The sleep diet — an idea whose time has come
For a lot of people, resolving to lose weight in the New Year translates into a lot of early mornings.
Some get up before dawn to get a run in while the city streets are still empty. Others want to get started on their daily juicing regimen and/or get a jump on the meal planning and packing up the day’s carefully portioned lunch.
Developments in the science of sleep, however, suggest that, instead, hitting the snooze button might be one of the most important tools we have for actually cutting back our calorie intake. Finally, a lifestyle intervention for slackers that involves calling it early, sleeping in, and, of course, plenty of late-morning and mid-afternoon naps.
The Sleep Diet — an idea whose time has come.
The past few years have seen a lot of peer-reviewed research fleshing out the sleep-diet connection and, at this point, there’s really no doubt that not getting enough sleep is a serious risk factor for obesity. And, now, studies working the reverse angle — that sleep might actually help people lose weight — are starting to emerge.
One study published in the “American Journal of Clinical Nutrition” found that sleep extension in research subjects was associated with reduced “free sugar” intake (sugar added to any food or drink, as opposed to natural sugars) by over nine grams per day.
“We started with people who weren’t sleeping enough and taught them to sleep more,” explains lead researcher Haya Al Khatib, nutritional scientist and guest lecturer at London, England’s King’s College. “Our primary objective was to see if is it possible to get people to sleep more but we also collected diet data. We found that, yes, it is possible to get people to achieve more and better sleep, but also found that people who slept more tended to eat less sugar.”
Al Khatib cautions that it was a small study that wasn’t really “powered” to collect all of the diet data. The first order of business had been to establish that you could help people get more rest, which they did thanks to “sleep hygiene” — consistent eating and bedtime schedules; making the room dark and getting rid of all electronic devices, including the television, from the bedroom. Other research is planned to see if the quality of our sleep can affect more than just sugar consumption.
A decreased sugar intake wouldn’t have been a huge surprise to anyone closely following the emerging field of sleep research, given how much we now know about the correlation between poor sleep and heart disease, diabetes, depression and certain cancers.
“Sleep is incredibly powerful, specifically when it comes to risk for overweight and obesity,” says Greg Wells, Toronto-area author and performance physiologist. “And we know that, when we sleep, we regulate two specific hormones, leptin and ghrelin, that control our appetite and satiety—how full we feel. When you get a good night’s sleep, those hormones are regulated and that enables you to make good decisions around food.”
Leptin reduces our appetite; ghrelin increases it. If these “hunger hormones,” (sometimes called “starvation” hormones) are out of whack, they send a signal to tell our brains that we are starving, which causes us to experience intense cravings for sugar and high-fat food. Wells says the signals can be so powerful that they make our food choices essentially completely out of our control.
That’s easy to understand on an intuitive level. Most days, my breakfast is berries and pecans, which I eat after my daily espresso (no dairy, no sugar). None recently, but back when I used to go places, if I had a super-early flight, I’d make a bee-line for the first Starbucks after the security gate, to order the fattiest breakfast sandwich available and a giant frothy beverage with all of the sugar packets.
Al Khatib says that, since sleep and diet is an emerging field, the precise mechanisms aren’t all fleshed out yet and there are still several hypotheses as to why we compensate for lost sleep with high-calorie food, but that we should probably also factor in stress.
“If you’re not sleeping enough, you’re less resilient to stress the next day and, when you’re more stressed, that impacts your eating habits,” she explains. “So, it’s not just about food, it’s our stress levels, energy levels and our ability to move around the next day because you probably won’t exercise.”
And that all will lead to a poor night’s sleep, since exercise will help you get a good night’s rest and fatty food will do the exact opposite. It’s sort of like the shame spiral from “The Simpsons,” except for sleep or, as Wells refers to it, “the ripple effect.”
“If you eat foods that are hard to digest, then your digestive system is going to be working all night and it’s going to make it harder for you to sleep deeply,” says Wells. “So very high-fat and very high-protein meals have been shown to negatively affect your sleep.”
Aside from eating a light supper, what can you do to avoid negative sleep-diet ripple effects? Sleep hygiene is pretty straightforward. Stick to a regular schedule, exercise regularly and eat earlier in the evening so you give your body plenty of time to digest before bed.
Also, stop answering emails in bed at the end of the night — don’t even bring the laptop in with you. You don’t want to think about tomorrow’s challenges at work when you’re trying to drift off. As well, the blue light emitted from our screens interferes with our melatonin production (another hormone, but one that regulates sleep). Experts recommend starting to power-down all screens a couple of hours before bed, so your melatonin can get to work.
Since that’s prime Netflix bingeing hour, that’s a tough one. Getting a good night’s sleep is well worth it, though. Not only does it feel great, it may well turn out to be one of the most important resolutions you can make this year to help you be more healthy, get more fit and possibly even lose weight.
Plus going to bed is a lot more appetizing than green juice in the morning — at least to my mind.
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What do you think about the sleep diet? Would you try it?