When Nerys was first born she was really quite a good sleeper.
Then we hit the four month sleep regression and oh my word did it all go to pot. For months and months she woke through the night. Sometimes she would sleep for 2 or 3 hour stretches. Other nights she would wake every hour.
And I was exhausted.
And I ate really badly.
I found myself craving sugary junk food all the time. And pretty much all the time I gave in to those cravings. I dread to think how many biscuits and pieces of cake I ate that year.
Now Nerys sleeps much better, but I’m still disturbed by my children at least once every night. That combined with late nights writing and editing photos means I’m still pretty tired these days. And I still eat more junk than I should.
But, I’ve found something that makes me feel a bit better about it.
I’ve done some research and found out the reason why we eat more junk when we’re sleep deprived.
Sleep deprivation does some pretty wacky things to you.
It can make you forgetful. It can make you clumsy.
It can even make it hard for you to show positive emotions on your face, or recognise positive facial expressions on others!
What it also does is make it harder for you to control cravings for junk food.
Part of it is hormonal. Lack of sleep has been linked to an increase in the peptide ghrelin, which stimulates hunger, as well as a decrease in leptin which is the thing that lets our brains know that we’re full.
Part of it is a need for energy. And we go for chocolate and sugary foods to get that energy hit as quickly as we can. Blame evolution for that one.
And part of it is good old psychology. Research by Greer et al in 2013 found that lack of sleep reduces our self control. The researchers scanned the brains of 24 people after both a good night’s sleep and a bad night’s sleep.
They found that after a bad night there was increased activity in the areas of the brain that are associated with rewards. And there was reduced activity in the frontal lobes, which is the part of the brain that helps provide self-control.
The researchers explained:
“What we have discovered is that high-level brain regions required for complex judgments and decisions become blunted by a lack of sleep, while more primal brain structures that control motivation and desire are amplified.”
Basically, when we’re sleep deprived we just don’t have the amount of self-control we would normally have. And we don’t make the best decisions when we’re tired either. A study that was carried out in Sweden in 2013 found that men who went food shopping when they were sleep deprived bought around 9% more calories than those who had slept well.
I don’t know about you, but that makes me feel a bit better about all the biscuit binges. It’s really not my fault when I’m tired, I genuinely can’t help myself!