Can lack of sleep contribute to obesity?

I don’t believe that the best way for people to lose weight is to consciously restrict how much they eat. I have no issue with people eating less, I just believe that, for the best results, it needs to be done in a way that is both easy and sustainable. For the most part an essential component here is a regime that does not induce undue hunger. My preference is generally for a carbohydrate controlled diet ‘primal’ diet. Such a diet will usually provide enough protein to keep the appetite sated, while allowing fat loss from fat tissues which can then ‘feed’ the body, thereby potentially quelling appetite through this mechanism too.

However, what we eat (and how much) is not the only lifestyle factor that can affect appetite. It’s been know for a long time that sleep has a role to play here. Studies have found that sleep deprivation can induce changes in hormones that regulate appetite. For example, sleep deprivation has been found to boost levels of the hormone ghrelin – a hormone that stimulates appetite. Sleep deprivation can also lower levels of the hormone leptin. This is not good, seeing as leptin not only suppresses appetite, but also speeds the metabolism.

I was interested to read of a study recently which tested the effect of sleep deprivation on appetite ratings in response to images of food [1]. In this study, individuals were tested on separate occasions after either a night or normal sleep, or total sleep deprivation the previous evening. Overall, subjective feelings of hunger were significantly greater after the night of sleep deprivation. The study subjects underwent brain scanning too (functional magnetic resonance imaging). After a night of sleep deprivation, there was enhanced activity in a part of the brain known as the anterior cingulate cortex. This structure, among other things, influences our sense of appetite and hunger. The increased appetite ratings and activity in the anterior cingulate cortex were seen after a night of sleep deprivation, despite the fact that blood sugar levels were the same as after a good night’s sleep.

What this study provides is further objective evidence that a lack of sleep might drive a tendency to overeat. For some people, therefore, it may make sense to ensure adequate sleep if the goal is to attain and maintain a healthy weight.


1. Benedict C, et al. Acute Sleep Deprivation Enhances the Brain’s Response to Hedonic Food Stimuli: An fMRI Study. J Clin Endocrinol Metab 2012 Jan 18. [Epub ahead of print]

10 Responses to Can lack of sleep contribute to obesity?

  1. Fiona 10 February 2012 at 3:39 pm #

    I’ve started tracking what I eat, as recommended in your book, and noticed that after a couple of sleepless nights due to a sick child, I ate approximately 300 more calories than on days when I had a full night’s sleep! It also made me wonder if this is why new mothers have difficulty losing ‘baby weight’ when they have such broken sleep? Perhaps they are unknowingly eating more than they think? I certainly didn’t notice that I was eating more during that recent spell of bad sleep, but found myself waking up very hungry in the morning, which is not usual for me, and continuing hungry through the day, and to me it felt like blood-sugar disruption rather than real hunger.

  2. frances 10 February 2012 at 7:08 pm #

    I definitely eat more when i’m tired and not in a position to take a nap – i think it’s in a misguided attempt to up my energy levels.

    Not trying to be negative, but… these photos aren’t doing you any favours! They are deeply silly.

  3. Jennifer Eloff 10 February 2012 at 8:19 pm #

    This is very true for me as well. When I am tired, I will eat more – for sure! I shared your article; it was very informative. Thanks! Have a nice day. 🙂

  4. Kyle Knapp 10 February 2012 at 8:42 pm #

    I have noticed this personally as well. When I wake early- I am hungry ALL day. When I get adequate sleep, I have “normal” hunger. Before I understood the impact of sleep on the body, this “phenomenon” used to blow my mind… 🙂

  5. Margareta Lundström, Sweden 10 February 2012 at 10:51 pm #

    Absolutely tru dr Briffa. After a bad nights sleep I urge for food in the morning. Normally I do not eat breakfast until have done some 2-3 hours of housework.
    When I worked nightshift as a nurse (ages ago) I just ate and ate after the shift and I seemed never to be satisfied.

  6. Helen 10 February 2012 at 11:18 pm #

    I agree totally with Dr. Briffa’s belief that counting calories to loose weight is not the answer; and, without any testing, I can also confirm that lack of sleep makes you eat, which makes you fat. I have insomnia and never get down into levels 3 and 4 of sleep. Even with heavy medication to get to sleep and stay asleep, I have often gotten up to eat with no memory of doing so (sleep walking/eating). The sleep lab cannot explain why I have insomnia and medication is not working anymore after many years, to get some sleep. I believe the answer lies in my diet, specifically the right kind, and amount of protein to turn off the grehlin and turn up the leptin but I also need complex carbohydrates, like potatoes and high fibre bread, something we had at every meal as children, which is ancesteral in our family. Also, we can’t get on a bus or watch TV without being bombarded by food ads. I must be related to Pavlo’s dogs because often, but not always, these ads will make me salivate against my will. So there is some conditioning involved, but my main point is that I eat at night because I am unable to get quality sleep, night after night, after night. I’d like to think that if I could sleep I’d stop eating, it seems sometimes, all night long. Fixing the sleep problem has a direct connection to the over eating that causes the weight gain and/or the inability to loose weight. And no amount of deiting (which I don’t do anymore) or counting calories is going to fix the weight problem. I believe the sleep issue needs to mitigated before the weight issue can me dealt with.

  7. Ronnie Plant 11 February 2012 at 1:08 am #

    My recent book ‘SELLING SICKNESS?’, sub titled How to take control of our own health, dwells on my slogan We are as we Eat, Sleep, Drink and Exercise. I am convinced that you are right in your assumptions. As an 84 years young man, with normal weight, I realise that eating less is not the answer to losing weight. Eating pure and natural additive free and non processed food as well as drinking pure water, taking exercise, with regular sleep and sleep pattern, can work wonders.

  8. Greg Venning 11 February 2012 at 1:22 am #

    This is such a vital cog in the wheel of correcting damage to our metabolic machinery. A great book to read is Lights Out: Sleep, Sugar and Survival by TS Wiley and Brent Formby PhD.

  9. Chris 11 February 2012 at 9:43 pm #

    Sleep deprivation and fatigue induced by queer working hours and long hours are definitely triggers that can induce hunger, food cravings, or carb cravings in me. They also induce increased desire for measures of beer or wine that can accompany hastily prepared fodder.

    Even though I recognise the trigger and ought to be able to counter it there are factors beyond my control that can trigger the fatigue and the compulsive eating. I expect others may have similar issues. Shift work, or a working day length that can vary considerably and is not within direct personal control are circumstances that can disrupt the kind of routine that discourages fatigue or encourages regular meals or mealtimes. When the alarm is set for 3am I find an arduous day, or a day length of 13-15 hours, is disruptive enough to cause a vicious circle that can continue several days.


  1. More evidence comes in that lack of sleep might drive over-eating | Dr Briffa's Blog - A Good Look at Good Health - 23 February 2012

    […] this month I wrote about a study in which the effect of sleep deprivation on appetite ratings in response to images of food was […]

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