Behind this catchy title lies an often overlooked reality: sleep is essential for our body's hormone secretion to be properly regulated, which has a strong impact on our eating behavior.
This is also a question we can ask ourselves in reverse: why does lack of sleep make us fat?
The causes
According to Dr. Joëlle Adrien, from the scientific council of the National Institute of Sleep and Vigilance (INSV), “sleeping well allows you to stay slim, while poor sleep undoubtedly makes you gain weight.” Studies conducted by the INSV demonstrate a clear link between sleep and obesity. The causes can be multiple: restless sleep (insomnia, sleep apnea, drowsiness, sleepwalking, etc.), short sleep (only 6 hours for some adults or 8 hours for adolescents) which leads to a disruption in eating behavior, or even eating rhythm.
Indeed, according to observations obtained through empirical studies, short sleepers tend to eat fewer fruits, vegetables and fish in favor of a diet richer in fats, sugars and alcohol. Added to this are also skipped breakfasts, therefore prolonged fasting not promoting regular secretion of hormones, irregular meal times, snacking, etc.
What is the link between eating behavior and sleep?
Back to the point: there are several mechanisms explaining how sleep problems lead to weight gain.
The first explanation is very simple, if we sleep less, we have more time, which also means more time to eat, especially if the tendency is to go to bed late, which favors snacking in the evening or at night.
Then, if we feel tired due to a lack of sleep, we will naturally tend to turn to more energy-dense foods to counteract this fatigue. Regular lack of sleep also increases your feeling of hunger by more than 20%, and this only from 2 too short nights per week, which is equivalent to eating the equivalent of an extra snack each day.
Added to this is the lack of activity, in fact if your body is tired, you will try to save your strength and therefore you will move less. However, the lack of physical activity is one of the main causes of being overweight.
How does sleep rhythm affect hormonal functioning?
The hormonal component also plays a role in the sleep-overweight interaction.
To simplify, during the sleep phases, our body secretes leptin, a hormone responsible for the feeling of satiety and the metabolization of fats.
During waking phases, on the other hand, our body secretes ghrelin, a hormone responsible for the feeling of hunger and giving an appetite for fatty and sugary foods.
So, if you sleep less, your body will secrete more ghrelin and less leptin. So, you will feel more hungry and want to eat fat and sugar, and in addition your fats will be less well metabolized. The lack of leptin can also lead to waking up and snacking at night due to the feeling of hunger.
Therefore, due to the reduced metabolism of fats and sugars, if you lack sleep while maintaining your eating rhythm, you will gain weight. Whereas, if you have a good sleeping rhythm, you will maintain your weight.
If you are on a diet to lose weight, lack of sleep will affect your weight loss in terms of muscle or fat. Indeed, if you lack sleep, more than 80% of the mass lost will be muscle mass, for only 20% fat mass. This will not really help you refine your figure. On the other hand, with an adequate sleep rhythm, the mass lost will be equivalent between fat and muscle, or 50-50.
Another hormone that can be disrupted by poor sleep patterns is cortisol. This hormone has an impact on abdominal obesity, so be careful to sleep well if you want to have a flat stomach.
In conclusion: sleep well to lose weight better
- Get enough sleep: your body needs an average of 8 hours of sleep for an adult, even more for a teenager
- Having a regular sleep: sleeping 5 hours on Saturday and 11 hours on Sunday will not make you catch up on your lack of sleep, set yourself a rhythm, if necessary with an alarm in the evening to go to bed, and aim for 8 hours of sleep each night
- Eat sensibly and regularly: your sleep and your hormones will help you doubly in this task
- Get regular physical activity: this will help you fall asleep better and regulate your hormonal flow, and the circle is complete.
Bonus:
To sleep well and for your sleep to be as restorative as possible, do not neglect the quality of your bedding. Indeed, the French sleep on a mattress that is on average 14 years old while the average lifespan of a mattress is 8 to 10 years.
Those who exceed this period probably do not suspect that their overused bedding is the cause of micro-awakenings and muscular tension, which does not promote good recovery.
To overcome this, here are some tips for choosing a mattress that suits your needs.
However, if your bedding is new, we have some tips to help you fall asleep better and forget about your sleep problems.
