We all eat, right? But have you ever wondered why we eat? Some animals only eat plants, others eat other animals, and some eat both plants and meat. But the thing is, all animals, including humans, eat. And it’s not just because we’re hungry, bored, tired, or because food tastes good, although a slice of pizza does sound delicious right now!
We eat because we need food to live. More specifically, we need the energy that food gives our bodies to grow, move, and stay warm. You’ve probably heard things like “breakfast is the most important meal of the day” or that runners “carb load” before a big race. These are all about getting the energy we need from food.
Food is necessary for all living things, all the time. You might have noticed that your collection of cool rocks under your bed never needs a lunch of club sandwiches and baby carrots. That’s because they’re nonliving things. But food is definitely a necessity for animals and plants too. Even though we don’t think of plants as ‘eating’ because they don’t have mouths, they still need food to grow and repair themselves, just like we do.
Plants get most of their food from the sun, water, and carbon dioxide in the air. To see how food affects plants, we can test what happens when they get more or less food. You can use liquid plant food to control how much food or nutrients a plant gets.
Here’s a little investigation you can try. Say you have two little plastic cups filled with potting soil, and you plant a lima bean seed in each one. You give each plant a different amount of food. Plant number one will be your control, which means you don’t give it any additional food at all, just a little water and sunlight. It will do what plants do all on its own. Then, make plant two your extra food plant. Ask your parents for some liquid plant fertilizer and add the recommended amount to plant two.
If you keep watering and feeding your plants the same amount for, say, four weeks, what do you think will happen? Would you expect both of the plants to grow the same amount? Or would one grow more than the other? If so, which one?
What you’d find is that plant two grew bigger than plant one because living things need food to give them energy. This energy helps them repair themselves, stay healthy, and, in this case, grow. So with more food, plant two got more energy, allowing it to grow bigger.
Now, go eat your vegetables!
Food Energy Relay: Organize a simple relay race to help understand how food gives us energy. Create a small obstacle course in your backyard or living room. Before starting, discuss how different foods give us energy to move and play. As you run the course, think about how your body uses the energy from the food you eat to help you complete the race. After the race, talk about which foods you think give you the most energy and why.
Plant Observation Journal: Start a plant observation journal. Plant a seed in a small pot and place it in a sunny spot. Draw or write about your plant every few days. Notice how it changes and grows. Ask yourself questions like: What does the plant need to grow? How does it look different from when I first planted it? Why do you think it needs sunlight and water? This will help you see how plants use their ‘food’ to grow, just like we do.
Food Detective: Become a food detective and explore the different types of food you eat in a day. Make a list of your meals and snacks. Next to each item, write down what kind of energy you think it gives you (like energy to run, think, or play). Discuss with a family member why you think each food is important and how it helps your body. This will help you understand the role of food in giving us energy and keeping us healthy.
