The Sleep Diet: How to Lose Weight by Doing Nothing

A new study published in the Annals of Internal Medicine suggests that dieting and exercise are basically a waste of time if you aren’t getting enough sleep. The study pinpointed how fat cells lose their sensitivity to insulin when we are sleep deprived.  This hormonal kick in the gut means we not only have more trouble dropping pounds, but also feel hungry more often too.

Leading me to debate.. should I join the gym across the street, or save the cash and just sleep in?

Actually, as a father of a 10 month old baby, the question is pretty academic for me. New parents are on the front lines of out-of-whack hormones due to sleepless nights. 

Like most new dads, I gained 10lbs–and quickly too– when the baby arrived.  Now that I’m working hard at taking naps when the baby does, my elf-like/coquettish figure has returned (ie I just have my usual beer belly).

But enough about me: Let’s get back to the study

The Chicago study, led by Matthew Brady, compared a small group of sleepers’ insulin resistance after a week of getting 8.5 hours sleep to after a week of only 4.5 hours sleep. The effect was striking: sensitivity to insulin dropped 16% on average.1

[pullquote]Fat cells need their beauty rest too.[/pullquote]

As quoted by ScienceDaily, Brady said, “Many people think of fat as a problem, but it serves a vital function. Body fat, also known as adipose tissue, stores and releases energy. In storage mode, fat cells remove fatty acids and lipids from the circulation where they can damage other tissues. When fat cells cannot respond effectively to insulin, these lipids leach out into the circulation, leading to serious complications.”

In simpler terms, fat cells need their beauty rest too.

More sleep-diet facts

This isn’t the first study to look at the sleep/fat connection. 

A much larger study (over 70,ooo participants to date) has been looking at the connection for over 20 years. One of their findings is that women who sleep less than 5 hours a night weigh –on average– 5.4lbs more than those who sleep 7 hours a night.2

Another study conducted by sleep doc Michael Breus found that 7 out of 8 women will lose up to 15lbs in less than eight weeks by just sleeping more… not changing their diet or exercise plans a lick.3

Faster fat loss is not sleep’s only positive benefit for your figure. If you are dieting and getting good sleep, you’ll lose fat.  But if you’re dieting and getting by on less than 6 hours sleep a night, your body burns lean muscle at night instead.4

Sleeplessness (or its antithesis: partying all night long) is part of the “Freshman 15” effect noted among college students as well. And, of course, there’s the long term results of not getting enough sleep, including increased chance of diabetes, obesity, heart disease, and a notably shorter life span.

If you’re interested in more gory details, I wrote about this and other issues with chronic short sleeping here.

So, if you want your exercise and diet plans to effectively work,  make sure you’re regularly getting between 7-9 hours of sleep a night — this is still the amount of sleep most of us need on a regular basis.

Recommended reading on this topic: The sleep doctor’s diet plan: lose weight through better sleep, by Michael Breus.



First Image: Sleeping by Relaxing Music, CC.

1 Rosiane L. Broussard, David A. Ehrmann, Eve Van Cauter, Esra Tasali, Matthew J. Brady. Impaired Insulin Signaling in Human Adipocytes After Experimental Sleep Restriction: A Randomized, Crossover Study. Annals of Internal Medicine, 2012; 157 (8): 549-557

2 Gangwisch, JE, Malaspina, D.,  Boden-Albala,B. et al. (2005). Inadequate sleep as a risk factor for obesity. Sleep 28(10): 1289-96.

3 Jenny Stamos Kovacs, February 2009. “Lose Weight While You Sleep!”, Glamour/

4 Nedeltcheva, A.V., Kilkus, J.M., Imperial, J., Schoeller, D.A., Penev, P. (2010) Insufficient sleep undermines dietary efforts to reduce adiposity. Annals of Internal Medicine 2010; 153 (7):435-41.



  1. Danielle says

    If you’re well-rested, you’re more inclined to make smarter food choices. If you’re sleep-deprived, you’re more inclined to give in to temptation.

    I cite no sources; I am the source. 😛

    • Ryan Hurd says

      me too! isn’t that the best? I’ve even had lucid dreams in which I knew he was sleeping next to me and I’m interacting with him in the dream, sharing thoughts and talking. pretty incredible.

    • Ivy says

      I feel you. My Doodle has been teething lalety, and will nurse all.night.long. She’s two. Last month she would nurse maybe three times at night. This month she’s on me the entire night. I’m so tempted to go sleep in the living room some nights, but I know then none of us would get sleep. *sigh* Your photo was a good reminder that it won’t always be this way. Thanks. (Kritto from MDC)

  2. says

    Hi Ryan – I started with a disruptive sleep pattern about 10 years ago and put on weight for the first time in my life (8st up to 9 1/2 st). I’ve recently changed my diet (now wheat-free) and have gone down to 8 1/2 st and falling. Someone, somewhere, has said that those who are wheat intolerant will gain weight if they eat wheat. Interesting though that since going wheat-free I’m sleeping better because my gut is a lot less active during the night and is not keeping me awake with its grunts and groans! On the other hand, both my sons (aged 30 and 24) slept for England as teenagers but now sleep very little and have always been as thin as rakes. Clearly it’s not as simple as some researchers are suggesting – human physiology is still not terribly well understood despite what we’re sometimes led to believe.

  3. Ryan Hurd says

    A prominent ex-federal food expert in the US recently called wheat “the world’s perfect poison”, citing how today’s wheat is very different than the grain from even 50 years ago. My wife and I have trimmed wheat from our diets and both lost weight — and lost the wheat cravings which I never even “saw” because it was the water I swam in! anyways, thanks for sharing the connection to wheat and sleep difficulty.

    as for your sons and physiology being complex — yeah, to be sure, this Sleep Diet thing is still party to our individual genetics. what it does is put you in the top part of your personal spectrum for metabolism — when we are rested, the body runs more efficiently.

  4. says

    Hi Ryan:
    I’m always wary about these studies that draw conclusions based on coincidence, not causation. Does sleeping less mean you eat more carbohydrates? I think the carb/insulin response is far more responsible for the weight issue than sleep. Just by simply cutting out the carbs, my weight has dropped without any change in my sleep patterns. As for chocolate, I love it too!

    • Ryan Hurd says

      Hey Doug, it’s always good to be skeptical about these findings, especially when drawing inferences for our personal lives. But there’s several excellent threads of empirical research, including that when we are sleep restricted, we tend to overeat more (due to imbalances of hormones leading to cravings) in addition to the metabolism info I focused on in this article.