Tag Archive: cortisol


This is another post for notes and thoughts about the book “Lights Out: Sleep, Sugar, & Survival” by T.S. Wiley with Bent Formby, PhD.

I do feel I should note (since I didn’t say it yesterday but it does still apply), this info is from the book, not my opinion, not medical advice, and I have not at all verified the validity of this or looked at the research myself. (End disclaimer.)

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Chapter 3 Notes:

The chapter starts off by talking about how the bacteria in our digestive tract is a major player in our immune system & sleep. There’s some science here that I’ve heard before, so I’m not going to repeat it (I’d rather read than wrote today).

There are a few key points I want to note though:

* Body senses sugar/ stress–> produces cortisol.
Light–> elevates cortisol levels.
[Circadian rhythms + carbs] Control Insulin production.

* “Insulin secretion is controlled by the food you eat, but the food you want is controlled by your immune system responding to perceived seasonal variation in the light.” (p. 56)

* Lots of light = end of summer = need to bulk up and hibernate –>
“Carbohydrate craving is a precursor to sleep that we all still respond to every night that we’re up late…. Remember, a midnight snack is never a hard-boiled egg.” (p. 56)

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* “…the end of summer is the only time in actual nature you would ever have full stores and twenty extra pounds, which the long light and short nights have provided.” (pp. 59-60)
Because of the body’s feedback systems (leptin resistance),
“…your appetite for carbohydrates stays permanently switched on until all of the carbohydrates run out. This mechanism exists because in nature you would never get that fat unless you needed to, because all the food will be gone.
“The problem in the world we live in is that the food (sugar) will never be gone.” (p.60)

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* Protein/ fat/ carb use in the body & appetite for them are controlled by separate & distinct substances
“Carbohydrates are energy that can be stored, and they can only be stored by insulin. That’s why you can’t eat fat and get fat; but you do eat sugar and get fat.” (pp. 60-61)

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Chapter 4 Notes:

* Evolutionary biology is about how we adapt to survive in our ever-changing environment.
“Survival is having enough sugar to store some for when there is none available.
“Survival was never about eating fat, it was always about making fat.
“Survival, thy name is sugar.” (p. 63) (i.e. Carbohydrate)

* Insulin delivers sugar to cells & tells body to store the excess (as fat, which is lighter since carbs = fuel + water ).

* Prolactin controls appetite. It makes milk & stimulates mom’s immune system into overdrive so baby gets mom’s antibodies in the breast milk (along with a taste for sweet- milk is very high in carbs & adds bulk quickly which baby must have so as not to die of exposure).

It also supresses leptin, thereby controlling appetite throughout the lifespan.

In winter, melatonin keeps prolactin production to night, so we don’t crave sugar (bc it wouldn’t b available anyway), but in an “endless summer” prolactin secretion during day supresses leptin, makes us crave sugar, and stimulates our body’s autoimmune response (hence the so-called “diseases of civilisation” & allergies).

* Leptin is produced by body fat & is supposed to supress the sugar cravings.

* Last ice age changed our metabolism permanently. We had to live on protein & fat most of the year & fruit/ veggies only when in season (which is rare when the grounds are covered in ice/frost. Diet/lifestyle analysis (bone studies) show increased muscularity & height compared to modern humans.

*BONE STUDIES (Emory University anthropologists, as reported in “The Paleolithic Prescription”):

50,000 years ago, Eastern Mediterranean men averaged height of 6’2″ & avg. people were as muscular/ strong as today’s elite athletes– AND they were genetically indistinguishable from modern humans.

Agriculture showed up in human culture about 10,000 years ago, ending the Paleolithic period & starting the Neolithic period: the agriculturally-based lower-fat/ lower-protein/ higher carb (ie 90% carbs)/ disease-ridden period.

So (according to the books):

taming fire (endless summer) + agriculture (endless carbs) + technology/ tools (grinding grain stretches it further to feed more people) = obesity & sickness.

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This post is for notes and thoughts about the book “Lights Out: Sleep, Sugar, & Survival” by T.S. Wiley with Bent Formby, PhD.

Using evolutionary biology & biophysics, they posit that our sleep deficit (and the resulting hormone imbalance) is responsible for sugar cravings, obesity, and other “modern” diseases. I know I chronically feel tired, so I’m very interested right now in anything that will help me to feel healthier and release the stranglehold sugar has on my mind, body, and emotions.

According to them, “Sleeping controls eating, eating and stress control reproduction. Sleeping, eating, and making love control aging.” (p. 4)

They go on to say (after a bit of a conspiracy-theory type rant) the following:

“When we asked Dr Thomas Wehr, the head of the department studying seasonal and circadian rhythmicity at the NIH in Washington, whether he felt the public had a right to know that on less than 9.5 hours of sleep a night – i.e. in the dark – they will (a) never be able to stop eating sugar, smoking, drinking alcohol, and (b) most certainly develop one of the following conditions: diabetes, heart disease, cancer, infertility, mental illness, and/or premature aging, he said “Well, yes, they do have a right to know. They should be told; but it won’t change anything. Nobody will ever turn off the lights.”” (pp.5-6)

Interesting. I’ll let you know after I read more!

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Chapter One Notes:

* Exercise –> triggers cortisol release (fight or flight.. running=flight)
* Extended exposure to light (i.e. changing natural light/ dark cycles) makes the body think it’s summer, which in nature kicks on the ‘mate now & store fat for the upcoming winter famine’ instinct
* The interplay of high cortisol, artificially extended “daylight”, sugar consumption and insulin response = fatty bodies
* Fat = health; Sugar = disease (I think they’re Paleo)
* Common Opinion –> eat less fat, exercise more & you’ll be healthy; Reality –> people are mostly fatter & sicker

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More Ch. 1 Notes:
* Light & dark cycles govern prolactin & melatonin, which govern our immune systems
* Hyperinsulinemia – body’s chronic overproduction of insulin; only occurs with chronic high ingestion of carbs (impossible in nature, unless you lived somewhere that always had fruit/ veggies in season)
Insulin allows blood glucose into cells; insulin resistance means receptors no longer allow insulin to open them so no more glucose can enter the cells (protective mechanism)
“high insulin levels create the same state in the brain as alcohol does” (p.24)
“The spike of insulin after a binge [alcohol or sugar] makes the serotonin in the brain turn into melatonin and it’s lights out…. Sleep it off.” (p.24)

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Chapter Two Notes:

* Excess light at night suppresses Melatonin
* Melatonin naturally suppresses sex hormones (estrogen/ testosterone; because it’s safest to breed in summer so babies are born in spring when food is plentiful)
* Excess light at night –> excess insulin, estrogen, testosterone –> diseases and endocrine disorders