Why a lack of sleep is making us fat


People who are sleep deprived are putting themselves at risk of being overweight as well as tired.
A new study which analysed existing data found that not getting enough sleep makes us consume nearly 400 more calories the following day.
Not getting enough rest also makes us choose less healthy food.
Study author Gerda Pot, who is a lecturer at the Diabetes and Nutritional Sciences Division at King’s College London said over the course of a number of years, all of those calories could add up, adding inches onto our waistlines.
She said: “If long-term sleep deprivation continues to result in an increased calorie intake of this magnitude, it may contribute to weight gain. And ultimately to obesity and [being] overweight.”
The research looked at information from 172 people taken across 11 earlier studies. It looked at how a lack of sleep affected calorie intake.
On average, the new study found that those who had not enjoyed a proper night’s sleep ate an additional 385 calories the following day.
The research team looked at nights when they had slept for 3.5 to 5.5 hours, compared to days when they had had at least seven hours’ sleep.
As well as consuming more in terms of calories, those who were lacking in sleep also tended to eat more fat and less protein.
Professor Pot said there were a number of reasons why we could be eating more if we were sleep deprived. The most simple explanation was that because we are awake for longer, we have more hours available to us to eat.
Another reason could be that having too little sleep can mean the body produces more ghrelin, which is the hormone responsible for telling us when we are hungry, and less leptin, the hormone which tells us when we are full.
A lack of sleep also affects our circadian rhythm which helps us to regulate waking and sleeping patterns as well as when we’re hungry and when we eat.
Researchers believe that the 400 calories may actually be an underestimate because they do not look at real life factors, such as fancying sugary snacks, or perhaps eating chocolate or drinking an energy drink in a bid to feel more awake.
Whatever the reason behind it though, the researchers did show a direct correlation between not sleeping enough and eating too much.