What If Eating Only Animal Foods Causes No Deficiencies?

What if eating only animal foods causes no deficiencies?

by Laurent Glatz – for Athletic Carnivore

You’ve been told this your whole life.

Cut out plants and you’ll become deficient.

In vitamins. In fiber. In antioxidants. In everything supposedly essential to protect your health.

This is one of the most deeply ingrained nutritional dogmas of our time.

Yet, when we examine human physiology and the actual composition of animal foods, this catastrophic scenario begins to seriously waver.

Because the question deserves to be asked clearly.

If someone eats exclusively animal-based foods—meat, fish, eggs, offal, seafood—what deficiencies actually appear?

The answer, when analyzing nutritional data, is far less dramatic than commonly imagined.

Animal Foods Are Nutritional Powerhouses

In reality, animal foods rank among the most nutrient-dense sources available in the human diet.

Red meat, for example, provides complete proteins containing all essential amino acids, but also heme iron, which is highly bioavailable, zinc, selenium, phosphorus, and a large portion of B vitamins.

Vitamin B12, indispensable for nervous system function and red blood cell production, is found almost exclusively in animal products.

Eggs supply choline, essential for brain function and liver metabolism. The yolk also contains vitamin A, vitamin D, vitamin K2, and numerous micronutrients.

Fatty fish provide long-chain omega-3 fatty acids, EPA and DHA, crucial for brain and cardiovascular health.

Offal, often overlooked today, represents true nutritional concentrates. Liver contains remarkable amounts of vitamin A, copper, folates, and many B vitamins.

In other words, regarding essential micronutrients, animal foods cover a large portion of human needs.

But critics always return to the same questions.

Vitamin C. Fiber. And certain minerals.

The Question of Vitamin C

In a carbohydrate-rich diet, vitamin C needs are relatively high because this vitamin shares some cellular transporters with glucose. When blood sugar is elevated, competition between glucose and vitamin C increases.

In a very low-carb context—such as a carnivore diet—this competition decreases. Physiological vitamin C requirements therefore appear lower.

Moreover, fresh meat contains small amounts of vitamin C, particularly in certain tissues and organs. Traditional populations consuming diets very rich in animal products, like some Arctic cultures, historically did not develop scurvy when consuming fresh meats and organs.

Fiber Is Not Always the Central Issue

Fiber also raises many concerns.

Dietary fiber plays several roles in carbohydrate-rich diets, notably slowing glucose absorption and nourishing certain gut bacteria.

But in a diet very low in carbohydrates and starch, digestive physiology changes. Fermentation gas production decreases, stool volume is lower, and bowel transit can function normally without high fiber intake.

Studies on ketogenic diets show that many people with digestive issues see symptom improvement when fermentable fibers decrease.

Minerals and Overall Balance

The question of minerals remains.

Meat, seafood, and offal are rich in zinc, iron, selenium, and phosphorus. Sodium and potassium are also present, especially when the diet includes various types of meats and fish.

Some minerals like calcium may be lower if the diet completely excludes dairy or small fish eaten with bones. But even then, bone metabolism also strongly depends on vitamin D, vitamin K2, and overall hormonal balance.

In practice, available data on carnivore diets reported in literature and observational cohorts rarely show major nutritional deficiencies when the diet includes a variety of animal foods.

The Key: Eat the Whole Animal, Not Just Muscle Meat

The key is not just eating meat.

It’s eating the animal.

Muscle meats, fish, eggs, seafood, and ideally some offal. This diversity covers a broad range of micronutrients.

Of course, science on strict carnivore diets remains limited. Controlled clinical trials are rare, and most data come from observations and individual experiences.

But one thing is becoming increasingly clear.

The idea that human nutrition cannot function without plants is less obvious than previously asserted.

For most of human evolution, animal foods made up a major part of energy and nutrient intake.

Which ultimately leads to a simple question.

If the most nutrient-dense foods in our diet are animal-based… are we really sure that the modern nutritional problem stems from a lack of plants?

#AthleticCarnivore #Carnivore #LowCarb #MetabolicHealth