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/ http://www.glamour.com/magazine/2009/02/lose-weight-while-you-sleep
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.