Cephalic Phase Digestion Response


“I am drooling”! We have all heard and maybe used this phrase many times, both literally and metaphorically. The realization, however, of how deeply attached this phrase is to our biology, could change our attitude towards food and the process of eating. In fact, the optimization of the inner biological mechanisms behind this process is a key element of our mind-body eating coaching.

What we are talking about is something known to the scientific community as “Cephalic Phase of Digestion Response”. I know, you’ve never heard of it. It’s mostly unknown to the general public.

Let’s see what this means and how it affects us. In the old days, we believed that food digestion started as soon as food reached the stomach. Later, we found that there are glands in our mouth, which secrete enzymes that initiate the breaking-down of carbohydrates. The simplest of all carbohydrates, table sugar, is completely broken down inside our mouth and absorbed directly by the body; we do not have to digest it further. But for some time now, we also know that the digestion process begins even before any food comes into our mouths.

When the image of food that we are about to eat forms in our mind, the brain gives the body the command to start preparing for the digestion process. In other words, the brain processes and cognitively senses the image and the smell of food, instructing that the appropriate gastric fluids and enzymes start to flow in our digestive system. One of these preparatory actions, indeed, is to activate the salivary glands, so we start to drool!

What’s noteworthy here, is that during the cephalic phase, between 20% and 40% of the total enzymes and digestive fluids that will be required for the complete digestion process are secreted. Take a moment to ponder on that percentage. It’s huge! In a sense, almost half of digestion is done before we even start eating! In addition, while we eat, the brain analyzes the color, appearance, texture, flavor, and taste of the food, “consulting” with the Enteric Nervous System (ENS)  on the correct digestion of ingredients. Have we taken in enough fat, enough carbohydrates, enough protein, enough water, enough micro-nutrients? Do we need more digestive enzymes? Do we need to make the stomach more acidic or less acidic?

And something “magical”: the Cephalic Phase takes place only when we eat food that we enjoy! More specifically, how well we metabolize the food we eat is depended directly on the pleasure and enjoyment that we get from eating; when we eat something we do not like, a mild (or not so mild) stress response is activated, which makes the digestive system slow down or even stop working! There’s research on the subject at least since the 2000s: Food_that_Tastes_Good_is_More_Nutritious

Those among the readers who are parents, please take a moment to go over that last paragraph once again, before going any further…

Read it? OK. Now, are you familiar with table conversations that go like “you will eat it because it’s good for you”, “no, I do not like it”, “you’re not getting up from the table until you finish your dish”, “I don’t want to, I’m not going to eat it”? Well, let me break some news to you. For someone who is eating under stress (and being forced to eat something we don’t like does create stress), their digestive system shuts down and it stops absorbing nutrients, almost entirely. It’s a perfectly normal side-effect of the fight or flight stress response. May it be a super-duper superfood – makes no difference; if in stress, the human body will barely absorb any of its nutrients. Who knew! A superfood eaten under stress becomes equivalent to junk, little more than empty calories!

It would be much more pleasant, and much more beneficial, to be playful with food; to try alternatives – different foods with the same basic nutrients, or the same foods, but cooked differently; anything, as long as the food in our plate becomes something that we’d enjoy eating! Our goal must be to cultivate (within ourselves and in those around us) the natural instinct of recognizing what the body needs and how to experience the joy of eating.

And that brings us to another hugely important issue: being present during our meals. This means that while we eat, we must be consciously present, with our attention focused on all of our physical senses involved in eating: we see the food, we smell the food, we taste the food, we touch the food. This state of experiencing food has been called many names, including “mindful eating”. By being present and focused on our senses (and not on our thoughts), we help our body enjoy the food and absorb the maximum amount of nutrients it contains.

When we are not consciously present during our meals, be it because at the same time we work on the computer or watch TV or scroll through our mobile or drive or walk or think about some pressing issue that is of great concern to us, this automatically means that we will miss the cephalic phase of digestion. The brain will not focus on food, it will focus on something else. In turn, this means that the corresponding gastric fluids and enzymes will not be excreted, which in turn means that a corresponding percentage of nutrients will not be absorbed. Even if we have just had the most nutrient-rich food on the planet, our body will have the experience of a very poor meal.

What’s more, after a while the brain will catch up with the lack of nutrient absorption. “Wait a minute, where are my nutrients, my carbs, my fats, my proteins, my trace elements, my vitamins?” To correct this situation, the brain will make us feel hungry again, so that we may eat and get the nutrients that we missed. And this, regardless of the calories (energy load) we have already absorbed!

If you sometimes find that you get hungry again very quickly, step back and think: How did you eat your last meal? Quickly, distracted, multitasking, detached from your physical senses, with your mind full of thoughts that have nothing to do with your meal? You may think that this way you’re being productive and efficient, but your body thinks otherwise. And the body’s survival mechanisms always win over willpower.

Here’s a tip: next time you eat, do just that; focus on eating and enjoy food with all your senses. Sit down at the table. Breath. Take a moment to observe the food. Smell the food. Explore the flavors in your mouth. Experiment. Try feeling your senses instead of thinking.

Here are some handy instructions:

  • Turn off the TV
  • Turn off the computer.
  • Put your phone in silent mode and leave it aside.
  • Give yourself a few seconds to take in the looks and the aroma of the food.
  • Breathe and slow down.
  • Eat slowly. Chew slowly. Put the fork down after every bite.
  • Enjoy the flavors.
  • Observe and feel: is it sweet, sour, bitter, salty, does it have a delicious taste?
  • Put all your senses into the game. The food has a look, smell, taste, texture, touch, sound! (yes, there are sounds when we eat; observe them too!)

Do you feel the difference?

Book a free intruductory session with us!

Στράτος Λάσπας
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About Στράτος Λάσπας

Stratos has been certified as a Mind-Body Nutrition & Eating Psychology Coach by the Institute for the Psychology of Eating (IPE), approved and supervised by the Colorado Department of Higher Education (USA). In IPE’s internationally acclaimed program, he learned powerful cutting-edge tools and protocols that enable him to work with weight issues, body image challenges, overeating, binge eating, and a variety of nutrition-related health concerns such as digestion, fatigue, mood, immunity, and others.

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