In my last blog post, I’ve told you that I would like to eat earlier during the day to lower my cholesterol. I will try to explain it to you in a little more detail. That’s why we are today talking about your miraculous circadian rhythm or how to understand your internal clock.
What exactly is our internal clock?
Even though there are still some secrets to unravel, scientists have been able to show that all our cells follow an internal rhythm. This rhythm, as we know it from a good music rhythm, seems to be effortless, but in reality, it is an interplay of countless components that harmonize perfectly. Sometimes, however, when this harmony is disturbed, this rhythm gets out of balance and becomes unpleasantly noticeable – I am just thinking of my jet lag after my return home from Bali.
What is the internal clock responsible for?
The fascinating thing is that this rhythm is inert in every single cell, and consequently, affects every little piece of you at all times. It affects the metabolic processes in the cells and influences the hormonal system, your body temperature, your digestion, your heart, and everything else. These systems and organs influence your internal rhythm in return. An incredibly exciting and individual interaction.
Which external factors have an influence on our internal clock?
Your internal rhythm is influenced by social interactions, activity, light, and mealtimes, just to mention a few.
We can use this knowledge to our advantage. For those who are tired in the morning, for example, it might be helpful to catch some sun rays in the morning, maybe even combined with some physical activity, a short walk, or cycling to work would be ideal! Those who find it difficult to rest in the evening can try to reduce the light in the afternoon and to shift the fitness workout towards earlier the day and meditate in the evening instead.
How do the meal times affect my internal clock?
Taking into account that all cells and systems are differently active at different times, then it is not surprising that your digestion cannot be unmoved by that. Even your intestinal microbes, which live in the dark, follow a rhythm, and this influences how your body metabolizes food, for example.
Studies show that meals earlier in the day and not too late in the evening lead to less weight gain – compared to the same amounts and the same meals at a later time. Our food is in many ways very powerful and not only what and how, but also when we eat makes a big difference. For example, eating earlier can lead to lower blood pressure and cholesterol levels. Moreover, the release of hormones plays an important role in digestion, as we may know of insulin in everyday life.
Your hormones
The release of hormones also follows an internal rhythm. This process influences, for example, how well your body can digest food at a certain time of the day. As messenger substances, hormones are also formed and emitted in response to external triggers (such as stress or nutrition). To produce these nimble helpers, the right building blocks, i.e. nutrients, are required at the right time.
Let’s take insulin as an example: Part of the insulin is released according to the internal clock and another part is released depending on our meals. I think this shows the complexity and interaction of hormones and nutrition quite well.
If we fast and skip breakfast, this can be a stressful event for our bodies. This is sometimes intentional, for example with intermittent fasting, because health benefits are attributed to this stress in particular.
But for some people, this can also throw their inner clock out of kilter. Our body then sends out cortisol during the stress period in order to maximize energy despite the current low levels of nutrients.
Of course, this also affects other hormones such as cortisol, a stress hormone. So, we finally got to my lower cortisol levels.
Everybody has their own rhythm and so everybody can reach this harmony themself. But the is that it is an interplay: we are influenced by it but we can also make an impact. So it is up to us to find a loving balance.
References:
- Sehgal A. Physiology Flies with Time. Cell. 2017;171(6):1232-1235.
- Morris CJ, Garcia JI, Myers S, Yang JN, Trienekens N, Scheer FA. The Human Circadian System Has a Dominating Role in Causing the Morning/Evening Difference in Diet-Induced Thermogenesis. Obesity (Silver Spring). 2015;23(10):2053-8.
- Panda S. Circadian physiology of metabolism. Science. 2016;354(6315):1008-1015.
- Nelson RJ, Chbeir S. Dark matters: effects of light at night on metabolism. Proc Nutr Soc. 2018;77(3):223-229.
- Ruddick-collins LC, Johnston JD, Morgan PJ, Johnstone AM. The Big Breakfast Study: Chrono-nutrition influence on energy expenditure and bodyweight. Nutr Bull. 2018;43(2):174-183.
- Garaulet M, Gómez-abellán P, Alburquerque-béjar JJ, Lee YC, Ordovás JM, Scheer FA. Timing of food intake predicts weight loss effectiveness. Int J Obes (Lond). 2013;37(4):604-11.
- Beccuti G, Monagheddu C, Evangelista A, et al. Timing of food intake: Sounding the alarm about metabolic impairments? A systematic review. Pharmacol Res. 2017;125(Pt B):132-141.
- Hibi M, Masumoto A, Naito Y, et al. Nighttime snacking reduces whole body fat oxidation and increases LDL cholesterol in healthy young women. Am J Physiol Regul Integr Comp Physiol. 2013;304(2):R94-R101.
- van Someren EJ, Riemersma-van der Lek RF. Live to the rhythm, slave to the rhythm. Sleep Med Rev. 2007;11(6):465-84.
- Hower, IM, et al. 2018 Circadian Rhythms, Exercise, and Cardiovascular Health. Journal of Circadian Rhythms, 16(1): 7, pp. 1–8. DOI: https://doi. org/10.5334/jcr.164
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