fruits, nuts, seeds, grasses, and tubers each summer when they were ripe, loading up on foods rich in carbohydrates and fats to feast on in preparation for the winter famine.

The strong cravings for carbohydrates in the summer is a natural circadian response to prepare for the famine, or lack of food, during the darkness of winter.

When we light our homes for an extra five or six hours after sunset, we are sending the “endless summer” message to our cellular biological clocks that it is time to crave carbohydrates in preparation for the famine of winter.

With artificial lighting and blue light emitted from our electronics, this carb craving can last for 365 days a year.

Sugar, the most concentrated form of carbohydrate, was only available at one time of year—the end of summer, before the onset of winter. From the perspective of an ancestral diet, it would be impossible to get these sugary carbs such as fruits, potatoes, and ripe grains at any other time of year.

The excess carbohydrates are stored as fat in the body—as a layer of needed insulation and energy reserve for the winter. Living with hours of artificial light reinforces our natural inclination to gorge on sweets.

Ever since the first taste of mother’s milk, humans have been conditioned to crave sweets. In fact, we still only have one taste bud for the sweet taste, and have over 300 and counting for the taste of bitter.

Bitter foods, like dandelion, could heal you, while other bitter foods can be poisonous. As a result, we have hybridized most foods to become sweeter.

The combination of artificial light at night, and an instinctual desire for the sweet taste, has been the perfect storm for chronic disease.

10 Tips to Combat the Endless Summer Effect, Sugar Addiction, and Melatonin Imbalance. 

>> Go to bed two hours after sunset, year-round.

>> Turn off computers, televisions, and cell phones before bed—or get a blue light filter for your devices.

>> When you wake, go outside and allow the morning sun’s rays to bathe your body for up to 10 minutes—even through a window is okay.

>> Make sure there is no ambient or LED light in your bedroom while you sleep.

>> Turn off the wi-fi while you sleep at night.

>> Stop eating foods with added sugars or sweeteners.

>> Eat whole foods and avoid packaged foods.

>> Try to fast for 13 hours from supper to breakfast each day.

>> Eat two to three meals a day and avoid snacking.

>> Start your day with a morning meditation—preferably with the morning sun’s rays on your skin.



1. T.S Wiley. Lights Out, Sleep, Sugar, and Survival. Atria Books, New York. 2000

2. Reiter R. Melatonin. Breakthrough Discoveries That Can help You Combat Aging, Boost your Immune System, Reduce the Risk of Cancer and Heart Disease and Get a better Night’s Sleep. Bantam Books, New York. 1995


Author: Dr. John Douillard
Image: Sunlight Cardigan/Flickr
Editor: Lieselle Davidson

Leave a Thoughtful Comment

Read 0 comments and reply

Top Contributors Latest

Dr. John Douillard  |  Contribution: 29,620