What is an omnivorous person? Decoding the human diet

January 14, 2026 •

4 min read

A 2024 review found that balanced omnivorous diets, encompassing both plant and animal foods, provide a sustainable way for humans to acquire essential nutrients. An omnivorous person is one who consumes both plant-based and animal-based foods, a dietary pattern that has been integral to human evolution for millennia. This flexibility has allowed humans to thrive in a vast array of environments worldwide by adapting their food sources.

Quick Summary

This article explores the definition of an omnivorous person, detailing the biological characteristics and historical context that shaped human dietary habits. It explains what constitutes an omnivore's diet, contrasts it with vegetarian and carnivorous approaches, and outlines the nutritional considerations for a balanced, mixed-food intake.

Key Points

Definition: An omnivorous person eats both plant-based and animal-based foods, a diet common to humans and many other animal species.
Biological Adaptations: Human biology, including dental structure and digestive tract length, is adapted to process both meat and plant matter effectively.
Nutritional Flexibility: The ability to consume a variety of food sources provides omnivores with a wide range of nutrients and adaptability to different environments.
Health Balance: A healthy omnivorous diet requires conscious choices to balance plant and animal foods, avoiding excessive intake of saturated fats and processed items.
Evolutionary History: Humans evolved as omnivores, with archaeological evidence showing a mixed hunter-gatherer diet for millions of years.
Dietary Comparison: Unlike vegetarians (plants only) and carnivores (meat only), omnivores have a mixed diet, offering more flexibility but also requiring attention to balance nutrients like B12 and fiber.

Understanding the Biological Omnivore

An omnivorous person is, by biological definition, a being capable of digesting and obtaining energy from both plant and animal matter. The word itself originates from the Latin 'omni' (all) and 'vorare' (to devour), signifying an "all-eater". This capability is not just a modern human preference but is deeply rooted in our evolutionary history, with archaeological evidence suggesting our ancestors were hunter-gatherers who consumed a mixed diet.

Anatomical and Physiological Indicators

Several physical traits in humans point towards our omnivorous nature:

Teeth: Our dental structure is a key indicator. Humans possess a mix of sharp incisors for cutting meat and broad, flat molars for grinding plants, unlike the highly specialized teeth of pure carnivores or herbivores.
Digestive System: The length and acidity of our digestive tract are also intermediate between carnivores and herbivores. Our intestinal tract is shorter than that of herbivores, which have very long tracts to digest fibrous plant matter, but longer than that of obligate carnivores.
Digestive Enzymes: Saliva contains amylase, an enzyme that starts the chemical breakdown of starches in the mouth, aiding in the digestion of plants. Our stomach acid is also stronger than herbivores', helping to break down meat and protect against pathogens found in animal products.

The Omnivore's Dietary Profile

For a person following an omnivorous diet, the range of acceptable foods is vast and diverse. This dietary pattern includes food from all major food groups and offers the flexibility to adapt to seasonal availability and environmental resources. A balanced omnivorous diet typically draws from the following categories:

Animal Products: This includes lean meats (poultry, beef, pork), fish and seafood (salmon, cod), eggs, and dairy products (milk, cheese).
Plant-Based Foods: A healthy omnivore's diet relies heavily on a wide variety of plant foods, including fruits, vegetables, whole grains, legumes, nuts, and seeds.
Other Sources: Omnivores also consume fungi like mushrooms and sometimes algae (seaweed).

Omnivore vs. Other Dietary Choices

Understanding what is an omnivorous person is best done by comparing this diet with its counterparts: the vegetarian and carnivorous diets. While biological predisposition points to omnivory, modern humans can make conscious dietary choices for ethical, environmental, or health reasons.

