Your Personal Paleo Code: The 3-Step Plan to Lose Weight, Reverse Disease, and Stay Fit and Healthy for Life (26 page)
Authors: Chris Kresser
Tags: #Health & Fitness / Diet & Nutrition / Diets, #Health & Fitness / Diet & Nutrition / Weight Loss
Like me, like Terry, and like our Paleo ancestors who walked, ran, and simply moved throughout their day for basic survival, you can easily incorporate movement into your daily routine. It will make your life better—and probably longer.
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Stand for half of your day.
•
Take a standing break every thirty to forty-five minutes.
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Aim for walking ten thousand steps a day.
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Integrate as much light activity into your day as possible.
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Aim for 150 minutes of moderate-intensity activity per week, or 75 minutes of vigorous activity per week, or 30 sets of highest-intensity activity per week, or some combination of the above.
Notes for this chapter may be found at ChrisKresser.com/ppcnotes/#ch12.
Sleep More Deeply
Sleep Quiz
Complete the quiz below and use the answer key to determine your sleep score.
I have not been diagnosed with a sleep disorder, such as sleep apnea
Points
: 1
I regularly sleep more than eight hours per night.
Points
: 2
I rarely feel sleepy or struggle to remain alert during the day.
Points
: 1
I rarely have difficulty falling asleep.
Points
: 2
I rarely wake up earlier in the morning than I would like to.
Points
: 1
I never have thoughts racing through my mind, preventing me from getting to sleep.
Points
: 1
I rarely have trouble concentrating at work or school.
Points
: 1
I have never fallen asleep while driving.
Points
: 1
I almost never doze off while watching TV, reading, or sitting in a car.
Points
: 1
I have never been told that I snore.
Points
: 1
I do not expect a problem with sleep during the week.
Points
: 1
I feel full of energy.
Points
: 1
It is easy for me to get up in the morning.
Points
: 2
I do not experience vivid dreams or hallucinations upon falling asleep or awakening.
Points
: 1
After taking a nap, I feel refreshed.
Points
: 1
I have never worked in a job that involves shift work or night work.
Points
: 1
I rarely travel across times zones (east-to-west travel).
Points
: 1
I rarely use an electronic device with a screen (TV, laptop, cellphone, iPad) within one hour of going to sleep.
Points
: 1
My sleep environment is quite (or completely) dark.
Points
: 1
I feel that the quality of my sleep is satisfactory.
Points
: 1
TOTAL
Give yourself the correct number of points to all of the questions you answered yes to. Then use the information below to determine your sleep score.
Total Points
: 7+
What Your Points Mean
: You are likely getting an adequate amount of sleep during the week.
Your Personal Paleo Code
: Complete the
Your Personal Paleo Code
3-Step program. No additional personalization is required.
Total Points
: 4–6
What Your Points Mean
: You’re probably not getting enough sleep, or the quality of your sleep is poor.
Your Personal Paleo Code
: Complete the
Your Personal Paleo Code
3-Step program and add the recommendations in this chapter.
Total Points
: 0–3
What Your Points Mean
: You may be experiencing a sleep disorder or very low-quality sleep.
Your Personal Paleo Code
: Complete both steps above and see a health-care provider for additional assistance. This should be a major focus for you, and ignoring this area may stand in the way of improvement elsewhere.
There are few things more important to health than a good night’s sleep. A large body of evidence suggests that most people require seven to nine hours of sleep each night for optimal function and prevention of disease. But an increasing number of people in industrialized countries are falling far short of this ideal. According to data from the National Health Interview Survey, approximately one-third (35 percent) of U.S. adults sleep fewer than six hours a night. This may not seem unusual today, but it’s a relatively recent phenomenon: just fifty years ago, only 2 percent of Americans averaged fewer than six hours of sleep a night. During that period, American adults and adolescents lost between one and a half to two hours of sleep a night, and chronic sleep loss and sleep disorders are now estimated to affect seventy million Americans. The consequences of chronic sleep deprivation are nothing short of catastrophic. The sleep-wake cycle—an important part of the twenty-four-hour biological clock known as the circadian rhythm—affects nearly every aspect of human physiology, including brain-wave patterns, hormone production, cell regulation, immune function, and metabolism. In fact, studies suggest that the circadian cycle controls from 10 to 15 percent of our species’ genes. This may explain why disruption of the sleep-wake cycle is associated with numerous health issues, such as depression, obesity, memory loss, type 2 diabetes, and cardiovascular disease, as well as an increased risk of death.
Perhaps not surprisingly, understanding of the negative impacts of sleep deprivation has increased during the very period that sleep duration
has decreased so precipitously. We’re effectively engaged in a giant, society-wide experiment using ourselves and our children as test subjects, and so far the results are not encouraging. Despite current attitudes (“I’ll sleep when I’m dead”), sleep is not optional. It’s crucial to the proper function of every system of the body, and we can’t escape the consequences of getting too little of it. Improving the quality, duration, and timing of your sleep is one of the single most powerful interventions you can make to improve your health.
The prevailing theme of this book is that human beings are biologically adapted and genetically designed for a particular diet and lifestyle and that we are currently mismatched with our current environment. This is as true for sleep behavior as it is for diet and physical activity. For the vast majority of humans’ evolutionary history, our species lived in harmony with natural rhythms of day and night, without exposure to artificial light. They were active during the day and rested at night; they did not have ready access to stimulants like caffeine and tobacco; and they didn’t have cell phones, computers, tablets, video games, and other electronic devices. Today, these influences are ubiquitous—and their effects are profound. They include:
•
Light pollution (excess artificial light):
Artificial light has many benefits—such as increasing productivity and making recreational activities possible at night—but it hasn’t come without a cost. Exposure to artificial light at night affects circadian rhythms (along with nearly every other aspect of human physiology) and shifts the natural biological clock. It does this primarily by suppressing the production of melatonin, an important hormone that helps regulate the sleep-wake cycle and plays a role in numerous other biological functions.
