The Optimal Diet Considers the Bioavailability of Food

In this article I will discuss the second factor for achieving an optimal diet: 

The optimal diet considers the bioavailability of food.

The Optimal Diet

  1. The optimal diet is dense in nutrients.
  2. The optimal diet considers the bioavailability of food.
  3. The optimal diet uses the most efficient fuel source.
  4. The optimal diet utilizes intermittent fasting.

What is bioavailability?

Bioavailability is the degree to which your body can ABSORB the nutrients in the food you eat.

Let’s take a look at the process of absorption. How does your body go about absorbing food?

The Process of Absorption

DIGESTION is the process of breaking food down into smaller and smaller pieces so the body can absorb it.  This is accomplished in 2 ways: mechanically and chemically.

Mechanical digestion occurs when we chew our food. Our bodies continue the process chemically through the acids and enzymes that come from our saliva, stomach and small intestines. Once our food is broken down so the nutrients can be extracted, they are transported through the bloodstream to our cells where they are absorbed.

You might think that our body absorbs 100% of the nutrition from the food we eat.

But there are a variety of factors, both positive and negative, that affect the bioavailability or the absorption rate of food in our bodies.

Negative Influencers of Bioavailability

ANTI-NUTRIENTS negatively affect bioavailability. Anti-nutrients are chemical compounds in plants that impede our body’s rate of absorption.

Anti-nutrients include:

1. Phytic Acid

Phytic acid prevents zinc, iron, calcium and other minerals from absorbing into the body. Found in seeds, nuts, grains and legumes.

2. Gluten

Gluten is an enzyme inhibitor that causes gastrointestinal distress. Not only can gluten cause digestive problems, but it can contribute to leaky gut syndrome or autoimmune disease, allergic reactions, and cognitive problems. Found in wheat, rye and barley.

3. Tannins

Tannins are a type of enzyme inhibitor that prevent adequate digestion and can cause protein deficiency and gastrointestinal problems. Because we need enzymes to properly metabolize food and usher nutrients to our cells, molecules that inhibit enzymes can cause bloating, diarrhea, constipation and other GI issues.

4. Lectins

Lectins break down the lining of the digestive tract creating a leaky gut. Found in beans, wheat, brown rice, white potato and night shades.

5. Oxalates

Oxalates bind with calcium to create kidney stones, inflammation and arthritis. Found in sesame seeds, soybeans, and black and brown varieties of millet.

6. Saponins

Similar to lectins, saponins affect the gastrointestinal lining, contributing to leaky gut syndrome and autoimmune disorders. They’re particularly resistant to digestion by humans and have the ability to enter the bloodstream and trigger immune responses. Found in nightshades, legumes, amaranth, and buckwheat.

Why do plants have these chemical compounds?

They are a defense mechanism.  Plants can’t run away when a predator decides to eat them.  So plants have developed chemical compounds to discourage insects and animals from eating them.

Is it possible that these compounds are a result of the curse God placed on the ground due to sin?

And to Adam he said, “Because you have listened to the voice of your wife and have eaten of the tree of which I commanded you, ‘You shall not eat of it,’ cursed is the ground because of you; IN PAIN YOU SHALL EAT OF IT all the days of your life;

Genesis 3:17

Could it be one of the reasons God introduced meat into the food chain after the flood (Genesis 9:1-3)?

Positive Influencers of Bioavailability

Animals positively affect the bioavailability of food. There are certain aspects of a plant’s nutrient profile that aren’t compatible with a human’s, so God uses animals to bridge the gap.

Animals help make plants better for us in 3 ways:

  1. Fiber
  2. Convertibility
  3. Deficiencies


The human body is not designed to absorb fiber, therefore it is inefficient in extracting nutrients from plant materials.  However, animals with a rumen (cow, sheep, goat, deer, bison etc.), or a divided stomach are very proficient in extracting nutrients from plant materials. Therefore when we eat meat we benefit from the nutrition provided to the animal by the plant.


Animals convert the nutrient profiles in plants to match the nutrient profiles needed by humans.

For instance, plants produce beta-carotene, a form of vitamin A.  When animals eat grass, they convert beta-carotene into retinol, the form of Vitamin A humans need.

Similarly, the human body needs DHA, a form of Omega-3 fatty acid.  Plants produce ALA, an Omega-3 fatty acid.  When ruminant animals eat grass they convert ALA to DHA.


The body can’t absorb what the food cannot offer. Plants don’t have all of the nutrients the body needs.

Nutrients not found in plants are: vitamin B12, the omega-3 fatty acid DHA, heme Iron, vitamin D3, creatine, choline and vitamin A (retinol).

Plants are considered incomplete proteins because they don’t contain the 9 essential amino acids our bodies need.  While there are exceptions (soy and chia seeds), the amounts these plants contain are too small for optimal health.


As we go about the process of choosing an optimal diet, we have to consider bioavailability. Foods are bioavailable when we can efficiently absorb them into our system.

Due to anti-nutrients, fiber, convertibility and deficiencies, plants are less bioavailable that animal sources.  While we can still consider plants as part of our diet going forward we have to acknowledge that animal products play a significant role in achieving optimal health.

In my next article, The Optimal Diet Uses the Most Efficient Fuel Source, we’ll discuss which diet is best for you:

  • Keto
  • Carnivore
  • Paleo
  • Atkins
  • Vegetarian
  • Vegan