In a food chain, the amount of energy transferred to the succeeding trophic level is only 10%. The remaining energy is wasted as heat to the environment. Let us consider the following food chain: Producer (plants) $$\rightarrow$$ Primary consumer $$\rightarrow$$ Secondary consumer $$\rightarrow$$ Tertiary consumers So, the producers (plants in this case) will have the maximum amount of energy. Of this, only 10% of energy gets transferred to the next trophic level i.e., a vegetarian person. Now, if a person is non-vegetarian, they obtain their energy from other animals that are either primary consumers or secondary consumers. Hence, the amount of energy received from them is even more reduced. Thus, a vegetarian person is at an advantageous position as they obtain energy directly from the producers, compared to the non-vegetarian person.