In a previous post I talked about how too little sleep may be the missing piece in the puzzle for weight loss. Especially if you’ve tried everything else. So the opposite may sound like the answer. Get all the sleep you can, and poof, the weight will come off. Makes some sense. At least while you’re sleeping, you’re not eating. But it’s been shown that sleeping in excess of 9 hours per night can be just as damaging to your sleep cycles and your waistline as not getting enough sleep.
People who oversleep experience a disruption in the body’s natural 24-hour biological cycle (the circadian rhythm) and because of this, over sleepers can experience a number of side effects as their bodies struggle to “sync up” with the correct time, leading to a whole slew of health issues associated with oversleeping.
Oversleeping has a powerful impact on how your body stores fat, and it’s ability to lose it. New research from the University of Glasgow has discovered that sleeping too long can make you gain as much weight – and potentially even more – than sleeping too little.
What’s too long, you ask? According to the researchers, anything beyond the realm of around nine hours – or under seven hours – puts you in the danger zone of having to unbuckle your pants.
Let’s take a look at a few of the findings:
Sleep duration impacts blood sugar fluctuations:
Glucose tolerance refers to your body’s ability to process sugars, and something called “impaired glucose tolerance” is associated with insulin resistance. It is also a risk factor for type 2 diabetes, heart disease and obesity. A Canadian study looked at lifestyle habits of 276 people over six years, finding that people with long and short sleep durations were more likely to develop impaired glucose tolerance, diabetes and ultimately obesity during the time span (20%), compared to normal sleepers (7%). Another more recent review of diabetes and sleep studies also found a significant relationship between increased risk of type 2 diabetes, diabetes and oversleeping.
Too much sleep could lead to obesity:
Using the same data as the Canadian study mentioned above, researchers also found an association between weight gain and excess sleep. Folks who slept in excess of 9 hours per night actually gained more weight than “normal” sleepers over a six year period, and were far more likely to experience a significant weight gain. As a matter of fact, people who consistently slept over nine hours per night were shown to be 21% more likely than normal sleepers to become obese! This association between sleep and obesity remained the same even when food intake and exercise were taken into account.
Those genetically predisposed towards obesity are most impacted:
According to the study’s lead researcher Dr. Jason Gill, these findings reveal that sleeping in the Goldilocks zone is critical to maintaining weight, particularly those who are genetically pre-disposed towards obesity. “In people with high genetic risk for obesity, sleeping for too short or too long a time, napping during the day, and shift work appears to have a fairly substantial adverse influence on body weight,” explains Dr Gill. “However, the influence of adverse sleep characteristics on body weight is much smaller in those with low genetic obesity risk – these people appear to be able to ‘get away’ with poorer sleep habits to some extent.”
The results showed that people who were naturally thin could effectively under or over-sleep without negative consequences, while those who were already overweight had no such leeway. Somewhat shockingly, the researchers also found that high-risk people who identified as being “long sleepers” were about 4 kg heavier than the norm, and those who identified as “short sleepers” were on average 2 kg heavier than the norm.
To reach these conclusions, Dr. Gill and his colleagues had to do a little more than peep through people’s bedroom windows, they comprehensively analyzed the quality of sleep of almost 120,000 UK residents over the course of several months.
At this point, the researchers are unsure why this occurs – it could be the fact that being over-slept or over-tired could lead you towards more emotional eating patterns, or it could be the other way around, in that being obese makes you stay in bed for longer.
Whatever the case, Dr. Gill’s findings join a wealth of research that points towards a common conclusion: sleep requirement is a hugely individual thing, but almost everyone needs between seven and nine hours every night. Though diet and exercise are critical components of healthy lifestyles, it’s also important to remember that sleep is inherently linked with how we eat (and how much), how we exercise (and whether or not we lose weight), and how we function on a daily basis. Your weight may depend on it.