Answer
According to the 10% rule of energy efficacy, only 10% of energy gets transferred from the previous trophic level to the next one in the energy pyramid. Thus eating a pound of tofu will provide more energy than eating a pound of hamburger.
Work Step by Step
The energy content follow decreasing trend from the first trophic level to the next one. Tofu, which is derived from a plant, primary producer, will have more energy in ecological terms as it is present at the base of the productivity pyramid. The hamburger, which contains cow beef, primary consumers, is present one level up in the productivity pyramid and will have lower energy than tofu in ecological terms.
