Why an Animal-Based Diet is the Most Bioavailable and Optimal Way to Nourish the Human Body
When I first learned the term bioavailability, it changed how I saw food. It means how much of what you eat, your body can actually absorb and use. You can eat plenty of nutrients on paper, but if your body can’t access them, they serve no purpose. This concept is at the heart of why I believe an animal-based diet is the most natural and efficient way for humans to thrive.
Animal foods deliver nutrients in the exact form your body needs. You don’t need to convert, extract, or compensate. Your body recognizes them, absorbs them, and uses them. For example, iron from steak comes as heme iron, which your body absorbs easily. The iron in plants comes as non-heme iron, and much of it passes through unused because it’s blocked by compounds like phytates. The same happens with zinc, calcium, and magnesium. Plants contain antinutrients that bind to minerals and prevent absorption. You could eat large portions of spinach or lentils and still not meet your nutrient needs.
Protein tells a similar story. Animal proteins are complete, meaning they contain all the essential amino acids your body requires to build and repair tissue. Eggs, fish, and meat are nearly perfect in their amino acid profile. Plant proteins, even in large amounts, often fall short. They are missing one or more amino acids and contain fiber and inhibitors that make digestion less efficient. This is one reason many people on plant-based diets struggle with fatigue, slow recovery, and hair loss over time.
Fat-soluble vitamins are another example. Vitamins A, D, E, and K2 are only found in meaningful amounts in animal foods. These nutrients are essential for hormone balance, immune function, and brain health. Vitamin A from liver, for instance, is already in its active form, called retinol. Your body uses it immediately. The beta-carotene in plants must be converted to retinol, and that process depends on genetics, thyroid function, and overall health. Some people convert well, others barely at all. The same goes for omega-3 fats. Fish and eggs provide EPA and DHA, the exact forms your brain and heart rely on. Plants only provide ALA, which your body must convert, and less than five percent makes it through that conversion.
B vitamins tell an even clearer story. Vitamin B12, which supports nerve function and energy metabolism, exists only in animal foods. Deficiency leads to neurological problems and fatigue, yet millions of people eating plant-based diets develop it unknowingly. Even the B vitamins found in plants are often less bioavailable than their animal counterparts.
Some people argue that plants provide all we need if we eat a wide enough variety. But eating is not about checking boxes; it’s about feeding the human body the nutrients it evolved to process. For hundreds of thousands of years, humans survived and thrived as hunters who occasionally foraged, not the other way around. Our teeth, stomach acid, and digestive enzymes are built for digesting meat and fat efficiently. Animal foods sustained brain growth, fertility, and strong immune systems long before agriculture existed. When we moved toward grains and plant-based staples, archaeological evidence shows declines in bone density, stature, and overall health.
I’m not suggesting that plants are bad. Some people tolerate them well and enjoy them in moderation. But from a biological perspective, animal foods are what built the human body and continue to sustain it best. They supply everything we need in forms our body can use immediately, without the friction or conversion losses that come with plants.
When I began eating this way, my own health transformed. Inflammation disappeared, my energy stabilized, and I no longer felt the mental fog that used to follow me through the day. I learned that it wasn’t about restriction, but nourishment. Food stopped being complicated. A few simple, nutrient-dense meals gave me everything my body needed.
Bioavailability isn’t a trendy word; it’s a reminder of what we’re made for. The closer we eat to our biological design, the better our body performs. Animal foods like meat, eggs, fish, and healthy fats remain the most bioavailable, nutrient-dense sources on earth. For most people, they’re not only enough, they’re optimal. When we return to that simplicity, health becomes natural again.
For readers who want to understand the science and history behind why animal foods are essential for human health, I recommend “The Big Fat Surprise” by Nina Teicholz. This book exposes how flawed nutrition science and industry influence led to decades of fear around saturated fat and meat. Teicholz presents clear, evidence-based research showing that traditional animal foods are not the problem but the foundation of a healthy, bioavailable diet.
Disclaimer: The content shared here is for informational and educational purposes only and should never be taken as medical advice.
In writing this blog post, my goal is to distill research findings into a clear, approachable format that encourages critical thinking and empowers you to make informed decisions about your health.
