Im going to summarizing someone else’s summary on this one, but its a science heavy subject, the jargon gets in the way of the significance. 

-Firstly, credit to Bill Lagakos of Calories Proper. He always has great research and insights

So, if you’ve been on this list awhile, you’ve heard me talk about the human body evolved to with the day/night cycle. This is well-established science. Our bodies are basically evolved to wake up when its light outside, and we get tired when its starts to get dark. 

Simple enough. 

Now, let’s pose a question:

What happens when your day and night cycle become disrupted because of artificial light? 

Say you work in the stereotypical office setting. You are under fluorescent lights. Say you stay up late and watch TV, are on a laptop computer. Do these things affect you? 

Apparently, they do. A LOT. 

Specifically, they make you significantly fatter. 

Amazingly enough, this effect happens INDEPENDENTLY of calorie intake. Meaning you could have a clone, and you and your clone could eat 2,600 calories a day, and both exercise the exact same amount with the exact same day. 

BUT, if you stay up late all the time and are constantly being exposed to man-made light, and your clone does NOT do this,

you will be fatter. 

This might seem absurd, but the research done on light exposure has supported this happening. 

Basically what happens, the artificial light does not just make you stay up later, its affecting your entire hormonal cycle. And I mean ALL OF IT. Thyroid, insulin, serotonin, leptin, ghrelin, testosterone, estrogen, estradiol, progesterone, insulin, and so on and so forth. 

To be overly simplistic, a disrupted sleep cycle puts your body into more a “fat storing” state. 

The solution? I’ll quote Bill on this one

-don’t go into a caloric deficit or try to lose weight until AFTER you’ve done everything possible to improve circadian rhythms —
– get plenty of sleep
-don’t skip or delay breakfast in the morning,
-wear blue blockers at night, sunlight all day (or a bright light device if necessary). 

>>If these boxes aren’t checked PRIOR TO your weight loss efforts, then more muscle and less fat is lost; so even if you start paying attention to circadian rhythms later in the game, you’re already significantly handicapped.


So yeah, what Bill said.