Science Activities: Calories as Energy for Our Bodies
Are Calories Good or Bad?
Take a survey of students about whether they think that calories are good or bad, encouraging students to raise their hands to respond. As a class, discuss what students know about calories and write down their thoughts on the board. Although some students will maintain that calories are bad, because they cause people to gain weight and can be unhealthy (when consumed in great amounts), other students will understand that calories give you energy. They might even say that that without calories, you wouldn’t have the strength to move.
Sum up the discussion by explaining that too many calories can be detrimental, but that calories are important. Note that all of the energy we get from food comes from calories, and that without calories our body wouldn’t have the energy to function.
Activity to Demonstrate How Calories Work
Explain to students that calories fuel the body just like gasoline fuels a car. Tell students that there are three main types of essential nutrients in food: carbohydrates, protein, and fat. Explain that each of these types of nutrients contains calories. The body breaks down the nutrients to release energy, just like the car breaks down the gasoline to release energy. Any nutrients that are not broken down are stored as fat. Ask students to use a Venn diagram to explain the similarities and differences between calories and gasoline.
A Calorie Math Exercise
Have students bring in nutrition labels from several different foods, both healthy and unhealthy. Explain to them that each gram of carbohydrates or protein contains 4 calories, and each gram of fat contains 9 calories. Have students cover up the “calories” line on their nutrition facts and try to calculate it based on the grams of carbohydrates, proteins, and fat in the product. Then have them uncover the calories line to find out whether or not their answer was correct.