To sleep, perchance to slim: Low carb and Paleo diet gurus explain sleep-weight loss links
By Joanne Eglash on July 01, 2014
"To sleep, perchance to shed pounds; Aye, there's the rub." With apologies to William Shakespeare's "Hamlet," that sums up the intriguing connection that's become evident between our slumber and our weight. How can you make the latest information work for you? I asked some of the world's weight loss experts to share their knowledge.
Paleo diet expert Robb Wolf is the author of "The Paleo Solution: The Original Human Diet." But a Paleo lifestyle doesn't stop with the food you put in your body. A truly Primal lifestyle enhances your sleep as well.
This is why we like to call the paleo concept a "template" as it is much more than just dietary guidelines. When we look at evolutionary biology, we can gain deep insight into a host of modern health concerns based on how our gene/environment interaction has changed so dramatically in the past few thousand years," Robb told me.
Moreover, there's a link between Paleo low carb diets, which lower inflammation and stabilize blood sugar levels, and the quality and quantity of your sleep.
"Inflammation or blood sugar swings are a stress on the body," explained Robb. That causes our bodies to release cortisol. And while that hormone is helpful when we're dealing with fight-or-flight situations short-term, the long-term impact can cause problems, particularly if cortisol levels are high at night.
In addition, our bodies are bewildered by a concept called circadian rhythms. We wake up and head to work under bright artificial lights coupled with glaring computer screens while avoiding the natural light shifts from dawn to dusk outdoors. We then head home and indoors to watch TV/look at the cell phone screen/stare at the computer under more bright lights.
Two problems result, says Robb. "We do not get enough INTENSE light during the day as we tend to work inside, but then we also tend to have far too much light in the evening when, again from an evolutionary perspective, light levels would have been quite low. Intense light during the day tends to "anchor" our normal rhythm as the light from the sun sends signals to the brain about what part of the day we are in."
Both the daytime lack of intense light and evening relatively intense light "interferes with both melatonin production ( a neurotransmitter critical for sleep initiation) and cortisol levels."
Solution: Dim your evening lighting. And "as goofy as it sounds, wear some kind of red tinted glasses to block the blue and green wavelengths of light entering the eye as it is these wavelengths which tend to suppress melatonin production the most." Just one caution: Don't block light and drive - Robb notes that "the company that makes BlueBlocker sunglasses were actually sued as they were so effective at screening out blue and green light that folks were falling asleep while driving."
As for weight loss vis a vis caloric intake at meals? "Some people tend to sleep better having eaten a small meal in the evening, other do better with a large meal." That might also change based on the season, since enormous steaks late at night might not help you sleep when it's 91 degrees outside.
And, emphasizes Robb, "although the paleo template provides a fantastic framework to look at problems like insomnia and weight loss it's important to put customization to the individual above any type of theory." For guidance on customizing the Paleo plan, read "Your Personal Paleo Code: The 3-Step Plan to Lose Weight, Reverse Disease, and Stay Fit and Healthy for Life."
As he points out, our ancestors may have had to cope with lions and tigers and bears (not to mention a dinosaur or two), but they didn't suffer from "over-exposure to artificial light at night from smart phones, tablets, computer monitors, etc (eg, The incredible camping experiment). Furthermore, our indoor lifestyle deprives us of morning bright light exposure from the sun. These daily events (exposure to bright light in the morning and absence of bright light in the evening) are critical to maintaining healthy circadian rhythms which is important not only for sleep quality, but also reducing the risk of diseases such as metabolic syndrome, obesity, cardiovascular disease, and cancer. "
As for the link between sleep and weight loss? It is most certainly so, says this expert.
"Circadian disruptions can most certainly predispose to weight gain, and can sabotage weight loss programs. For example, poor sleep quality has been associated with obesity in numerous studies (eg, Depner et al., 2014). And one recent study in over 100,000 women showed that exposure to excess artificial light at night was associated with a statistically significantly increased risk of obesity, independent of other risk factors such as physical activity (McFadden et al., 2014)."
Moreover, in what Dr. Lagakos considers a seminal study, "researchers showed that participants subjected to reduced sleep time (5.5 vs. 8.5 hours) lost significantly less fat mass and more lean body mass relative to those allowed to sleep longer (Nedeltcheva et al., 2010, discussed further here). This is of critical importance because body composition, not body weight per se, is much more strongly associated with health and quality of life."
How about those sleep supplements that promise to send you off to dreamland?
"Melatonin may help some people while adapting to jet lag, although chronic use to offset circadian arrhythmia-induced insomnia will likely prove to be largely ineffective," he cautioned.
However: "That said, there are steps people can take which mimic the environmental conditions of our ancestors, to a degree. For example, bright light boxes emit a frequency of blue light which mimics an important aspect of sunlight, and when used in the early morning hours, they have been shown to improve: 1) daytime alertness; 2) nocturnal melatonin secretion; and 3) sleep quality (eg, Fiat lux)."
"Further, and likely just as important (if not more so), is blocking excess blue light exposure in the evenings. Numerous software programs have been developed which dim the screens of smart phones, tablets, and computer monitors. Also, eyewear with amber lenses, also known as ‘blue blockers,’ are very effective at this and have been shown to improve nocturnal melatonin secretion and sleep quality."
Anecdotal evidence: I've been wearing the Blue Blocking Driving Wayfarers Sunglasses not for driving (see Robb's caution) but in the evening. Although the cats dived under the bed in terror when I first put them on, they do work. (And the cats have now adjusted - my theory is they think it's just another Stupid Human Trick.)
And that saying to eat like a king or queen in the morning but nibble at night like Oliver Twist ("Please, sir, may I have some more gruel?") is true.
"Eating a large, carbohydrate-based meal at night is not ideal because melatonin and insulin exhibit an additive impact on fat tissue growth. Furthermore, a larger, protein-rich breakfast has been shown to reduce hunger levels and is associated with more favorable nutrient partitioning."
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