For health and well-being, the quantity of sleep is essential, but a very important role is also played by the quality of sleep, especially as regards the mechanisms that regulate appetite and eating behavior. This is what emerges from a recent research published in the prestigious PNAS journal, Proceedings of the National Academy of Sciences of the United States of America, by a team from the University of Bern (Oesch et al, PNAS, 2020).
When we sleep we go through different phases including the famous REM phase, or rapid eye movement. The REM phase is a particular moment of sleep during which most dreams occur. Some areas of the brain show high electrical activity during REM phase. Among these areas that show a higher activation there is the hypothalamus, the part of the brain involved in activities like memorizing but also in the control of the body’s temperature. Not only that, when you are awake, the hypothalamus manages appetite and food intake. Therefore, in the research in question, the scientists tried to understand how the activation of hypothalamic neurons during the REM phase could then have repercussions on behavior during the day. To understand this, the researchers tried to suppress the activity of these neurons during sleep with a technique called optogenetics. In particular, light pulses were used to turn off the activity of the neurons of the hypotolamus during the REM phase in mice. As a result, the mice exhibited altered eating behavior during the day and consumed less food.
Therefore, to ensure a normal appetite and a healthy eating behavior, sleep is essential, both in quantity and quality, trying as much as possible to keep the times at which you go to sleep and wake up, to prefer a healthy diet and to avoid, in the evening hours, activities that can cause excitement.