What is sleep?
Sleep is considered a normal state characterized by reduced perception and limited interaction with the environment. We know a lot about the benefits of sleep, such as clearing our brain from various metabolic by-products that accumulate during the day (1). We also know the negative impact of sleep deprivation. But before we get there,
"What exactly do we measure in sleep?”
Usually we monitor sleep either by checking its architecture - that is sleep stages - or by recording sleep duration and continuity (2). Generally, there are 4 sleep stages: the N1 and N2 stage (we usually refer to them as “light sleep”), the N3 sleep stage (often referred to “deep sleep”) and the REM (Rapid Eye Movement) sleep stage. During REM stage there is a stimulation of various physiological systems of the body (for example we are dreaming during REM). On the other hand, when we refer to sleep efficiency, we usually refer to sleep duration sleep, the amount of time it takes us to fall asleep or even if we wake up during sleep.
“How can diet affects sleep?”
There is evidence that certain eating habits can make us sleep better (3). There are also many nutrients associated with an improved sleep routine, such as magnesium (4). In addition, there are a accumulative number of studies that show a strong relationship between sleep and dietary carbohydrates consumption.
In a very recent study we published, we showed that low carbohydrate intake seems to increase the amount of deep sleep, while increased carbohydrate intake increases the amount of REM sleep (3).
Nevertheless, differences in carbohydrate consumption do not vary only among the amount of carbohydrates we consume, but also in the type of carbohydrate we eat.
Briefly, there is an indicator called “glycemic index”, that shows us how fast blood sugar rises after eating a food. The higher the glycemic index, the faster the blood sugar rises.
Towards this direction, in another study, we found that prescribing individuals with a high-glycemic carbohydrate meal after an afternoon workout led them to sleep more and with improved efficiency, compared to the control group that consumed and identical but with low-glycemic index carbohydrate meal(5).
Why should I improve my sleep routine?”
This is because insufficient sleep:
- Is related to depression (6).
- May lead to reduced problem solving ability (7).
- Is related to metabolic syndrome and increases insulin resistance (8).
- It seems to increase hunger (9). In fact, this effect on hunger may be even more intense when sleep deprivation is combined with a diet to lose weight.
“Realy? Does insufficient sleep affect my weight?”
In a study in 2010, (10), researchers investigated the following scenario: They prescribed a hypocaloric diet to 10 people who aimed to lose weight. The diet was individualized for everyone but with the same caloric deficit in everyone. This means that all subjects should have similar weight-loss rate. The subects would follow this diet for 4 weeks and here is the interesting thing: During two weeks of these 4-week periods, subjects could sleep 8.5 hours, while during the other two weeks, only were allows to sleep only 5.5 hours.
-What were the results?
At the end of the study, it was found that the subjects lost exactly the same weight with either 8.5 or 5.5 hours of sleep. Three kilos.
Disappointing? No.
During the two weeks that they slept 8.5 hours they lost 1.4 kilos of fat, while in the two weeks that they slept 5.5 hours, they lost only 0.6 kilos of fat. Of course, the exact opposite happened to their lean mass, which decreased when participants slept for only 5.5 hours. So yes, during two weeks of diet, with or without enough sleep, you will lose exactly the same weight. However, the body composition will be shaped completely differently even in short-term.
“Please help me sleep better”
That’s what we are trying to do in Dietitico either ways. We try to help you improve your quality of life, so there you are.
