Are Humans Herbivores, Omnivores, or Carnivores?

The question of whether humans are herbivores, omnivores, or carnivores often sparks debate. We've heard it from healthcare professionals and some kind of experts: "Animal products are essential for a healthy diet." Is this true?

On one side, some believe our evolution points to a meat-heavy diet; including paleo followers, carnivore advocates, and many who adhere to the standard American diet. On the other side, vegans argue that humans are naturally meant to thrive on a plant-based diet.

So, what do our bodies really tell us?

The truth is, our digestive systems and nutritional needs are complex, reflecting a mix of both plant and animal-based food sources. The key is balance, and what truly matters is finding a lifestyle that supports our health, energy, and values. The debate isn't about right or wrong, but about what works best for each individual and the planet.

A Lesson in Anatomy

In nature, animals typically fall into one of three categories: carnivores (meat-eaters), herbivores (plant-eaters), and omnivores (eating both). While it's true that humans are behavioral omnivores (meaning we can eat a variety of foods, including animal products), our anatomy suggests we’re better suited for a plant-based diet.

Here's why:

Mouth & Teeth

• Carnivores: Have wide mouths and sharp, pointed teeth for tearing flesh. Their jaw movement is limited, focusing mainly on up-and-down motion for biting into meat.

• Herbivores: Have smaller mouths, flat teeth, and more versatile jaws for grinding and chewing fibrous plants.

• Humans: Our mouths are smaller, and our teeth are flat and blunt, ideal for grinding plant material. Our canines are not sharp enough to tear meat, suggesting plant-based eating is more natural for us.

Digestive System:

• Carnivores: Most carnivores lack salivary amylase (the enzyme that breaks down starch) and can swallow large chunks of meat.

• Herbivores: Produce more digestive enzymes and their digestive tracts are longer to allow slow digestion of fibrous foods.

• Humans: We produce significant amounts of salivary amylase to break down starches. Our small intestines are long, further supporting a plant-based diet.

Stomach & Acidity:

• Carnivores: Have larger stomachs and higher stomach acidity to kill pathogens in decaying meat.

• Herbivores: Have smaller stomachs and longer intestines for digesting plants.

• Humans: Our stomachs are more acidic when empty but become less so after eating, likely to help prevent pathogens rather than aid digestion. This is similar to some herbivores, like beavers and rabbits.

Humans have the ability to eat both plants and animals. This adaptability was vital for survival, especially in harsher climates where plant-based foods were scarce. Animal products, being calorie-dense, provided the energy needed to survive difficult conditions. However, those survival pressures no longer apply. Today, meat consumption is driven more by cultural norms, personal preferences, and food marketing than by survival needs.

The Modern Reality

Over 40% of the global population is overweight or obese, with projections estimating this will rise to 50% by 2035. Meanwhile, chronic diseases are now responsible for the majority of deaths worldwide, putting immense strain on healthcare systems.

At the same time, animal-based diets are a leading contributor to environmental damage, including deforestation, loss of biodiversity, and climate change. The resources required to sustain animal farming, land, water, and energy are immense, and the environmental toll is significant.

While humans have the anatomical ability to consume animal products, once essential for survival, it is not necessarily the key to optimal health or longevity.

Unlike our ancestors, who had to hunt for survival, we now live in a world of food abundance. Our bodies are much better adapted to a plant-based diet, and modern research shows that plants can lower the risk of chronic diseases, promote longevity, and support overall health, all while helping maintain a healthy waistline.

It's time to make conscious choices that benefit both our well-being and the future of the planet.

Sources:

• The Evolution of Stomach Acidity and Its Relevance to the Human Microbiome

• Hidden diversity: comparative functional morphology of humans and other species

• Carnivore

• The Expensive-Tissue Hypothesis in Vertebrates: Gut Microbiota Effect, a Review