What is sleep?

Sleep is for a life of vital importance. It supports numerous physiological and psychological functions such as tissue regeneration, growth, strengthening of memory, and learning. While adults have different sleep needs, experts believe that sleep duration of continuously less than 7 hours per night could have negative effects on the brain and the body.

Sleep and the metabolism

In examining the relationship between sleep and metabolism, it is often difficult to distinguish whether certain metabolic factors affect sleep or whether the quality and length of sleep affect your metabolism. For example, more deep sleep is observed in physically active people and people with hyperthyroidism, both associated with a faster metabolism. In contrast, people do with hypothyroidism – and thus a slower metabolism – with fewer hours of deep sleep.

Reversing the correlations can be observed that sleep deprivation is associated with numerous adverse changes in metabolic activity. For example, the cortisol levels in the blood increase (this hormone is involved in stress reactions), the immune response is impaired, the body’s ability to deal with glucose decreases, and appetite control suffers. Similar changes are observed in those whose sleep structure is z. B. disturbed by young children or illness. In effect, the normal body function is disturbed due to lack of sleep, which results in the metabolism.


Does lack sleep influence health?

Laboratory tests and epidemiological studies suggest that sleep loss may play a role in the increased prevalence of diabetes and obesity. When the correlation between the lack of sleep, weight gain, and the risk of diabetes may play a role change in glucose metabolism, increased appetite, and decreased energy consumption Spielen.1

Sleep and glucose metabolism

Shorter sleep stages are associated with impaired glucose tolerance with increased cortisol concentration in the blood. The term glucose tolerance describes how the body controls the distribution of glucose between blood and tissue. High glucose concentrations and the hormone insulin in the bloodstream in the fasted state indicate that the body does not adequately deal with the glucose. It has been proven that low glucose tolerance is a risk factor for diabetes type. 2 According to the research can cause a 40% drop in the glucose tolerance of long-term sleep loss (<6.5 hours per night).

Increased appetite

There was a correlation between habitual short sleep time and increased body mass index (BMI) reported in large populations. Short sleep was associated with hormone levels that control hunger: leptin levels (appetite-reducing) were low, while ghrelin (appetizing) was high. These effects were observed when the sleep time was under 8 hours fiel.1,3 This suggests that sleep deprivation is a risk factor for obesity. In a controlled study in healthy male volunteers, a sleep duration of about 4 hours with a significantly higher demand for high-calorie foods with high carbohydrate content (sweets, salty and high-starch diet) was associated. It was also about reported. Two stronger feelings of hunger

A shorter sleep time, more time for eating and drinking are available, and some research findings suggest that this is a factor that contributes to the development of obesity in combination with short sleep phases.

Reduced energy consumption

To mention the other side of the energy balance – it is less likely that people are physically active with sleep deprivation, resulting in reduced energy consumption.

In summary, the increase in appetite and desire for food and the reduction of physical activity represent a quick-witted argument for the role of sleep in handling body weight.

The vicious circle of disordered sleep and obesity

The disorder, sleep apnea, affects about 24% of men and 9% of women. It is characterized by pauses in breathing during sleep, disturbed sleep, and daytime fatigue result. There is a strong link between this disease and obesity. Studies have shown that people with sleep apnea experience abnormal sleeping patterns that could exacerbate the problems associated with sleep deprivation metabolic disorders (e.g., increased hunger). It might accordingly the induced by obesity sleep apnea syndrome, in turn, influence appetite, and energy consumption, and in a way that promotes obesity. To fully understand the relationships, further research is needed.



The lack of high-quality sleep appears to impact physiological mechanisms of energy balance, namely appetite, hunger, and energy expenditure. Furthermore, sleep deprivation hurts the ability of the body to handle glucose. It may increase the risk of diabetes mellitus type. 2 It is not yet clear to what extent changes in sleep patterns could be used to create a favorable environment for the handling of body weight and for reducing the risk of related diseases.