Be Sure to Get Your Weight Loss Sleep!
Sometimes when I harp on the importance of sleep to my patients, I see their eyes glaze over a bit. This is one of those times where ‘familiarity breeds contempt’! We’ve all heard, ad nauseum, about the importance of sleep and people like me are constantly beating the drum about not being able to heal from chronic disease without adequate sleep. However, now there is evidence that the effects of recurrent sleep deprivation reach even further…to the realm of metabolism and weight gain!
Benedict C, Vogel H, Cedernaes J, et al. Gut microbiota and glucometabolic alterations in response to recurrent partial sleep deprivation in normal-weight young individuals. Molecular Metabolism [serial online]. October 24, 2016;5(12):1175-1186. Available from: MEDLINE Complete, Ipswich, MA. Accessed December 27, 2016.
The participants in this study were nine, normal weight men. Researchers collected stool samples before and after two normal sleep nights and also two sleep-deprived nights. The stool samples were then analyzed to determine the identity and relative quantity of the bacteria in the colon. A normal night was defined as 8.5 hours of sleep and a deprived night was 4.25 hours. Additionally, researchers gave each participant an oral, glucose tolerance test to look at insulin sensitivity (keep in mind, decreased insulin sensitivity means increased insulin resistance).
There were two, major takeaways in this study.
Microbial Diversity – when determining the identities and amounts of bacteria in the stool before and after just two days of sleep deprivation, they found that the relative ratio of ‘Firmicutes’ to ‘’Bacteroidetes’ was increased. Therefore, in just two days, Firmicutes went up and Bacteroidetes went down (this is a bit over-simplified…but the net result is the same). Here is the important piece and where this research dove-tails onto previous work: Guess where increased ratios of Firmicutes:Bacteroidetes is seen? Yep, not only in obese mice, but also obese humans! It is speculated that Firmicutes make us ‘hyper-efficient’ at extracting every last calorie from our food! So imagine that you have two people eating the exact same food with exact same caloric levels. If one of those people has loads of Firmicutes relative to their Bacteroidetes population – they will extract more calories from the exact same food!
Glucose Metabolism – this is huge!! After just two days of restricted sleep, the study participants exhibited 40% greater increased insulin resistance! Additionally, fasting insulin levels were 34% higher after those two days of restricted sleep. When you read increased insulin along with insulin resistance, you should be making a connection to obesity, metabolic syndrome and diabetes!
The authors mention a body of research that has shown repeatedly that mice with no microbes in their guts (‘germ-free’ mice) do not become obese when fed a ‘Western diet’. However, when these same mice are inoculated with the bacteria from the guts of obese mice (or even obese humans) and then fed the same diet – they become obese!
WIIFM? (What’s In It For Me?)
This is an easy one: Sleep! Even if you are relatively healthy, you can see that even short term sleep deprivation leads to profound changes in the microbiome and your ability to metabolize sugar efficiently. For those who are struggling with chronic disease, the consequences become quite profound as the effects of sleep loss become even more wide-reaching. Remember the laws of diminishing returns. Nowhere is this principle more biologically sage than when talking about the effects of sleep deprivation. Most people stay up too late because there is simply too much do and night-time hours are often quiet ones in which we can work without interruption. But consider the time it takes to complete a task in a sleep deprived state vs. when you are well-rested. In my own life, I’ve found that the hours I save efficiently working in a rested state are more than worth going to bed at a decent hour and getting the sleep I need.