Time Restricted Feeding


Virtually every living organism on the planet has an internal biological clock that helps them anticipate time. New research now indicates that these internal circadian clocks that respond to light also respond and are affected by the consumption of food. These clocks are located not only in the brain, but throughout all the organ systems of the body.

Every major organ in the human body has a circadian clock that tells the organ when and when not to be active. Over time these clocks become wired together. In other words these biological time clocks are synchronized genetically as one complete circadian system that play an enormously important role in how our physical body and conscious mind operate as one in the continuum and dimension we know as time.

We know that the body’s circadian clock is connected to our sleep-wake cycle. The suprachiasmatic nucleus, located deep within the hypothalamus, is the master pacemaker of circadian rhythms.

Module Five of the CSNA Education Program reviews over a dozen different Body Types. One of these is called Chronotype.

Chronobiology is a new and relatively unknown science. It includes the investigation and study of rhythmic patterns established in biological or living phenomena. These patterns influence our mood and emotions, as well as our strength, speed and athletic ability.

In addition to identifying the cause and nature of these rhythmic patterns which generally occur in cycles, Chronobiology attempts to understand the influence of these patterns on physiological, psychomotor, cognitive and psycho-emotional functions.

Genetic predisposition, lifestyle, age and nutrition influence these rhythmic patterns, thus there is great variation in individual chronotype among different cross-sections of people.

Every pattern established within a living organism is a function of homeostasis. Balance of mind and body is maintained in cycles that rise and fall like the sun and the moon, and fluctuate back and forth like the ebb and flow of the ocean’s tide.

Energy levels, mood, digestive function, memory and hunger all express themselves with differences in terms of intensity and quality, but they tend to follow definite, rhythmic patterns. Certain moods tend to vary day by day. One morning you feel strong and can’t wait to get to the gym. The next day you feel sluggish and as evening approaches your energy fades and motivation to train is diminished. Why?

It has been said that “timing is everything”. Planning events in unison with our chronotype appears to be a reasonable concept. This includes developing a training schedule that works “with” rather than against inherent patterns established by our sleep-wake cycle, which is the principle driving force behind chronotype.

One specific subset of chronotype is defined by circadian rhythm. Circadian rhythms regulate biological cycles in 24-hour intervals.

Our sleep cycle takes approximately 90 minutes to complete, thus it is defined as an ultradian cycle. Ultradian rhythms are defined by cycles that occur in 20 hours or less.

Infradian rhythms are defined by cyclic patterns that recur over periods in excess of 28-hours. Patterns of infection, colds or depressed immune function represent seasonal patterns or infradian rhythms that vary consistently throughout the year in certain individuals.

So we’ve got circadian, ultradian and infradian cycles.

These chronobiological patterns function like a river running through us with a definite direction in current, and as this internal river changes in speed and direction, it often overrides the “best laid plans of mice and men”. Nature is no respecter of persons.

Although our intentions are good, on certain days, or in a certain portion of the day, our energy and motivational state may not pan out according to our expectations and conscious desires. And now we know why.

Our circadian clock is controlled both by light and by eating. From the moment we take our first calorie our metabolic clock begins to tick. A cascade of biological waves occur in very precise sequences. Research has shown that eating at an inappropriate time during this clock cycle leads to health outcomes that are definitely less than ideal.

Dr. Satchin Panda at the Salk Institute has discovered that each organ in the body including the brain possesses a unique biological clock. These clocks are affected not only by what we eat but also when. Evidence suggests that due to environmental influence and genomic factors humans are better suited to consume food within a 12 hour period beginning after our first exposure to food or drink in the morning.

Melanopsin cells in the eyes act as light receptors and set the clock after we receive our first exposure to light. Melanopsin serves an important role in the photoentrainment of circadian rhythms in mammals. An organism that is photoentrained has aligned its activity to a 24-hour cycle, which is the same as the solar cycle that we all experience here on Earth.

In mammals, the eye is the main photosensitive organ for the transmission of light signals to the brain. However, what’s interesting is that blind people are still able to entrain to the environmental light-dark cycle, despite having no conscious perception of light.

One study exposed subjects to bright light for a prolonged duration of time and measured their melatonin concentrations. Melatonin was not only suppressed in visually unimpaired humans, but also in blind participants, suggesting that the photic pathway used by the circadian system is functionally intact despite blindness.

In the evening most of us experience an extended period of light with the help of electricity. Exposure to artificial light in the evening sends a message to the brain that it’s daytime. Melatonin release is inhibited. Melatonin production depends on bright light exposure throughout the day, but it is only released in the absence of light.

In relation to the concept of time restricted feeding, we know that genetically-wired circadian organ clocks respond to food in a similar way to how the brain responds to light. The food tells our organs when to time their activity. For example, when we eat instructs the liver clock when to turn on certain genes and when to turn them off. These genes influence the outcome of our biology, health and performance.

Organs like the pancreas, heart and spleen respond metabolically to when we eat. The first sight of bright light and the first morsel of food both determine how our circadian body clocks work.

Time Restricted Feeding research is based on the notion of eating within a distinct period of 12 hours beginning from the moment we consume our first bite up until the time we consume our last.

Eating within a 12 hour period has been shown reduce fat mass, increase lean muscle mass, lower inflammation, improve heart function with age, increase mitochondrial volume, activate ketone body production, improve the process of tissue repair and improve anaerobic endurance.

So it appears that WHEN we eat really does matter. The best time restriction period for health and the prevention of disease is a maximum of 12 hours starting from our first bite of food, coffee or protein shake.


This means pretty much anything with an energy signature. It also means that we shouldn’t eat at night after dinner as many of us do for a host of different reasons.

But the concept of not eating at night isn’t new. In fact I remember learning first of this principle from Dr. Paavo Airola in 1975, from his book How To Get Well. Dr. Airola called it systematic undereating. He recommended eating small meals throughout the day and fasting after 6pm on water and herbal teas.

This strategy he claimed prevents the accumulation of excess body fat, and in most cases stabilizes blood sugar and improves sleep. Loading up on junk food at night is definitely not a healthy habit and should be avoided.

Although when we eat certainly matters, let’s not forget the importance of food quality. Eating the right food at the right time is a terrific way to stay well and prevent chronic degenerative disease.

Rodents feed a deplorable SAD diet but limited to a 12 hr period of time, fare better metabolically than rats allowed to eat anytime and randomly over a 24 hour period, even if the food is wholesome. However, rodents fed a high quality whole food diet but limited to a 12 hr period of time, fare the best metabolically and functionally when compared to all other groups and subjects.

Chronotyping is an exciting new way of assessing individual response to light, exercise and nutrition. Call it environmental nutrition. It helps us to establish ideal training and feeding times and this insight can improve adherence to exercise, improve our athletic performance and minimize potential risk or damage to muscle tissue, joints or the heart.

Chronobiological science should remind us about our connection to the earth and our environment.

It provides evidence that specific rhythms and patterns flow through us like how the Colorado River weaves and turns its way through the Grand Canyon. I was just there and it’s a sight to behold.

Yes, we can ignore these rhythms and resist for a time...and in the short-term we might even experience the illusion of dominance, independence and control. But in the long run, “resistance is futile” because simply put and like it or not, Nature is a Dictator.


“If you truly love nature, you will find beauty everywhere.”

~ Vincent Van Gogh



As always...Stay Well and Live Free!

Dr.C


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