That's a load of rubbish
Ok, put in a better view point, I believe in the food-circle (The food-chain is flawed). Plants grow, herbivores eat the plants, carnivores eat the herbivores, carnivores die and their nutrients are returned to the earth, plants absorb these nutrients and the circle continues. The carnivore's role is to maintain the population of herbivores and prevent them from eating all the plants, which would break the circle. Mother nature wants us to be omnivores. That's why we eat meat
and vegetables. By being herbivores or carnivores we're defying the will of mother-nature, something humans are very good at.