Everything that is alive needs energy. All animals get the energy they need from food. People are animals. Think about the human body as an amazing machine. It can do all kinds of things for us, Food is the fuel that helps keep the amazing machine running. Plants use sunlight to make their own food. Animals are not able to do that. Some animals eat plants. Some animals eat other animals as meat. Some animals, like people, eat both plants and animals. Since plants make their own food using sunlight, the sun's energy is found in plants. The sun's energy is very strong. It loses a lot of its strength by the time it goes into a plant When we eat plants, we get more of the sun's energy than when we eat animals. That's why it is good to eat fruits and vegetables. When an animal eats a plant, the energy is less strong. The animal also used its energy to find the plant to eat. When a second animal eats the first animal, it gets even less energy than the first animal got. The second animal used a lot of energy to chase its prey. Like a car that has to be filled with gasoline, living things have to eat again and again. Instead of gasoline, living things use food as fuel.