Comparison Table: Omnivore vs. Vegetarian vs. Carnivore


Feature	Omnivore	Vegetarian	Carnivore
Primary Food Sources	Both plants and animals	Exclusively plants, with some exceptions (e.g., eggs, dairy)	Exclusively meat from animals
Nutritional Flexibility	High; able to obtain nutrients from a wide range of sources	Moderate; requires careful planning to ensure complete protein and B12 intake	Limited; relies on animal products for all nutrients
Biological Adaptations	Combination of teeth types (incisors, molars) and intermediate digestive system	Human anatomy is naturally omnivorous, but can adapt	Highy specialized teeth (large canines) and short, simple digestive system
Potential Health Considerations	Risk of high saturated fat intake if not balanced	Risk of nutrient deficiencies (e.g., B12) if not supplemented	Historically, less diverse nutrient intake and potentially high fat

Nutritional Considerations for Omnivores

While an omnivorous diet offers the broadest nutritional palette, it is not inherently healthy without balance and moderation. The key to a healthy omnivorous lifestyle is to focus on nutrient-dense, whole foods while limiting processed options.

Tips for a Balanced Omnivorous Diet

Prioritize Plants: Make fruits, vegetables, and whole grains the foundation of your meals.
Choose Lean Proteins: Opt for lean meats, fish, and plant-based protein sources like legumes and nuts.
Monitor Fats: Be mindful of saturated and trans fats found in some animal products, and favor healthy fats from sources like olive oil and nuts.
Ensure Nutrient Variety: A diverse diet naturally provides essential vitamins and minerals, including vitamin B12 from animal products and Vitamin C from plants.

The Flexibility and Resilience of Omnivores

The main advantage of being an omnivore is the dietary flexibility it provides. In times when a particular food source becomes scarce, an omnivorous person can easily shift to a more plentiful option, a trait that was vital for survival throughout human history. This adaptability also gives individuals the freedom to choose their dietary balance based on personal preference, health goals, or ethical considerations, without facing the more complex nutritional challenges associated with highly restrictive diets.

Conclusion

To put it simply, an omnivorous person is someone who eats both animal and plant-based foods, a dietary pattern supported by our biological makeup and evolutionary history. The flexibility and wide range of food sources available to omnivores offer a clear nutritional advantage, making it easier to acquire all essential nutrients. However, a truly healthy omnivorous diet depends on making balanced and conscious food choices. By prioritizing whole foods and understanding nutritional needs, an omnivorous person can build a diet that is both varied and beneficial for their overall health.

Optional Authoritative Outbound Link

For further reading on how the human diet has evolved, you can explore detailed archaeological findings and studies on the website of reputable scientific and educational institutions, such as the Frontiers for Young Minds publication on human diet evolution, found here: Human Diet Evolution: Meat, Fire, and Tapeworms.

Frequently Asked Questions

Yes, humans are naturally omnivores. Our biological makeup, including our teeth and digestive system, is adapted to consume and process both plants and animals. While modern humans can choose alternative diets, our physiology points to an omnivorous past.

The main difference is their primary food source. An omnivore eats both plants and animals, while a carnivore eats only meat. This is reflected in their different dental structures and digestive systems.

A person can choose to follow a vegetarian diet, which means they are behaving as a vegetarian. However, their biological ability to digest meat remains, so physiologically they are still an omnivore, even if they don't eat animal products.

All three diets can be healthy if they are well-planned and balanced. An omnivorous diet can make it easier to get certain nutrients like Vitamin B12, but it also carries risks if not managed properly, such as high saturated fat intake. The healthiest diet depends on individual choices and proper nutritional planning.

The word omnivore comes from Latin meaning 'all-eater,' but this doesn't mean an omnivorous person eats literally everything. An omnivore consumes a wide variety of plant and animal matter, but their specific diet is shaped by cultural, personal, and health factors.

Examples of food include a vast range of options. A single meal might contain chicken (animal), rice (plant), and vegetables (plant). Other examples include eggs, fish, dairy, nuts, fruits, and grains.

Omnivores benefit from both plant and animal sources. Animal products are rich in complete proteins, B vitamins (like B12), and minerals such as iron and zinc. Plant-based foods provide fiber, vitamins, and minerals that can reduce the risk of certain diseases.