One quick look into the body of a true carnivore will show you that humans are herbivores and have adapted to be omnivores, but we're not built to successfully eat animal flesh. We do take advantage of our dominion over them to catch them by any means we can, but we are not anatomically built to eat animals.
One of the least educated arguments I've heard against veganism is the, "humans were made to eat animals" theory. People tell me this quite seriously and I think they truly believe that our bodies are designed to devour other animals.
True carnivores are built with specialized body parts to help them kill, rip apart, and digest other animals. One of the easiest ways to demonstrate this concept is through pictures- take a look at our body parts and compare them to the parts of carnivores like sharks, lions, tigers, falcons, hawks, eagles, crocodiles, wolves, foxes, and polar bears. Are they closer to the parts on herbivores like horses, donkeys, goats, sheep, cows, zebras, elephants, rhinoceroses, deer, and rabbits?
Carnivorous animals often use their limbs to assist with catching and killing of prey and thus have sharp claws, talons, or nails made to latch onto another animal, hold them down, and rip them apart.
Omnivores and herbivores have flat feet with blunt fingernails to protect their fingers from objects bumping or poking them. Sound familiar?
Humans have soft hands with thin nails that protect our fingertips. Nothing like the talons and claws used to grip and tear at flesh...
Carnivores have sharp, thick teeth used to tear flesh into large chunks. Think of lions, tigers, and sharks that have extra layers of teeth so that when they aggressively rip apart an animal and their teeth break, they have extras for the future.
Omnivores and herbivores have flat teeth used to grind and mash food. Herbivores don't have sharp incisors because we don't need to tear animals apart. If we eat something too hard or stiff, our teeth break and aren't replenished with new ones.
Do your teeth look like these?
Or are they more like these?
Here's a quick reminder...
Carnivores have a short digestive tract which allows meat to escape the body before rotting inside.
Omnivores and herbivores have long digestive tracts which allow the body to break down protein, fats, and carbohydrates.
Also in the interest of clearing food as quickly as possible, carnivores are designed with smooth digestive tracts, without any bumps that could trap the meat and cause it to sit and rot in their stomachs. They don't need fiber to help process their food; it just slides through the digestive tract.
Herbivores have bumpy digestive tracts with pockets which allow plant matter to get caught and take longer to be digested so all the nutrients can be absorbed into the body. Herbivores need to eat fiber so they can successfully push food through the digestive tract.
Carnivores have high acidity in their stomaches and in their saliva, which helps to break down animal food.
Herbivores have alkaline saliva and stomach acidity to help process plant matter slowly, pulling out all the nutrients.
Humans actually have adapted to be able to eat both meat and plants, turning us into omnivores, even though our bodies are much more similar to herbivores. Now, in the wild, this would mean that we would eat mostly plant matter and would eat a very small amount of meat matter. In today's society, this is completely flip-flopped in the other direction.
Most people eat mostly meat products. You may think I am exaggerating, but think of all the milk, eggs, and meat that you actually eat. Usually it's a breakfast, lunch, dinner, dessert, and snack thing. We eat tons of it without even realizing it. And, we don't eat nearly enough plant matter.
Because humans are herbivores, our bodies simply crave more of the plant matter. Without it we develop diseases and die at younger ages.