Pure Pedantry

Sleep is an underappreciated thing. Not only does it improve your memory, but now we find it would appear lowers your risk for obesity:

Research by Warwick Medical School at the University of Warwick has found that sleep deprivation is associated with an almost a two-fold increased risk of being obese for both children and adults.

Early results of a study by Professor Francesco Cappuccio of the University of Warwick’s Warwick Medical School were presented to the International AC21 Research Festival hosted this month by the University of Warwick.

The research reviewed current evidence in over 28,000 children and 15,000 adults. For both groups Professor Cappuccio found that shorter sleep duration is associated with almost a two-fold increased risk of being obese.

The research also suggests that those who sleep less have a greater increase in body mass index and waist circumference over time and a greater chance of becoming obese over time.

Professor Cappuccio says:

“The ‘epidemic’ of obesity is paralleled by a ‘silent epidemic’ of reduced sleep duration with short sleep duration linked to increased risk of obesity both in adults and in children.These trends are detectable in adults as well as in children as young as 5 years.”

Professor Cappuccio points out that short sleep duration may lead to obesity through an increase of appetite via hormonal changes caused by the sleep deprivation. Lack of sleep produces Ghrelin which, among other effects, stimulates appetite and creates less leptin which, among other effects, suppresses appetite. However he says more research is needed to understand the mechanisms by which short sleep is linked to chronic conditions of affluent societies, such as obesity, diabetes and hypertension.

Now, I would note in the spirit of honesty that this appears to be a case-control study. (I don’t know for certain because this was published at a conference, so I can’t read the paper.) Anyway, since was a case-control study, it does not necessarily show that lack of sleep leads to obesity, just that they are associated. Nor does it show that increasing your sleep will lower your weight.

They do make an argument as to etiology — which is important, and I do think that argument is pretty reasonable.

The take-home I guess would be that although it is not certain, you should probably get some sleep.

By the way, just anecdotal evidence that lack of sleep is associated with weight gain is that whenever I am up late at the lab, I always feel compelled to get pizza. I guess I think I am rewarding myself for working hard. Sufficeth to say, lately I have been eating a lot of pizza.

Also incidentally, it would appear that Warwick University has started attaching podcast interviews with the authors of the studies in their press releases — which is pretty swanky. Here is the podcast interviewing the author of this study.

Hat-tip: Future Pundit.


  1. #1 coturnix
    July 18, 2006

    That idea’s been floating around for the past couple of years. On the other hand, if you sleep too much, you are more likely to have Parkinson’s when old (again a correlation with no causation). So, you have to find your own perfect Goldilocks solution…

  2. #2 st
    July 18, 2006

    um, not a very revealing study, at least as presented in the press release – obesity is causal to sleep disturbances like sleep apnea, not consequent to it…maybe the u of warwick media folks got ahead of themselves, peer review is a lovely thing.

New comments have been temporarily disabled. Please check back soon.