Sleep is arguably the second most important factor in health and metabolism, besides nutrition. Its hormonal effects are very underrated. We usually focus on nutrition and exercise in the weight-loss and lifestyle-transformation process. But lack of sleep can mess up our well-planned weight-loss project. Lack of sleep or poor sleep quality is one of the most important risk factors for many diseases like cardiovascular diseases, dementia, and cancers. A good example of this is night shift workers. A meta-analysis done in 2018 found that the more night shifts a person works, the greater their risk of developing type 2 diabetes. The risk of diabetes for night shift workers is up to 44% higher than for those who only work day shifts. The other thing that a motivated dieter doesn’t know is that just losing a couple of hours of sleep every night sabotages his/her weight loss process in a rather extreme way. In another study, it was found that while sleeping either 5.5 hours or 8.5 hours a night, both groups lost the same amount of weight. The 5.5 hour group lost 55% less fat and 60% more fat-free mass than the 8.5 hour group. This has an enormous effect on one’s weight loss goal and metabolism in the long run. It is no wonder that our western society has so many chronic diseases, when it is estimated that 75% of adults don’t sleep enough.
Biological circadian rhythm
Our need for sleep and its effects on our body come down to our biology as animals. The human brain and metabolism has developed a way to cope with daytime light and nighttime darkness over millions of years. This means we are meant to be active and search for food during the daytime and be inactive and without food during the dark hours. Sleep is actually a very delicate and complex process, which can be affected by many factors that affect this cycle. Those could be:
- Feeding rhythm
- Daily activities and their rhythm (and regularity)
- Exposure to blue light through technology
- Exposure to sunlight
- Medical drugs, alcohol, and other substances
- Chronic diseases, as for some examples
But maybe the most important thing that affects our sleep, and thus disturbs our metabolism, is irregular sleep patterns. We so often stay awake too long, worse yet — behind blue light emitting screens, and wake early for the work day. At the same time, we stay awake even longer on weekends and sleep till the afternoon the next day. Our brains have no way to control our bodies hormonal levels and autonomic nervous system since there is no apparent regularity in our sleep cycle. It is really much more than just feeling a little sluggish the next day. Chronic lack of sleep causes:
- Appetite problems — often lack of hunger during the morning/daytime and unsatisfiable hunger in the evenings
- Loss of willpower, one feels unmotivated and gives in to temptations
- Emotional eating
- Problems with memory and learning things
- Slowed reaction time — basically it’s like driving drunk
- Lowered physical performance
- Unstable mood, irritability
One doesn't need to be a doctor to see how big of an impact sleep has on our health, nutrition, and weight.
This was our very short overview of the importance of sleep. In the next chapter we will focus on the practical side — how can you sleep better?