CBC Archives

Students will be familiar with the term “calorie,” but may not be familiar with the metric unit for energy, the joule (J), or the kilojoule (kJ). There are 4.2 kJ in one calorie. We use the energy that we get from our food to do all our daily activities from breathing and thinking to running and climbing stairs. Students will track their energy input for three days and try to compare it to their energy output for that time.

Have students view Clip #9, including The Story and the Did You Know? sections, on the topic Canada Gets Physical on the CBC Radio and Television Archives Web site.

Then have students work in pairs to design a food and activity diary that they will use for the next three days. Their food chart should include rows for meals and snacks, and columns to record serving size in grams and amount of energy in kilojoules.

The activity diary should be divided into 24 hours, and every hour into 15-minute quarters. Students should be able to account for every quarter as an activity type (sleeping, sitting, walking, standing, and so on).

Students should complete their diary over the next three days.

Ask students to write a paragraph to complete the phrase “I was surprised to find out….” As a class, students make direct comparisons between foods (for example, 24 g of milk chocolate = 1000 g of tomatoes), and between foods and activities. Ask: Which foods had a higher or lower energy content than expected? Which activities used more or less energy than expected? If chocolate has so much energy in it, why can’t we just eat chocolate as our primary food?