•
Electronic media use:
Electronic media—including television, computers, tablets, mobile phones, and video games—is another relatively new phenomenon that has become ubiquitous in modern society. Too much electronic media use at night has been shown to interfere with getting a good night’s sleep.
•
Changes in work habits:
Work is the primary activity exchanged for sleep, and work hours in the United States have been steadily increasing over the past several decades. But it’s not just how much we work that is eating into our sleep time; it’s the way we work. Twenty percent of the population in industrialized countries now work beyond the normal hours in various types of shift work or flexible work schedules, and thanks to cell phones, laptops, and the Internet, the barriers that previously separated work and leisure time have dissolved.
•
Jet lag:
Jet lag is another modern phenomenon that affects the natural rhythms of the circadian clock. Chronic jet lag—which is associated with regular travel across time zones—has been shown to decrease sleep quality, reduce cognitive function, raise cortisol levels (a sign of stress), and even increase the risk of cancer (due to disturbances of melatonin levels).
•
Other aspects of the modern lifestyle:
Physical inactivity, excess alcohol consumption, illicit-drug use, cigarette smoking, and caffeine are all associated with decreased sleep duration and quality.
Now you know how much less people are sleeping and why, but what, exactly, does chronic sleep deprivation do?
Changes in sleep duration and quality increase the risk of everything from heart disease to diabetes to overall mortality; there’s little doubt that sleep loss is directly contributing to the modern epidemic of chronic inflammatory disease.
Let’s examine the effects of poor sleep on three particular areas in more detail.
Cardiometabolic disease refers collectively to diabetes, cardiovascular disease, and obesity. It is by far the most common cause of death and disability worldwide in industrialized countries. While most people are aware of the connection between lifestyle factors like diet and physical activity and cardiometabolic disease, the contribution of chronic sleep deprivation is less well known.
This is already changing, though, since numerous scientific studies have shown that sleep loss directly affects cardiovascular and metabolic function in several ways:
•
A single night of partial sleep deprivation causes insulin resistance even in healthy subjects with no preexisting metabolic disease. Exposure to even low levels of artificial light at night may contribute to weight gain by promoting late-night snacking and disrupting metabolic signals.
•
A randomized controlled trial with 225 participants found that restricting sleep over five consecutive nights led to increased calorie intake (especially late at night) and weight gain.
The effects of sleep deprivation on food intake alone could almost single-handedly explain the connection observed between obesity and impaired sleep. One study showed that restricting sleep for eight consecutive days increased subjects’ calorie intake by 566 calories per day, with no changes in energy expenditure. Imagine this pattern over the long term: Eating an extra five hundred calories a day with no changes in how many calories you burn is equivalent to gaining a pound a week, or fifty-two pounds in one year! But the connection between sleep and obesity goes both ways: obesity has been shown to worsen sleep quality, usually due to a higher prevalence of sleep disorders such as sleep apnea.
Jen, twenty-eight, came to see me complaining of difficulty reaching her target weight. She had started a Paleo diet nine months prior to our visit, and she lost twenty-five pounds—almost all of the thirty pounds she wanted to lose—over the first five months. But no matter what dietary modifications she made, Jen couldn’t lose those final five pounds. “It’s so frustrating,” Jen told me. “I’m eating perfectly and exercising every day, but nothing changes. I’m completely stuck.”
I reviewed Jen’s case history, and I noticed she had a habit of staying up until midnight or later. She often used her laptop or iPad at night to check e-mail or chat with her friends on Facebook. She woke up frequently through the night and sometimes had trouble falling back asleep. And though she was often in bed for eight hours, she woke up feeling unrefreshed. I suggested to Jen that inadequate sleep and too much exposure to artificial light at night might be disrupting her metabolism and preventing her from losing those last five pounds. I suggested she try:
•
Getting to bed by ten or ten thirty each night
•
Stopping electronic media use at least two (and preferably three) hours before bedtime
•
Wearing orange glasses that filter out melatonin-suppressing blue light after dark (see below for more on this)
•
Making her sleep environment pitch-dark, cool, quiet, and free of electronic devices (Jen had a habit of leaving her phone on the nightstand)
•
Getting exposure to natural light first thing in the morning by taking a fifteen-to twenty-minute walk outside
After making these simple changes, Jen the found the quality of her sleep improved dramatically, and she was finally able to lose those last five pounds. “I have so much more energy when I wake up,” she reported, “and I feel much calmer throughout the day. But the best part is that I don’t feel hungry all the time anymore, and I’ve lost the extra weight without even trying.”
Disrupted circadian rhythms and chronic sleep loss alter immune responses, leading to an increased risk of cancer, greater susceptibility to infection, and more inflammation. Melatonin plays a key role in the inhibition of cancer development and growth and the enhancement of immune function. In a remarkable study at Johns Hopkins University, researchers injected two groups of mice with a known cancer-causing agent. Then they exposed one group to sixteen hours of daylight and the other to sixteen hours of darkness. The rats in the group that experienced darkness had melatonin levels significantly higher than the other group’s, and not a single animal developed cancer. However, in the group that was exposed to light, 90 percent of the animals developed cancerous tumors. The authors of the study speculated that adequate periods of darkness each day and seasonally throughout the year were necessary for proper immune function. Human studies have found similar results. People who are exposed to light at night on a regular basis (such as shift workers or those who stay up late using the computer or playing games) experience melatonin suppression and are at higher risk of developing several different types of cancer, including breast, colon, prostate, and endometrial cancer, as well as influenza and chronic infections.