The question of what diet humans are meant to consume has been surrounded by lively debate for years. The bottom line is that there have been many populations of humans that have thrived by eating a fully plant-based diet free of any animal flesh or products, and millions of modern humans eat the same way. The same cannot be said of diets composed completely of meat and animal products without any vegetables, carbs, or other plant-based foods. Following such a diet can lead to a seriously uncomfortable life due to nutrient deficiencies. Further evidence of the human propensity for a mainly herbivorous diet can be found in a range of human traits including the digestive system.

What’s the difference between herbivores, carnivores and omnivores?

When it comes to eating habits, there are three major categories, each with their own subcategories. Virtually every animal on earth, including humans, can be sorted into groups based on their dietary preferences. The three major categories are omnivores, herbivores, and carnivores.

Omnivores

Omnivores are those animals that eat both plants and other animals. The group of animals considered omnivores is highly diverse and includes everything from birds to bears, dogs, and insects. Most humans would also fall into this category, as they consume both plants and other animals. Omnivores can be hunted as prey or be the hunters themselves depending on their place in the food chain. Some omnivores, such as rats and bears, are scavengers and will eat dead animals that they happen across, alongside foods originating from plants and the carcasses of animals they hunt themselves.

Herbivores

Animals that can be classed as herbivores include cattle, deer, and elephants. These amazing animals are specially adapted to be able to break down the tough, fibrous plants that make up most of their diet. One subcategory of herbivores is ruminants, including sheep and giraffes. These animals have four separate stomach chambers that all work together to maximize the amount of nutrients they can extract from the plants they eat.

Carnivores

Carnivores are those animals that eat other animals as a primary source of nutrition. It’s a common misconception that carnivores exclusively eat meat. This is the case for obligate carnivores such as cats that depend on meat for all of their nutrients. Most carnivores, however, eat some combination of meat and other foods, and thus could be regarded as omnivores. Hypercarnivores get 70% of their food from the flesh of other animals; mesocarnivores consume other animals for 50% of their diet; hypocarnivores depend on meat for 30% of their food. Another misconception is that carnivores consume herbivores for their meals. This is not true for all carnivores. Tertiary carnivores eat other carnivores. One example of a tertiary carnivore is killer whales, or orcas, which hunt seals and sea lions that in turn hunt fish, squid, and octopuses.

Are humans carnivores, omnivores, or herbivores?

The question of which dietary category humans fall into is one that has sparked much debate. What we know for sure is that there are people who thrive on plant-based diets and who avoid consuming not just meat but all animal-derived products. There are also a great number of people who consume omnivorous diets consisting of both animal- and plant-derived foods. The small population of purely carnivorous humans is made up primarily of those seeking to lose a large amount of weight quickly. Following a purely carnivorous diet void of any plant-derived ingredients and foods can lead to constipation due to a lack of fiber, bad cholesterol, and increased risk of heart disease.

Are humans omnivores?

There is a strong case to be made for humans being categorized as omnivorous. After all, millions of people around the world follow a diet made up of both plants and other animals and animal products and live a relatively healthy life. Yet while we may eat animals and their byproducts as part of our diet, we do not require meat or animal products to live happy and healthy lives as long as we are eating a varied and well-planned plant-based diet and using supplements if required. In fact, there is ample evidence suggesting that forgoing animal flesh and products can improve our health and well-being.

Are humans herbivores?

As demonstrated by the 79 million vegans around the world, following a diet that is fully plant-based and free of animal flesh and products is perfectly compatible with human health and thriving. Following a plant-based diet has also been tied to a number of positive health outcomes in humans. For example, eating plant-based has been tied to a decreased risk of developing severe COVID-19, and to improved cardiovascular health.

Our anatomy further suggests that our best diet would resemble that of herbivores rather than carnivores. For example, even our saliva contains the digestive enzymes characteristic of herbivores and absent in the saliva of carnivores.

Are humans carnivores?

Humans are not able to survive on a purely carnivorous diet. Attempting to do so will likely lead to constipation due to a lack of fiber and possibly even scurvy, as cooked meat does not contain vitamin C. Diets high in meat, especially red meat and processed meats, have also been connected to increased risk of developing heart disease and high cholesterol.

Why are humans not carnivores?

Both our nutritional needs and our physical makeup suggest that humans are not carnivorous animals. Consuming only meat excludes the fiber necessary for us to maintain a healthy gut — one that is able to function without becoming backed up, causing constipation. Further, consuming high levels of meat, specifically red meat, has been linked to decreased cardiovascular health.

Are humans designed to eat meat?

The arguments surrounding whether humans are biologically obligated to eat meat are numerous and problematic. One oft-heard argument is that humans have canines and thus must be carnivores. The reality is that there are a number of herbivores, such as gorillas, with canines far more impressive and dangerous than our own. When it comes to teeth the ones that really matter are absent from our mouths. Carnivores sport carnassials that are blade-like and sharp, ideal for slicing; humans lack these teeth.

Are humans natural herbivores?

The evidence pointing toward the centrality of plants to the human diet far outweighs that supporting meat as a necessary component. Physically we display a number of different characteristics that reinforce the importance of plants and plant-based foods as an integral part of our diet.

Our teeth, jaws, and nails

Carnivores have mouths that open wide and their jaws are simply hinged. Humans, on the other hand, have the smaller mouths and fleshier lips characteristic of herbivores. Further, the joint of our jaw is more akin to that of a standard herbivore than that characteristic of carnivores. Our nails are also the blunt, flat variety of herbivores rather than the sharp, long claws of carnivores.

Stomach acidity

The acidity of the human stomach is similar to that of herbivores. Both humans and herbivores have a mildly acidic stomach pH between 4 and 5 when food is present, whereas carnivores have a far more acid stomach pH of 1 or less when digesting food.

Intestinal length

The length of human intestines is much more like that of herbivorous animals than that of carnivores. Humans tend to have intestines that are 10 to 11 times their body length. Herbivores, like humans, have long intestines of 10 to 12 or more times their body length — to provide ample space for digestion of plant matter. Carnivores, however, have short intestines of only 3 to 6 times their body length, accounting for only a small amount of the total capacity of their digestive system.

How did humans end up eating meat?

Scientists believe that it was climate change that originally caused the shift toward meat eating. As the earth grew warmer between 2.5 and 2.6 million years ago, our early ancestors were forced to shift away from a diet focused solely on plants to one that included animal protein as well. Even once our early ancestors began eating meat, they primarily scavenged the leftovers of larger predators instead of hunting for themselves.

Conclusion

Though humans may be able to thrive on either an omnivorous or herbivorous diet, the reasons to eat plant-based go far beyond human nutritional and physical propensities and characteristics. Choosing to eat a plant-based diet is one of the best decisions one can make for the environment and animal welfare. Every year billions of animals are slaughtered prematurely after a life filled with suffering. Thankfully, this doesn’t have to be the case. There has never been a better time to adopt a plant-based diet for the welfare of animals, the environment, and because doing so is a good decision for our own health and well-being. Though it may seem daunting, there are a number of tips and tricks you can follow to make the transition easier.