Second Harvest Blog

Circadian Rhythm: Our Internal Clock and It’s Affect on Health, Stress, and Weight Management

By September 3, 2019 No Comments

Clocks. Not all are alike. In fact, there is an internal clock in all humans that triggers the body to perform certain functions at certain times of day.

Scientifically this system is called, circadian rhythm.  Circadian medicine, which is very new, explains how the body works with its own natural rhythms to trigger the proper times for food consumption, sleep, and exercise.

What does this internal clock have to do with nutrition? It has a lot to do with it, especially for good digestion and absorption of nutrients when eating. The body has established schedules to perform functions such as digestion and nutrient absorption at certain times of the day. If daily routines and schedules do not match the body’s schedules, an imbalance may occur which can lead to fatigue, weight gain, stress, and even illness. Speaking in terms of food only, to have proper nutrition, 50% depends on the correct choice of food and the other 50% depends on when and how it is consumed. It seems simple, but life doesn’t always stay on schedule. Making healthy relationships with food is a challenge.

The Circadian Rhythm: what it is and how it works

The internal clock resets itself every morning with daylight, every 24 hours. This clock is a system that consists of a central clock, or master clock, located in the brain. In addition, there are many peripheral clocks located in the cells, organs and tissues. The master clock works as a kind of conductor, directing many metabolic functions in the body.

The master clock is located deep in the center of the brain,  in the hypothalamus just below the optic nerve. A cluster of 20,000 neurons about the size of a grain of rice is responsible for noticing the changes of light and darkness and others cues from the environment which tells the body to perform different functions over a 24-hour period, regulating sleep and wake times. As the environment changes, this internal clock uses environmental cues to gradually reset itself.

The hypothalamus also regulates processes that we do not consciously control such as, fight or flight response, blood pressure, metabolism, hormone production, body temperature, and cell repair, among others. The skin regenerates its cells daily. Even the intestinal flora (gut bacteria) changes according to the time of the day. Therefore, there are certain times of day when the body is more efficient at processing nutrients.

The ideal is that the master clock and the peripheral clocks are synchronized. Therefore, when the brain uses light and darkness to warn the body when to eat, the digestive system prepares for the digestion of incoming nutrition. Food consumed out of the daily circadian rhythm can make it difficult to lose weight even while eating a nutritious and low-fat diet.

Eating and sleeping at the wrong times interrupts the circadian rhythm, which alters the ability to have a healthy metabolism and a powerful autoimmune response.

This system operates not only for human beings but also for all of nature and every organism in it. The behavior of animals is based on this rhythm or natural clock, they know when to wake up, when to eat, when to migrate, when to rest and when to go to sleep, and they are not bound to external clocks, compasses or cell phones.

The bottom line is the body always knows what time it is and operates Independent of external clocks that constantly dictate time.

Habits that Disrupt the Circadian Rhythm

Research on the circadian rhythm demonstrates how daily habits interact with internal natural rhythm, influencing nutrition, well-being, physical and mental health.  Some examples are:

  • Looking at TV screens, computers, and phones late at night sends misinformation to the brain that it’s time to wake up, not go to sleep.
  • Snacking too much or eating too late in the day can disrupt sleep and steal energy from the next day.
  • Lack of exercise
  • Stress

All these behaviors or habits affects the natural rhythm of sleep and wakefulness, this in turn, affects the natural rhythm of hormonal production and the job of the nervous system.

Suggestions for keeping Circadian Rhythm in time

  • For healthy digestion follow set times for important meals of the day.
  • Lunch should be the biggest meal of the day with the smallest meal being consumed at dinner.
  • If your work schedule allows, try to go to bed every night around the same time, ideally at 10:30 p.m.
  • Turn off all electronics at least one hour before bed time.
  • Shoot for seven to eight continuous hours of sleep at night.
  • Exercise during the day

This is the natural formula to reduce stress and illness, keep off extra weight, and increase energy.

It may take time to incorporate these habits into busy lifestyles, however the health benefits, both physical and mental, far outweigh the cost.