Herbivores are designed to eat leaves. Carnivores eat meat. Omnivores eat both, switching as different food sources become common or scarce as the seasons differ.
Our feet are thought to be the most effective shock absorbers in nature - our elastic arch is better than that found on any other animal and shows that we were designed to cover large distances. We're hairless, which helps us cool down by sweating. Sweating means that don't need to pant like a dog to cool down, and being bipedal means that our breathing isn't tied 1-1 with our breathing pattern like a cheetah or a horse. Bipedalism also has another advantage that per stride we cover more distance than four legged mammals. Because of a multitude of energy saving, efficient adaptations like these, we can run longer than any animal on the planet and we are the ONLY ones that run long distances eg marathon for pleasure. We're highly specialised apex predators that persistence hunt our prey in groups. If we were built to forage and only eat plants and small mammals like rodents and rabbits, we wouldn't need these adaptations.
Nowadays, we're not going to starve if we don't eat meat, so we have the choice whether we want to contribute to the widespread abuse and poor treatment of animals that is farming, but it's silly to suggest we shouldn't eat meat because it's unnatural or barbaric etc. Sure it is, but that's who we are.