Not the most obvious culprit, but, there is a link between sleep deprivation and weight gain.
The latest research shows just how important sleep is for mental performance, mood, health and, of course, weight control (1).
Many studies show that, in simple terms, people who don’t sleep enough, weigh more (3,4). Interestingly, the level of chronic sleep deprivation and obesity have increased, at a similar rate, over the past 50 years (5).
In fact, studies are beginning to show that sleep deprivation is an independent risk factor for weight gain and obesity (3,4,8).
One meta-analysis of 45 studies totaling 600,000 subjects, showed “a consistent increased risk of obesity amongst short sleepers in children and adults.” This increase in risk was shown to be 89% in children and 55% in adults (1).
This same study’s data suggested that a reduction of one hours sleep a day would be associated with around 1.4 kg in weight gain (7).
40% of American adults say that they get less than the minimum recommended 7 hours of sleep per night. 9 hours is the recommended maximum (2).
How Sleep Deprivation Leads to Weight Gain
There are two schools of thought and four main rationales when trying to explain the mechanisms that link insufficient sleep and weight gain.
Firstly, calorie intake is increased by allowing more time to eat and interfering with hunger hormones (10).
Secondly, the capacity to burn off calories is reduced by slowing the metabolism. Ensuing fatigue also reduces physical activity (9,7).
Let’s break down these 4 factors down further.
Sleep Deprivation Increases Time Available to Eat
Research shows that the longer the time you’re awake, the more opportunity you have to snack (6). These snacks, mostly consumed at night, are generally lacking in quality too. Studies show that these snacks are most convenient, high-fat and high-carb (2). The types of which are calorie dense and less likely to satisfy.
Late night eating has been shown, in at least one study, to increase the time it takes subjects to fall asleep (4). Thus taking away from quality sleep. A double whammy.
Sleep Deprivation Affects Your Hunger Hormones
Research has shown that people who lack sleep tend to eat more during the day (9). As mentioned above, the reasons are probably twofold i.e. increased time available for snacking and the disturbance of hormones that control appetite and hunger.
Studies show that lack of sleep increases ghrelin, the hunger hormone, thus increasing hunger. At the same leptin, the ‘fullness’ hormone’, is decreased. This leads to more eating, and eventual weight gain (10).
This is a natural response of our bodies making sure we’re fuelled for longer waking times. But this repeated behavior may eventually contribute to obesity.
Sleep Deprivation May Slow Your Metabolism
Recent research suggests that too little sleep can reduce energy expenditure and body temperature (9,7).
This means we probably burn fewer calories at rest during the days when we haven’t slept enough. And this leads to weight gain. The energy in is greater than energy out.
Sleep Deprivation Reduces Exercise Participation
This is probably the most obvious way in which lack of sleep can lead to weight gain (3,6). Naturally, the increased fatigue after being sleep deprived can reduce the motivation to partake in exercise. Energy out is much less than energy thus increasing the risk of weight gain.
Strategies For Getting Better Sleep
Lack of sleep is a modifiable risk factor. So whilst it’s been shown above to increase the risk of weight gain and obesity, it is entirely possible to implement strategies to get more.
1. Prioritize sleep
Our lack of sleep is often caused by not considering its importance. Start off by making sleep a priority for the next 7 days.
2. Go to bed at the same time consistently
A consistent bedtime can train your brain to switch off more easily, allowing an easier passage to deeper sleep.
3. Cut out stimulants after midday
This is an obvious one. Stimulants (surprise surprise!) keep us awake, reducing our sleep time. Again, try it for a week. Remember these include caffeine (coffee, tea, chocolate, cola, etc) and nicotine.
4. Exercise in the sunshine
Not entirely possible in all climates but if possible, this action informs your brain that it’s daytime. This, in turn, fine-tunes your body’s clock helping hormone balance and hopefully, deeper, longer sleep
5. Curtail eating and drinking 2 hours or more before bed
Cutting out bedtime snacks means you will eat fewer calories. Quality of sleep may improve and you may be more alert on waking. Drinking before bed may lead to more bathroom breaks during the night, again leading to less sleep.
6. Dim household lights at dusk
Bright white lights can trick your brain into thinking that it is still daytime and reduce the production of melatonin, the sleep hormone. Before bed, dimming the light or using amber/red bulbs can help. Also, if you do need to use the bathroom during the night, try not turning on a light.
7. Do something relaxing regularly
Choose something that will help to relax your brain and body, preparing yourself for a great night’s sleep. Think baths, reading or meditation.
8. Make things comfortable in the bedroom
Maintain a comfortable temperature, noise level and as mentioned above, brightness. In an ideal world, the room should be cool, dark, and silent, although, some find a little white noise more soothing.
9. On waking, make it bright
Switch on the lights or open the curtains the moment you wake up. This reminds your brain that it’s the start of the day and it’s time to engage.