An omnivore diet is a dietary pattern that includes a wide variety of foods from both plant and animal origins. The term itself provides a direct description, derived from the Latin words omnis, meaning “all,” and vorare, meaning “to devour.” This approach to eating is not defined by a rigid set of rules but by the inclusion of all food groups. This classification is based on the biological capacity to derive energy from a mixed diet of plant and animal matter.
Foundational Food Groups
An omnivorous diet is characterized by its inclusion of a broad spectrum of food sources, separated into plant-based and animal-based categories. This includes fruits, vegetables like those from the Brassica family (such as broccoli and cabbage), whole grains, and legumes. Nuts and seeds also represent a significant component of the plant-derived foods available within this dietary framework.
The diet is also defined by the consumption of animal-based foods. This category includes meat, such as red meat and poultry, as well as fish and other seafood. Dairy products, including milk and cheese, and eggs are also staple components sourced from animals.
The Human Omnivore
Whether humans are naturally suited for an omnivorous diet is often addressed by examining anatomical and physiological features. Human dentition provides some of the clearest evidence, as our teeth are not specialized for one type of food. We possess sharp incisors and canines for biting and tearing, similar to carnivores, alongside flatter molars designed for grinding and chewing, a feature of herbivores.
Further evidence is in the human digestive system, which shows characteristics intermediate between those of pure carnivores and herbivores. For example, the length of the human small intestine is longer than that of a typical carnivore but shorter than that of an herbivore. Unlike many herbivores, humans lack specialized digestive sacs like fermenting vats, which are necessary to break down tough plant cellulose efficiently. Anthropological studies of early human ancestors also indicate a history of consuming both plants and animals, suggesting omnivory was a survival strategy.
Nutritional Completeness
A varied omnivore diet can provide a full spectrum of necessary macronutrients and micronutrients by drawing from both plant and animal kingdoms. Animal-based foods are particularly reliable sources for certain nutrients that can be more difficult to obtain from plants alone. These include complete proteins, which contain all nine essential amino acids, and vitamin B12, which is almost exclusively found in animal products. Animal sources also provide heme iron, a form of iron that is more readily absorbed by the body than the non-heme iron found in plants.
Simultaneously, plant-based foods contribute their own unique and beneficial nutritional components. Plants are the primary source of dietary fiber, which is important for digestive health. They also supply an abundance of vitamin C, folate, magnesium, and various phytochemicals—bioactive compounds that are not found in animal foods. The combination of these food groups allows the nutritional strengths of one group to compensate for the limitations of the other.
Variations in Omnivore Health
The term “omnivore diet” is a broad classification, and its impact on health is determined by the specific food choices made within it. An unhealthy omnivorous pattern is characterized by a high intake of processed meats, refined grains, added sugars, and saturated fats, with insufficient consumption of fruits and vegetables.
In contrast, a health-promoting omnivore diet emphasizes whole foods. The Mediterranean diet is a well-studied example of such a pattern, featuring a high intake of fruits, vegetables, whole grains, legumes, nuts, and fish, with moderate amounts of dairy and poultry and very little red meat. This style of eating is associated with positive health outcomes, primarily because it is rich in fiber and unsaturated fats while being low in sodium and refined carbohydrates. Ultimately, the healthfulness of an omnivore diet depends on prioritizing nutrient-dense foods over highly processed options.