As I scour the weight loss research, it seems like almost every month there is a new study demonstrating the power of a good night’s rest, especially on our waistlines.

Here are a couple of good studies I’ve recently run into, both of which made me stop, reflect, and lay down – just a few minutes earlier than usual.  It’s a good start, right?

Study 1 – Sleep Loss Linked To Muscle Loss

Ideally, when you lose weight, the goal is to lose pure fat while maintaining (or for some, gaining) lean muscle, right?

While it is nothing new that sleep habits are linked to body weight, a recent study by the University of Chicago reveals a fresh connection between the two.

They have shown that, while dieting, sleep deprivation can actually lead to a loss of muscle mass.

The Study

Their study, published in the Annals of Internal Medicine, followed the sleep patterns of 10 overweight men and 10 overweight women, and took place in the controlled and observable setting of a sleep lab.

The study took place over two separate two-week periods.

All of the participants were kept on the same reduced calorie diet for each of the two week periods.

During the first two week period, the participants were required to sleep for 8.5 hours per night, which sounds pretty nice to me!

For the second two week period, the participants slept only 5.5 hours per night – and remember the participants’ diets stayed the same during both weeks.

The Results – Sleep Protects Muscle

Senior researcher, Dr. Plamen Penev, reported that during each two week period, about 7 pounds were lost, on average, by all of the participants.

However, Dr. Penev notes that “the composition was different,” of the pounds lost during each period.

To clarify, when study participants got 8.5 hours of sleep, more than fifty percent of the weight lost was from pure fat.  This is what we want when looking for successful weight loss!

When participants slept only 5.5 hours, it was discovered that only one quarter of the weight came from fat – and what is most telling, 55% of the loss was from lean tissue.

Lean tissue is muscle and other non-fatty tissue! This is not what we want to lose!

Real World Application

Dr. Penev and his team also reported that during the 5.5 hours per night sleep period, the participants reported being hungry more often – even though the participants stayed on the same diet during both trials.

So, what does this mean in the real world?

Odds are fairly good that if the participants had not been in a controlled environment, they may have decided to eat something not on their diet plan and would have less of a chance to lose weight.

One thing this study does not address is the duration of the “perfect night’s sleep” that each person needs for their nightly rest to also aid in weight loss.

The researchers could not make a universal claim because everyone’s requirements are different, says the study’s co-author, Dr. Shahrad Taheri.

In conclusion, this study adds to the research on sleep habits and weight loss, and suggests that if you’re trying to lose weight by reducing calories alone, you should pair your diet with a full night’s sleep to ensure you’re losing pure fat and not muscle.

(Also – one thing I thought of that is not mentioned…exercise wasn’t a factor here – I bet that by adding that to the mix, the results could be totally different, but that is for another article.)

The Take Home

The researchers leave us with some lasting advice, regardless if we are trying to lose weight or not.

They suggest we all take the time to learn the unique rhythms of our own bodies.  Notice how “refreshed” you feel when you wake up from a solid night of sleep –for some it may be 8 hours and for others only 6 to 7 hours.

Allow yourself to sleep in and find out!  Is there anyone who wouldn’t want to participate in that experiment?

Study 2 – Turn Off the Night Light

I emailed a few of you about this already, but I wanted to share again…an article just published in the Proceedings of the National Academy of Sciences shows that you may gain weight just by sleeping with a dim light on, like the glow from a night light.

Researchers discovered that mice exposed to dim light during their sleeping hours gained 50% more weight than mice sleeping in total darkness.

To test the significance of the light in relation to other factors, the researchers went ahead and reduced the calorie intake of the mice sleeping with the dim light on, and they added also more exercise to their routine.

Even with this intervention, they still gained more weight than the mice sleeping in total darkness – pretty crazy stuff.
The authors of this study, from the Departments of Neuroscience and Psychology at Ohio State University and the Israeli Center for Interdisciplinary Research in Chronobiology at the University of Haifa, also found that the mice not sleeping in total darkness experienced glucose intolerance (a pre-diabetic condition).

It is too early to tell if this study will translate in the exact same way to humans.

However, common sleep help advice suggests you stop using anything with an artificial glow – like watching television or playing on your laptop or cellphone – a couple hours before you go to bed.

So, if that is true, and this study is true for animals, I would assume that there has got to be a relationship between sleeping in dim lights for humans, too.

Starting tonight, I’m going to un-plug my Mickey Mouse night light and I am going to try to turn in – in complete darkness – at a consistent time every night…wish me luck.

PS – If you’re interested in reading more on this important health issue, check out our past article: http://exploringthemind.com/the-mind/secrets-of-sleep-revealed on shift-work disorder and the health issues for those who lose sleep when switching late night work shifts.
Sources: Nedeltcheva, Artlet V., et all. “Insufficient Sleep Undermines Dietary Efforts to Reduce Adiposity.” Annals of Internal Medicine. October  2010. Vol. 153, no. 7: 435-441.
Bedrosian, T.A., Fonken, L.K., Walton, J.C., Haim, A., & Nelson, R.J. “Dim Light at Night Provokes Depression-like Behaviors and Reduces CA1 Dendritic Spine Density in Female Hamsters.”  Proceedings of the National Academy of Sciences. October 2010. Published Online.