Does a bad night's sleep make you likely to overeat?

January 6, 2014 by Charlotte Hardman, The Conversation
Being tired is linked to eating unhealthy foods that may cause weight gain. Credit: Shuttershock

Few people would argue with the idea that sleep is good for us, but not many of us know that a lack of sleep can cause weight gain.

The health benefits of sleep are extremely well-documented. It provides protection from many medical and psychiatric conditions as well as having positive effects on mood, quality of life and well-being.

But more recently, mounting evidence has suggested that poor sleep is associated with an increased risk of obesity.

Short sleep duration appears to predict changes in weight over time. Children who were poor sleepers at three years of age, for instance, have been found more likely to be obese by the age of seven.

Sleep and brain function

While there are a number of possible explanations for the relationship between poor sleep and obesity, there's growing support for the idea that disrupted sleep increases food intake. This may be due to the effect of sleep deprivation on and the physiological control of appetite.

Some studies, for instance, indicate that short sleep duration increases levels of the gut hormone, ghrelin, which makes us feel hungry and often leads to increased eating.

Poor sleep might also increase the reward value of eating by making certain foods seem more attractive and increasing our motivation to obtain them. This idea is supported by recent research using functional magnetic resonance imaging (fMRI), which measures activity in specific regions of the by detecting changes in blood flow.

The study found that, in people with limited sleep, the brain regions associated with reward "lit up" more in response to pictures of tasty food, suggesting that sleepy people found these foods more appealing.

Sleep deprivation often leads to cravings for high-calorie food. Credit: Wikimedia Commons/Christian Razukas

At the same time, might also impair our ability to make decisions and exert self-control over .

In another recent brain imaging study, 23 healthy people had a night of normal sleep and a night of total sleep deprivation followed by fMRI scans.

After sleep deprivation, there was greater activity in the amygdala region of the brain (which is important for reward behaviour) in response to pictures of food. Sleep-deprived participants also reported a greater desire specifically for high-calorie foods compared to low-calorie foods.

At the same time, the scans showed other regions of the brain believed to be important for "higher-level" brain function and self-control were less active after sleep deprivation. This means sleepy people may be less able to control what and how much they eat.

So it seems sleep deprivation may promote over-eating via a two-pronged effect on brain function – the desirability of food is increased at the same time as higher-level processes that enable us to control how much we eat fail.

Understanding self-control

The idea that reduces our ability to inhibit certain behaviours also appears to make sense in the context of more general theories of self-control.

The Limited Resource theory, for instance, proposes that we have a finite reserve of self-control that can be used to regulate our behaviour, similar to a muscle that becomes fatigued under too much pressure.

When you are tired after poor sleep, you might have reduced self-control "strength", making you more likely to engage in disinhibited behaviours, such as over-eating unhealthy foods.

Indeed, a longitudinal study found over-tiredness in childhood predicted lower inhibitory control in adolescence which, in turn, predicted illicit drug use.

The next step for this line of research is to illustrate whether these findings apply to excessive consumption of food.

There is, in fact, growing evidence that poor inhibitory control is a critical factor in over-eating, along with other substance use disorders.

But it's important to consider alternative mechanisms that might account for the association between sleep, eating and obesity such as the dampening effect has on mood. After bad sleep, we may feel fed up or depressed, which might promote the eating of high-calorie "comfort foods".

Research in this area provides important insight into the causes of over-eating, obesity and potential intervention strategies. Helping people to improve the length and quality of may be one such approach.

Explore further: Sleep to protect your brain

Related Stories

Sleep to protect your brain

December 31, 2013
A new study from Uppsala University, Sweden, shows that one night of sleep deprivation increases morning blood concentrations of NSE and S-100B in healthy young men. These molecules are typically found in the brain. Thus, ...

Sleep deprivation increases food purchasing the next day

September 5, 2013
People who were deprived of one night's sleep purchased more calories and grams of food in a mock supermarket on the following day in a new study published in the journal Obesity, the official journal of The Obesity Society. ...

Study explains how sleep loss can make you fat

August 6, 2013
A sleepless night makes us more likely to reach for doughnuts or pizza than for whole grains and leafy green vegetables, suggests a new study from UC Berkeley that examines the brain regions that control food choices. The ...

Brain scans show specific neuronal response to junk food when sleep-restricted

June 10, 2012
The sight of unhealthy food during a period of sleep restriction activated reward centers in the brain that were less active when participants had adequate sleep, according to a new study using brain scans to better understand ...

MRI scans show how sleep loss affects the ability to choose proper foods

June 10, 2012
MRI scans from a study being presented today at SLEEP 2012 reveal how sleep deprivation impairs the higher-order regions in the human brain where food choices are made, possibly helping explain the link between sleep loss ...

Researchers link sleep deprivation with criminal behavior

November 22, 2013
Lack of sleep can contribute to delinquent behavior by adolescents, according to an FIU study published earlier this month.

Recommended for you

Who uses phone apps to track sleep habits? Mostly the healthy and wealthy in US

January 16, 2018
The profile of most Americans who use popular mobile phone apps that track sleep habits is that they are relatively affluent, claim to eat well, and say they are in good health, even if some of them tend to smoke.

Improvements in mortality rates are slowed by rise in obesity in the United States

January 15, 2018
With countless medical advances and efforts to curb smoking, one might expect that life expectancy in the United States would improve. Yet according to recent studies, there's been a reduction in the rate of improvement in ...

Teens likely to crave junk food after watching TV ads

January 15, 2018
Teenagers who watch more than three hours of commercial TV a day are more likely to eat hundreds of extra junk food snacks, according to a report by Cancer Research UK.

Can muesli help against arthritis?

January 15, 2018
It is well known that healthy eating increases a general sense of wellbeing. Researchers at Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) have now discovered that a fibre-rich diet can have a positive influence ...

Your dishwasher is not as sterile as you think

January 13, 2018
(HealthDay)—Your dishwasher may get those plates spotless, but it is also probably teeming with bacteria and fungus, a new study suggests.

Study reveals what sleep talkers have to say

January 12, 2018
A team of researchers with members from several institutions in France has conducted a study regarding sleep talking and has found that most sleep talking is not only negative in nature, but involves a large amount of swearing. ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

RobertKarlStonjek
not rated yet Jan 07, 2014
One of the confounders of these studies is the possible difference between the effects of a change of sleep regime. What effect does changing one's sleep pattern have?

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.