A couple of nights ago, though, I was home, and here’s what happened. Our four-year-old son, Joshua, slipped into our bed. Samuel was sleeping soundly, which was nice, but Alexis was teething, and Nicki was up from two until six a.m. helping her get through the painful adjustment.

Poor Nicki’s doing the best she can, but she told me that when her rest is wiped out, all she wants to do is snack, snack, snack the rest of the day. That’s when she told me that all she wants to do is eat after she’s up half the night.

What Nicki said makes sense. The truth of the matter is that University of Chicago researchers have found a link between the lack of sleep and the risk of weight gain. They were able to identify how a lack of sleep boosts the appetite, especially for high-calorie, high-carbohydrate foods. What happens is that sleep lowers leptin, a hormone that tells the brain that it doesn’t need more food, and elevates ghrelin, a different hormone that triggers hunger. When test subjects slept only four hours nightly, leptin levels decreased by 18 percent and ghrelin levels increased 28 percent.

Ever since Joshua’s birth, Nicki and I have become more and more cognizant of the importance of sleep in our lives. For one thing, Nicki realized how much she missed a good night’s rest during Joshua’s first few years. I felt unrefreshed as well when I woke up, especially when I volunteered to give Joshua his bottle in the middle of the night. We used to go to bed around 11 p.m. and wind down with a half hour of local news or catch part of Leno or Letterman, but those days are long gone. We’re turning the lights out a lot closer to 10 p.m. than 11.

My favorite sleep story happened during a trip to Switzerland three years ago to celebrate our sixth wedding anniversary. Nearly all air travel from the U.S. to Europe are overnight flights, so when we landed in Zurich at 8 a.m. local time, we were still on Eastern Standard Time—2 o’clock in the morning. I got some rest on the plane, but Nicki hadn’t slept a wink.

My writer, Mike Yorkey, and his Swiss-born wife, Nicole, were waiting for us at Zurich’s Kloten airport. They proposed taking the scenic route from Zurich to the family chalet in Villars. Instead of driving the more direct path on the fast autobahn, Nicole said we could detour on secondary roads that would lead us through the heart of the Swiss Alps—the Interlaken region, home to Heidi and the majestic Eiger mountain.
We wish we could tell you that we were stunned by the beauty of the Brünig Pass, which gave us our first glimpse of the Eiger’s North Face, still snowcapped on this September morning. We wish we could tell you about the magnificent chalets constructed from Norwegian pinewood and accented with window boxes that overflowed with white, orange, and blood-red geraniums. We wish we could describe the coral-blue Thunersee, a glacier-fed lake teeming with windsurfers and pleasure boaters on that Sunday morning.
The reason we can’t do any of those things is because we were fast asleep in our Renault rental car.

No matter how hard we tried, we couldn’t keep our eyes open during the five-hour journey. After arriving in Villars, our hosts recommended that we take a short walk to “keep you two going.” Getting some fresh air gave us a burst of energy and kept Nicki and I engaged during a delicious dinner of Swiss fondue—wedges of organic pain rustique dipped into a bubbling mixture of Gruyère and Vacherin cheeses. But we tired quickly and turned in early. At 8:30 p.m., after tucking myself underneath a dreamy duvet, we both fell into a deep sleep the moment our jet-lagged heads hit the fluffy pillows. We were dead to the world.

I woke up thirteen glorious hours later and enjoyed a late-morning breakfast with the Yorkeys. At 11 a.m., I wondered if I should interrupt Nicki’s slumber. Nicole, a mother who knows that you never wake up a sleeping child—or a mom—demurred. “Let her sleep,” she said.

Noontime passed on a dazzling, sunlit afternoon, as did one o’clock. Nicki was fast asleep in a bedroom that was pitch black, thanks to shutters that closed over the windows.

At two o’clock, Mike suggested we start a March Madness-like pool on when Nicki would wake up. Thirty minutes later, it was apparent that she wasn’t going to wake up any time in the near future. If she didn’t get up now, they reasoned, then she might sleep past dinnertime, and then she would be really messed up.

I walked into our bedroom, making noises and opening the shutters. Bright sunlight filled the room, and Nicki came to life.

“What time is it?” Nicki wondered groggily.

“Two-thirty.”

Two-thirty? Something didn’t compute. “Morning or evening?” she said through a drowsy haze.

“You’ve been sleeping for eighteen hours,” I announced.

Eighteen hours. That was a new world record—at least for Nicki. I sure felt for her, though. There were weeks after she brought Joshua home from the hospital that she didn’t sleep more than eighteen hours. Grabbing that much sleep in a Swiss chalet probably felt like a guilty pleasure, but she deserved it after what she had been through for the last year-and-a-half. During Joshua’s first six months of life, Nicki never snoozed longer than spurts of three or four hours since he crankily demanded to be fed the best food available to an infant—a mother’s breast milk.
 
A sense of exhaustion is what every mother feels, which stems from not getting enough sleep and the tyranny of the urgent: taking care of the kids and tackling too many things around the house. If you’re a young mother like Nicki, then finding a full night of rest is an elusive pipe dream, even though we both know that sleep is a basic human need, something just as important to good health as what we eat and how much we exercise.

Since sleep lays the groundwork for a productive day ahead, it’s important to wake up to the importance of sleep. Adequate rest revitalizes tired bodies, gives you more energy, helps you think more clearly throughout the day, and puts all of us into better moods.