Are You Tired? (It could be tied to weight control.)

++  An area of research that I find exciting has been developing in the past few years:  Is partial sleep deprivation contributing to obesity?

  Partial sleep deprivation, for research purposes, is defined as frequently getting less than 6 hours sleep per night (or day).   Most of the studies done so far look at connections but can't prove cause-and-effect.  They show that the less sleep you get, the higher your energy balance; that is, the more likely you are to take in more calories than you use.  That leads to the assumption that the less sleep you get, the harder it is to control the amount of body fat you accumulate. 

  The suggested reasons for this are many, and need more research.  These are the biggest factors they have been looking at so far:

• While you sleep, some of your hormones hit the reset button (figuratively speaking).  If you don't get enough sleep, hormones that regulate appetite get out of balance (the main ones are ghrelin and leptin).  Insulin might also be affected. 
• If you are awake more, you munch on snacks more.
• If you're sleepy, you tend to be sluggish and get less physical activity. 

  I'd like to see more studies that cover real-life situations, like averaging 5-6 hours/night for several months; or having sleep interrupted a lot (e g. you're saying you're in bed 8 hours, but the baby wakes you every 2 hours).