This is what is called visceral fat, which is the type of fat that accumulates around internal organs (heart, liver, pancreas). Even though you might not always see it externally, it is very dangerous as it increases the risk of type 2 diabetes, heart disease, stroke, and even some types of cancer.
Why is sleep connected to belly fat?
A new study published in the Sleep Medicine journal has shown that just one hour less of sleep per night, for example, seven instead of eight hours, can cause an increase in visceral fat by 12 grams. This might sound little, but if repeated every day, the number quickly adds up. In one year, this means more than 4 kilograms of additional fat around organs, all due to lack of sleep.
The study involved more than 5100 adults between 18 and 59 years old from 2011 to 2014. The average age was 37, and participants usually slept around seven hours per night. The results clearly showed: less sleep = greater risk for a belly that is not just an aesthetic issue, but primarily a health one.
Why is visceral fat so dangerous?
Unlike subcutaneous fat that you can feel (for example, on thighs or hips), visceral fat is hidden deep in the belly. It puts pressure on organs and releases inflammatory substances that disrupt the body's balance.
Insulin resistance means that the body no longer properly uses insulin, the hormone that regulates blood sugar. This results in a higher likelihood of developing type 2 diabetes. In addition, this type of fat increases the risk for metabolic syndrome, a cluster of issues like high blood pressure, high sugar, fats in the blood, and increased body weight.
The European Society of Cardiology reported in 2025 that people who sleep less than five hours per night increase the risk of peripheral artery disease (narrowing of blood vessels in the legs and arms) by 74% compared to those who sleep seven to eight hours.
Lack of sleep and obesity – a global issue
The World Obesity Federation warned in 2023: by 2035, over half of the global population will be overweight or obese. One of the key reasons along with unhealthy diet and lack of exercise is also poor sleep.
When you sleep inadequately, the body's hormone balance is disrupted. The hormone ghrelin (which stimulates appetite) increases, while the hormone leptin (which gives the feeling of fullness) decreases. As a result, you feel hungry more often and eat more than you need. That's why after a sleepless night, people tend to reach for fast food, sweets, and energy drinks.
Sleep Quality is More Important than Quantity
Some scientists emphasize that not only the number of hours is important, but also the quality of sleep. If you sleep eight hours but wake up multiple times during the night, it is less beneficial than sleeping six hours of solid, uninterrupted sleep.
A study from 2024 showed that people with good sleep quality, meaning they fall asleep quickly, sleep deeply, and don't wake up often, maintain a healthier body weight even if they sleep slightly less than eight hours.
Folk Wisdom on Sleep
Our ancestors took sleep seriously. In rural areas, they used to say: whoever goes to bed before midnight, lives longer. And indeed, today we know it is important to follow the body's natural rhythm, known as the circadian rhythm (the body's internal clock that regulates sleep, wakefulness, and hormone function). Going to bed at the same time each night helps the body maintain balance.
Old folk remedies for better sleep included warm chamomile tea, a drink with honey, or a glass of warm milk before bedtime. Today, we would say these are natural ways to calm the body and prepare the brain for rest.
How Can You Improve Sleep and Reduce Belly Fat Yourself?
There is no need to immediately buy expensive gadgets or pills. Often, simple and inexpensive solutions are enough:
- try to go to bed and wake up at the same time, even on weekends,
- turn off screens at least an hour before sleep because blue light disrupts sleep,
- have a warm herbal tea (mint, lemon balm, chamomile) before bed,
- keep the bedroom dark, quiet, and slightly cooler,
- avoid alcohol and heavy food right before sleep.
In 2020, in Finland, 3500 people reduced phone and computer use every evening one hour before sleep. After three months, they reported a 17% reduction in belly size and better well-being, without special diets.
Why Is It Important to Take Action Now?
Visceral fat is not just a beauty issue but a serious health threat. Although it accumulates unnoticed at first, it can lead to diseases that decrease quality and length of life in the long run. Good sleep is one of the cheapest and most effective ways to prevent this.
To Sum Up: Seven hours of sleep might sound sufficient, but for health reasons, it is better to aim for eight. If you already sleep less, ensure the sleep is of high quality. And if you add some exercise, healthy diet, and folk wisdom (tea, routine, rest), you will do a lot for your body and reduce the risk of a beer belly.
Sleep as a Medicine You Don’t Pay For
In a time when people spend a lot of money on diets, supplements, and beauty treatments, sleep remains the most underrated medicine – and it's free. A well-slept night is an investment that reduces belly size, protects the heart, and strengthens the brain.
By getting enough sleep, you might truly gain what the whole world is seeking: more health, less stress, and a life without dangerous fat around organs.
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