“Beer belly”: How sleep duration affects belly fat

The beer belly has long been known as a risk factor for cardiovascular diseases. This makes it all the more important to take action against excessive belly fat, so-called visceral fat. In addition to a lack of exercise and an unhealthy diet, poor sleep is also considered to be the cause of a beer belly. This has now been confirmed by a recent study.

To do this, the international research team compared the health data of more than 5,100 women and men from the USA. They were all between the ages of 18 and 59 and took part in a survey about their eating habits between 2011 and 2014 (US National Health and Nutrition Examination Survey). The duration of sleep during the week and on weekends was also queried.

Little sleep increases the risk of beer belly

The scientists found that anyone who sleeps less than eight hours a day has a higher risk of having more belly fat. Just one hour less sleep was associated with an increase of 12.1 grams of visceral fat mass – in both men and women. However, sleeping more than eight hours a day does not appear to further reduce belly fat. Eight hours of sleep is therefore the optimum.

Other life circumstances that can also influence the amount of abdominal fat, such as calorie intake, alcohol consumption or age, were taken into account in the evaluation. X-rays were also used to examine whether, in addition to abdominal fat, the distribution of fat on the arms and legs or under the skin (so-called subcutaneous fat) changes as a result of sleep duration. However, this was not observed, explain the authors of the study.

The cause may be altered brain activity

Why a lack of sleep can lead to an increase in belly fat may be due to changes in brain activity. The authors of the study also suspect a disturbed balance of so-called neurohormones, i.e. hormones that nerve cells use for communication, as a possible trigger. However, further studies are necessary to fully understand the mechanisms and to clearly prove the connection.

This is why belly fat is dangerous

Storing a little fat is not harmful. On the contrary: body fat fulfills important functions. It insulates against cold, cushions and protects organs and is an important source of energy in times of scarce food.

However, too much fat, especially in the abdominal region, is harmful to your health . The reason: Too much visceral fat produces inflammatory substances. This can have various consequences:

• Increased risk of cardiovascular diseases such as thrombosis, heart attack or stroke due to an increase in blood pressure and an increased tendency to blood clots.
• The risk of type 2 diabetes and metabolic syndrome increases because inflammatory substances and free fatty acids (reactive components of fats) reduce the cells’ sensitivity to insulin. This leads to permanently high blood sugar levels.
• Inflammatory substances and free fatty acids reach the liver via the bloodstream. There they can influence the production of blood fats and thus lead to higher cholesterol levels .
• Visceral fat tissue produces appetite-increasing hormones, which further promotes obesity.

A waist circumference of 88 centimeters or more for women or 102 centimeters for men is considered a risk factor. You can find more information about why belly fat is so dangerous and how you can tell whether you belong to the risk group here .