Melatonin: how do sleep hormones affect our weight?

Melatonin & Co: Wie Schlafhormone auf uns wirken Melatonin & Co: Wie Schlafhormone auf uns wirken

Slim while asleep – an attractive thought. But how should we understand this statement? The fact is that while we sleep, certain hormones are particularly active. Melatonin is one.

Sleep deficit can cause excess weight

The amount we sleep and our sleep quality have an impact on our body weight, as several studies show. People who sleep more develop less excess weight. On the other hand, that doesn't mean that people who sleep little are necessarily overweight. However, it’s a fact that sufficient sleep has a beneficial effect on our weight.

There's a certain logic to this theory: those who are awake longer have more chance to eat, and, because they are tired, are more likely to skip the workout originally scheduled. But these reasons alone aren't enough, because it's our hormonal levels that regulate our weight – and it is hormones that influence whether we are hungry, full or have a craving for sweet foods.

Sufficient sleep has a bene­fi­cial effect on our weight.

Sleep hormones regulate appetite

Sleep changes our appetite levels. This is because a lack of sleep causes the body to release the hormone ghrelin. This stimulates our appetite, steering our feeling of hunger and satiety. At the same time, less of the hormone leptin is released. This is the hormone that tells our brain when we are full. In short, people with little sleep tend to have a greater appetite and a limited feeling of satiety.

The stress hormone cortisol and sleep

But it doesn't stop there. There's also the stress hormone cortisol. This enables the body to provide energy quickly and activate vital functions. While asleep, the body doesn't normally release cortisol until the morning. However, if – due to stress and sleep disorders – the cortisol concentration remains high, the opposite happens: the body builds up fat reserves.

Melatonin: helping us sleep well

Melatonin is probably the hormone most commonly connected to sleep. It is mainly released by the pineal gland when night falls, ultimately making us tired and enabling us to sleep well. And even though it isn't directly linked to our feelings of hunger or satiety, melatonin affects our sleep – and, as we have seen, the amount and quality of sleep we get has a distinct impact on our weight. In order to stimulate sleep-inducing melatonin, it’s advisable not to look at screens or smartphones before going to bed.

Slim while asleep?

It’s not quite that easy. Even if the solution «slim while asleep» doesn't tell the full story, there is indeed a connection between sleep and body weight – and hormones play a key role in the process. And, for the body to produce these hormones, not only the length of our sleep but also the quality are important. Sleep quality is a feeling that depends on the individual – feeling refreshed is what counts. Research says that less than 6 hours of restful sleep can lead to obesity and related diseases like diabetes mellitus and high blood pressure. Viewed in the long term, we should aim for at least 6 hours of sleep per day.

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