Tuesday, December 20, 2011

Sleep, Circadian Rhythms, and Weight Loss


Is there a standard amount of sleep folks need?  I typically sleep 5.5-6 hours per night and have for years.  I do feel better with more but do not noticeably function better (may just be years of kidding myself).  

It does seem easier to lose weight when sleeping more (diet and exercise staying constant).  Does this make any sense or is it my imagination?

Gender: Male

How old are you?: 46

Check all symptoms you are currently experiencing:
None of these
No medications

Are you currently using or do you have a history of tobacco use?: Yes
Are you currently using or do you have a history of illegal drug use?: No
Please describe your alcohol consumption :: Weekly


typical need for sleep
short term impact of lack of sleep
recovery from lack of sleep (1 nights good rest, more?)

So Joe,

Your question is very complex. The issue about 'how much sleep is enough' does tend to vary from individual to individual and we are not sure why. First, let me point you to THIS SITE, which is, at least, an interesting read.

Two highlights from this site....

Though scientists are still learning about the concept of basal sleep need, one thing sleep research certainly has shown is that sleeping too little can not only inhibit your productivity and ability to remember and consolidate information, but lack of sleep can also lead to serious health consequences and jeopardize your safety and the safety of individuals around you.

For example, short sleep duration is linked with:

Increased risk of motor vehicle accidents
Increase in body mass index – a greater likelihood of obesity due to an increased appetite caused by sleep deprivation
Increased risk of diabetes and heart problems
Increased risk for psychiatric conditions including depression and substance abuse
Decreased ability to pay attention, react to signals or remember new information

According to researchers Michael H. Bonnet and Donna L. Arand, "There is strong evidence that sufficient shortening or disturbance of the sleep process compromises mood, performance and alertness and can result in injury or death. In this light, the most common-sense 'do no injury' medical advice would be to avoid sleep deprivation.

And on the other hand....

 ...some research has found that long sleep durations (nine hours or more) are also associated with increased morbidity (illness, accidents) and mortality (death). Researchers describe this relationship as a "U-shaped" curve (see illustration) where both sleeping too little and sleeping too much may put you at risk. This research found that variables such as low socioeconomic status and depression were significantly associated with long sleep. Some researchers argue that these other variables might be the cause of the longer sleep: the fact that individuals with low socioeconomic status are more likely to have undiagnosed illnesses because of poor medical care explains the relationship between low socioeconomic status, long sleep and morbidity/mortality. Researchers caution that there is not a definitive conclusion that getting more than nine hours of sleep per night is consistently linked with health problems and/or mortality in adults, while short sleep has been linked to both these consequences in numerous studies.

And as to the weight and sleep part of your question, well, that's a rat's nest indeed, but, as you may guess, there does appear to be a link between not-enough sleep, and obesity. THIS LINK here is pretty in depth and gets all doctor-y, but you will get the idea.

And to open another can of worms, there is a raft of medical evidence out there on CIRCDADIAN DISRUPTION... jet lag if you will.... rotating shift work.... Bottom line. It sucks. In fact, it's probably the main reason that I will pay to get out of night shifts in the ER.

More to follow.... this is hard to do on an Iphone.


DOC2 said...

Doc2 here. Thank you for your question. The maintenance of proper circadian rhythms are important. All of the processes however are not well understand and most of them are conjecture. We have tried to elucidate body processes during sleep with PET scans, EEGs, etc. However, we cannot grasp (without waking the subject up), what happens entirely. The best that we understand is that your body has a checklist of things to do every sleep cycle. As you might imagine, the brain is in a constant state of doing stuff (sometimes working hard and sometimes not working so hard). It works hard for our conscious mind and body during the day, and then it does work for the the body during the evening. (It's tough being the CEO sometimes.) To fulfill all of its obligations to the body, it has to have time allotted to do the job right. It also has to have time to recharge itself so that it can get ready for the stuff that you want it to do the next day.

There isn't a an easy answer to your question however, because it is subjective to the individual. Generally 8 hours of sleep is pretty acceptable. However, you may require more or less depending on your individual wiring. There have been studies which showed that as little as one hour of sleep deprivation taken over one week could cause a decrease in the ability to think clearly to perform a task (aka cognitive function). There are also links between poor blood sugar control in diabetics as a result of sleep deprivation. This usually goes hand-in-hand with obesity/overweight.

If you remember a having a night where you didn't get any sleep, you probably remember feeling tired, sore, etc. If you extrapolate that out to the rest of the body and applied this "tiredness" to every body system, then you have the result of sleep deprivation. Immune function is lazy, muscles are lazy, the brain cognitive function is lazy...etc. The sleep-wake cycle (at the conclusion of sleep) causes you to wake up properly and allows the body systems to "wrap it up" so to speak. If the bell rings too early and without warning, the body is a bit "stuck with its pants down" not having properly completed the needed tasks for the sleep cycle.

Not getting good rest requires the body to go into a state of conservation and stress. That stress hormone that you hear about in the commercials "cortisol" plays a major role. Too much of this causes poor blood sugar control and weight gain (or at least a decreased ability to lose weight). I see this constantly in my weight-loss practice. It doesn't matter what you do with your diet and with exercise or taking medicine for weight loss, you will not lose or would not lose an expected amount of weight if you have too many stressors in your life. Without sleep, stress is amplified.

Hope this helps.

space doc said...
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