What is the main purpose of meat?

January 3, 2026 •

2 min read

For over three million years, human ancestors have consumed meat, fundamentally shaping our evolution and biological development. This deep history with animal-based foods helps explain what is the main purpose of meat, which is primarily to provide a dense, highly bioavailable source of key nutrients crucial for growth, brain development, and metabolic function.

Quick Summary

Meat's primary purpose is to provide a nutrient-dense source of complete protein, highly bioavailable iron, vitamin B12, and other vital micronutrients essential for human health and development.

Key Points

Complete Protein: Meat provides a high-quality, complete protein containing all essential amino acids for growth and tissue repair.
Bioavailable Iron: It is the best source of heme iron, which is significantly more absorbable by the body than plant-based iron.
Essential Vitamins: Meat supplies vital vitamins, including vitamin B12, which is almost exclusively found in animal products.
Brain Development: The nutrient density of meat was crucial for the brain growth of our early human ancestors.
Nutrient Synergy: Meat contains a unique matrix of nutrients and bioactive compounds that enhance the absorption of minerals from other foods.
Modern Choice: In modern times, the decision to include meat is a balance between its nutritional benefits and personal ethical or environmental considerations.

The Core Nutritional Functions of Meat

From an evolutionary perspective, consuming meat offered early humans a concentrated source of energy and nutrients difficult to obtain from plants alone, driving the development of larger brains. Modern science confirms meat provides essential physiological compounds.

High-Quality Complete Protein

Meat is a key source of high-quality, complete protein, containing all nine essential amino acids necessary for human requirements. This supports tissue repair, growth, and muscle maintenance. Its amino acid profile is particularly effective for muscle synthesis.

Bioavailable Micronutrients

Meat is rich in micronutrients with high bioavailability.

Heme Iron: Found only in meat, heme iron is more easily absorbed than plant-based non-heme iron, aiding in anemia prevention.
Vitamin B12: Meat is a primary natural source of B12, crucial for nervous system health and red blood cell formation.
Zinc and Selenium: Meat provides easily absorbed zinc and selenium, important for immune function and overall health.

Essential Fatty Acids and Bioactive Compounds

Meat also offers beneficial fats for brain function and vitamin absorption. Bioactive compounds like creatine and carnosine support muscle health and cognitive function.

Comparison: Animal-Based Nutrients vs. Plant-Based Nutrients

A plant-based diet can be nutritionally complete but may require careful planning and supplementation to match meat's bioavailability and nutrient density.


Feature	Animal-Based (Meat)	Plant-Based
Protein	Complete protein with all essential amino acids.	Most are incomplete; requires careful combining to get full profile.
Heme Iron	Exclusive source; high bioavailability (~15-35% absorbed).	Non-heme iron only; low bioavailability (~2-10% absorbed).
Vitamin B12	Natural and primary source.	Must be fortified or supplemented.
Omega-3s (EPA/DHA)	Primary source of long-chain omega-3s.	Plant-based versions have low conversion rates in humans.
Zinc Bioavailability	Readily absorbed due to fewer inhibitors.	Absorption often reduced by anti-nutrients like phytates.

The Role of Meat in Human Evolution

The dietary shift to meat offered a significant evolutionary advantage, providing more calories and nutrients with less digestive effort. This metabolic efficiency supported the development of larger brains. Tool use for hunting and butchering also spurred social and cognitive advancements. Meat consumption was a crucial factor in the expansion of our brain size.

Ethical and Modern Dietary Considerations

Contemporary diets consider meat's environmental and ethical implications. While nutritious, alternatives exist, and consumers weigh benefits against impact. Vulnerable groups may especially benefit from meat's nutrients like iron and B12. Balanced dietary planning can ensure nutrient needs are met regardless of meat consumption. Resources for plant-based diets can be found at the Vegan Society's website (https://www.vegansociety.com/go-vegan/why-go-vegan).

Conclusion

Historically, the main purpose of meat was to provide concentrated protein, iron, B12, and other essential nutrients for health and growth, significantly contributing to human evolution and brain development. Today, while alternatives exist, meat remains a valuable source of highly bioavailable nutrients for many diets. Understanding this role is key to making informed dietary choices.

Frequently Asked Questions

Meat is considered a high-quality or 'complete' protein source because it provides all nine essential amino acids that the human body cannot produce on its own. The amino acid profile is highly suitable for building and repairing human tissues.

Yes, the iron from meat (heme iron) is significantly more bioavailable and easily absorbed by the body compared to the iron found in plants (non-heme iron). Meat also contains a 'meat factor' that enhances the absorption of non-heme iron from plant foods when eaten together.

Vitamin B12 is essential for nerve function and producing red blood cells. Meat and other animal products are the primary natural dietary source of this vitamin, making meat an important food for preventing B12 deficiency.

Anthropologists believe the consumption of energy-dense meat was crucial for the evolution of larger brains in early humans. The high-quality calories and nutrients allowed for the expansion of brain size and a smaller, more efficient digestive tract.

No, you do not need meat to get enough protein, but careful dietary planning is required on a plant-based diet. While meat is a convenient source of complete protein, combining various plant protein sources, like beans and grains, can also meet amino acid needs.

Yes, but it requires strategic dietary planning and, often, supplementation. While plants provide many nutrients, replacing meat's high bioavailability of iron, B12, and long-chain omega-3s often requires special attention to fortification or supplements.

Beyond protein and minerals, meat is a source of bioactive compounds like creatine and carnosine, which support muscle health and have potential anti-inflammatory properties. It can also increase satiety, which helps with appetite regulation.