William Dement, a sleep researcher at Stanford, convinced me with this book of the importance of light hygiene. I do not sleep well if there's any light in the room. The modern world is full of light sources: clocks, power strips, computers -- even when they're supposedly off, our myriad electronics have little LEDs glowing, red or green or yellow, little eyes in the dark. Real darkness is not a matter of turning off the lights. It's a matter of blacking out your windows and covering up all those little eyes. Dement demonstrated in the lab that even these little increments of light disturb people's sleep: although they're unaware of why, they sleep less soundly and wake more easily in the presence of even very little light.
Sleep gets its own entry in my "whupping the food thing" series for two reasons. First: sleep is the great restorer of oomph, and everything about whupping the food thing rests on oomph. To eat right I need to plan ahead, to not always take the easy way, to throw myself into the fight with some vigor and enthusiasm: above all, to keep out of temptation's way, and to occasionally resist temptation if my planning fails. All those things require oomph, and if I start the day with a meager supply, chances are there won't be enough when my trough times come. If I'm exhausted, grieved, discouraged, and out of oomph by mid-afternoon, the odds that I'll be gorging on ice cream and potato chips before the end of the day skyrocket. I can't afford not to get a good night's sleep.
The other thing sleep does is relieve persistent pain. I'm not sure if it does this by actually encouraging the repair of tissue, or more subtly by somehow resetting the brain's pain responses, but the effect is striking. Most people my age or older are navigating their exercise around some pain or other, their "bad knee" or their "tweaked back" or something: we're working the trade-offs between the benefits of exercise and aggravating some pain or other. The catch-22 here, of course, is that to really get a good night's sleep, you have to exercise. I have clients in whom this has spiraled down to an almost sleepless and completely pain-filled life, getting around by motor-chair because they can't walk on their excruciating knees, unable to drive because they fall asleep at the wheel, unable to sleep because their body is desperate for exercise, and unable to exercise because everything, everything hurts. Trust me: you really, really don't want to go there. And the simplest intervention in this vicious cycle is a remarkably easy one. Block every single damn light source, block it completely. If you want to get fancy, it also helps to quit using televisions and computers for an hour or two before bed. Those are both powerful light sources, and you stare straight into them. I've never managed to do that: I'm too fond of dinking around on my computer in the evening. For me, it's enough to make it dark dark dark. Blackout curtains, clock hidden under the bed, duct tape on the power strip light. Really dark.
What does avoiding pain have to do with whupping the food thing? Well, exercise turns out to be critical for a normal metabolism. Whatever goes wrong with modern metabolism, and disposes us so disastrously to type II diabetes, cardiovascular deterioration, and cancer, study after study shows that exercise militates powerfully against it. I believe there's much more to it than the simple fact that exercise burns calories: the human body is designed for activity, and a whole slew of things begin to go wrong when it's sedentary, a cascade of ill-effects and metabolic abnormalities. My guess is that almost nobody with disordered eating regulation is going to really fix it without becoming active: and that almost nobody sedentary is going to become active if it's painful. So we come back to sleep. Protect it, cultivate it, defend it fiercely. Sleep is your friend.