It's Official: Sleep Keeps You Fit
Skip 80 minutes of sleep tonight and you'll likely consume an average of 550 extra calories tomorrow, says a Mayo Clinic study from spring of this year.
550 calories is about the equivalent of a Big Mac. Or 2 servings of potato chips. Or a giant bakery muffin. Skip the sleep, slip up on the willpower and... BAM!
Two sleepless nights per week can add up to 16 pounds gained over the course of a year, all else being equal.
There are two hormones responsible for much of your appetite:
- leptin: responsible for long-term energy regulation; limits appetite and food consumption.
- ghrelin: fast-acting hormone; initiates feelings of hunger.
Both leptin and ghrelin respond to how well-fed you are, and leptin seems to increase as body fat increases. The body knows how to regulate appetite and aims to be in a happy place, with weight as with all things. Obesity seems to mess up these signals and obese individuals seem to be 'leptin-resistant' - while they produce more leptin due to the fact they are carrying ample food stores in the form of body fat, their bodies don't seem to respond to the leptin cues as they should.
So why does sleep make you eat more? One of the study authors, Dr. Calvin, breaks it down:
The truth is, they're still trying to figure this whole obesity thing out. My inner 4-year old has got to know "Why?" whenever I learn a new fact or read about a new piece of research.
Carbohydrate metabolism may be a part of the puzzle. The Canadian Obesity Network has added adequate sleep to its obesity treatment guidelines, and reports:
Sleep deprivation directly and measurably affects the health of adults and children. Both insulin and glucose metabolism are negatively affected, resulting in slower glucose clearance, lower insulin response to glucose, a lower disposition index, and lower insulin sensitivity. All are early markers of health issues, such as diabetes and hyperglycemia, associated with obesity.
The stress hormone, cortisol, has also been shown to be higher in sleep-deprived individuals. In addition, cortisol has a direct link to central adiposity (abdominal fat) and insulin resistance.
All very interesting if you're in my line of work.
I am going to keep my eye on the research, but I'm also going to channel my inner Buddha here and stop asking questions, and I suggest you do the same. While they haven't determined the exact mechanisms, it is clear that exercise, a moderate diet AND adequate sleep are all major factors in the maintenance of healthy body fat levels.
The average American gets only 6 of the recommended 7-9 hours of sleep per night. This might not be you. But, odds are, it's you or it's the dude sleeping next to you (or not sleeping)!
Here's what you can do:
- Use your PVR to catch your favourite late-night dramas the next day while you walk on the treadmill or do some ironing. That is, assuming you wear actual clothes to work and not head-to-toe lycra, as I do.
- Head to bed an hour early with a cup of herbal tea or some carbonated water and read a book to ease yourself off to dreamland a little earlier.
- Stop using electronic devices before bed (if you're quite sensitive or sleeping very poorly, I would include TV in this category); their blue light messes with your body's sleepiness signals.
- Nap if you can. While it's not the same as nighttime sleep, there is some truth to the idea of a "sleep bank" and 20-30 minutes in the late morning or afternoon might help you stave off cravings and feel more calm and alert.
- Darken lights, dim noise, turn down the thermostat and even try a hot bath or shower before bed to help you ease into nighttime mode. Just like you used a bedtime routine for your infant, your brain and body will respond to bedtime cues.
- Darken your bedroom as much as possible, with curtains or black-out curtains if you can, to enhance the sleep-inducing hormone melatonin. Switch LED alarm clocks to old fashioned clocks and disconnect blinking electronics before bed. Keep the room cool to help you nod off and stay asleep.
And... my top tip:
Put your kids to bed earlier. If bedtime for the kids is at 9:30 p.m., you could be up until 11:30 p.m. or 12:00 a.m. just to get a couple of grown-up hours to do housework, have a glass of wine, catch up with a girlfriend or lounge around slack-jawed and shell-shocked from the bath-dinner-bed routine. Get the little ones up 30-60 minutes earlier in the morning, put them down earlier at night and get to your time sooner so you can go down sooner too.
How many hours per night do you get? What helps you feel sleepy and ready to relax? Share your tips here!