The circadian rhythm keeps our bodies functioning correctly, dictating the timing of all vital and natural processes to keep our bodies balanced and healthy. One example is sleep, which plays a crucial role in our health because our brains and bodies mainly repair when we sleep, so a disrupted sleep pattern will harm the regenerative process.
There is an essential link between sleep and nutrition. Not sleeping enough impacts our ability to regulate our emotions, appetite and food choices, increasing the likelihood of overeating and consuming unhealthy foods. On the other hand, poor food choices during the day may affect how well we sleep. Understanding the connections between sleep and nutrition creates opportunities to optimize to eat smarter, sleep better, and live healthier lives.
Let’s get started!
Let’s talk about circadian rhythms.
Circadian rhythms are physical, mental, and behavioural changes that follow a 24-hour cycle. Different body systems, such as the digestive, circulatory and immune systems, follow circadian rhythms synchronized with a master clock located in a part of the brain called the hypothalamus; these natural processes respond to exercise, social activity, and temperature, but the light is the most potent influence on circadian rhythms.
The clocks react to cues such as food or light and communicate with one another throughout the day to decide what to do. For example, if there is light, the master clock will send a message to all the clocks to “wake up is time to be active” if it is dark, it will be more like” chill out and yoga time”, but if we are under stress at night time, the clock will send a message to “stay awake and alert” making it harder for our bodies and mind to relax and prepare to rest. Unfortunately, our modern life has provided us with many sources of stress and artificial light, like television and smartphones. Of course, this also has many positive advantages, such as helping us connect. Still, it also emits high-intensity blue light that gets misinterpreted as daylight, affecting our natural sleep patterns.
Exposure to light at night perturbs the circadian system because the light is the primary entraining cue used by the body to discriminate day from night.
The problem?
When our exposure to light is nearly constant, biological and behavioural rhythms can become desynchronized, leading to adverse mental and physical health consequences. Based on these messages, your brain sends instructions to produce or suppress your body’s sleep-promoting hormone, melatonin. When our sleep is compromised, or we experience sleep disturbance, this will negatively impact our hormonal rhythms and metabolism. Also, this is associated with obesity, insulin insensitivity, diabetes, hormonal imbalance, and appetite dysregulation.
The connection between sleep and overeating
As we saw before, sleep disturbance will negatively impact hormonal rhythms; balanced hormones are vital not only for a healthy body but also for a healthy mind because hormones control metabolism, mood, reproductive function, and sexual health, furthermore; this disruption to average hormone production is a driving factor behind sleep deprivation leading to overeating.
The hormones leptin (related to feeling full) and ghrelin (related to hunger) are both integral to hunger, so when the natural rhythm of these two hormones is compromised, appetite signals may also be affected. For example, lack of sleep increases levels of ghrelin and decreases levels of leptin, affecting parts of the brain that determine how we think about food; In other words, it makes us more hungry and vulnerable to overeating.
At the same time, overeating can affect sleep. Because apart from making you feel too full, big meals may cause and increase acid reflux production, affecting good quality sleep. But it is not only about how much or what you eat; timing matters too. For example, eating close to bed will increase the changes in acid reflux, and negativity impacts metabolism.
How to maintain a healthy circadian rhythm?
The reality is that we do not have 100 per cent control of our rhythm. Still, despite this, life often brings situations in which we cannot avoid many things that make the circadian rhythm out of balance, such as eating too late at night, working night shifts or not sleeping enough at night. However, there can still do many things daily to keep a healthy circadian rhythm and prevent unhealthy side effects.
Healthy habits
1) Sun exposure first thing in the morning. Exposure to natural light, especially early in the day, helps reinforce the most vital circadian cue.
2) Keep good sleep hygiene. Maintaining a consistent sleep schedule is crucial for your body to understand when it is time to sleep and when it is time to wake up.
3) Exercise and movement during the day help make it easier to fall asleep at night and contribute to your overall health, so move that body.
4) If you take a nap, keep them short, no longer than 30 minutes, to avoid disrupting your sleep in the evening.
5) Avoid caffeine after 2:00 pm.
6) Consume most of your calories during the day and eat your last meal at least two hours before bedtime.
7) Limit blue light before bed (at least an hour before bedtime) i strongly recommend you get a pair of blue blockers if you need to work late in the evening or want to watch tv.
8) Reduce stress levels, especially before bedtime.
(For more about sleep, go to my five tips for a better sleep article)
Bottom line:
Unfortunately, circadian rhythm disruptions are common in our modern society, with most people eating late meals, checking social media before bed, and working at night. Whatever you are dealing with, overeating or not keeping a healthy circadian rhythm and sleep hygiene is crucial for your body processes and overall health. So take sleep seriously and get blue-blockers glasses already!
Resources:
https://pubmed.ncbi.nlm.nih.gov/25450058/
https://pubmed.ncbi.nlm.nih.gov/22357722/
https://pubmed.ncbi.nlm.nih.gov/15583226/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3763921/
https://pubmed.ncbi.nlm.nih.gov/22259064/
https://pubmed.ncbi.nlm.nih.gov/25861266/
https://www.nature.com/articles/s41398-020-0694-0
https://www.nature.com/articles/s41398-020-0694-0
https://pubmed.ncbi.nlm.nih.gov/11583769/
