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I’m On a Diet & Proud of It: Nutrition through Math & Science

Activity 3 – How do living things get energy from food?

This lesson will teach students about calories as a measurement of the potential energy found in food and that everything their body does burns calories. In the end, students find out that nutrition is a team sport.

Learning outcomes

Students will:

  • Discuss how foods provide both energy and nutrients for living organisms
  • Utilize the basic information on food labels to make decisions about the nutritional value of nuts, apples, and soda
  • Develop fluency with multiplication and division

Teacher planning

Time required

40–60 minutes

Materials needed

  • Chart paper
  • 2–3 different types of nuts (recommend Brazil nuts, cashews, and peanuts)
  • Calorie counts for each nut used
  • Commercial calorimeter or make your own (see Calorimeter Directions)
  • Nutrition label for soda and apple

Technology resources

Optional: Compute with spreadsheet and/or graphing software. Measure with an electronic data collecting thermometer.

Pre-activities

  • Set up teacher demonstration of calorimeter.
  • Prepare class data chart on paper or computer.
  • Assign two students the role of data recorders, two students the role of timekeepers, and two students as observers. Each student pair will work as a team to record numerical data, keep track of the time, and record observations.

Activities

  1. Begin by reviewing previous activities and critical vocabulary. Then, set a purpose for learning by reminding students of the quest to figure out the nutrition facts label as well as to find out how food affects our bodies. Remind them that yesterday they found out how many calories their bodies needed. But how does the body get energy from food? Have students predict and write to this QOD.
  2. Tell students that calories are a measurement of the potential energy found in a food. Students should understand that calories help us know how much energy we can get from a food. The way that one knows how much energy is needed is based on what you do or your energy output. They should be balanced or equivalent. Note: Scientists define calorie with a small “c” as the amount of heat required to raise the temperature of one gram of water one degree Celsius. The term Calorie with a capital “C”, is most often used to describe the Caloric content of food. A Calorie is actually a kilocalorie or 1,000 little “c” calories.
  3. Use the following example; laughter burns approximately 3 calories a minute, while walking up the stairs uses 9 calories a minute. Everything one does uses calories — it’s like gasoline.
  4. Ask, “How many minutes would we have to laugh in order to burn off a 100 calorie pack of chips?”
  5. Ask, “What do you think will happen if you don’t use up all the calories you consume?”
  6. Optional: Watch and discuss the Discovery Health video National Body Challenge: Calories and Exercise (prefaced by an advertisement).
  7. Explain to students that calories that are not burned can eventually turn to unhealthy fat and weight gain because the body stores it for later use.
  8. Optional: Students may visit the calories burned calculator from Health Status to find out how many calories they are burning through other physical activities.
  9. Show students the various types of nuts you have available. Ask, “How can we find out which of these nuts has the most calories?” Most will say by looking at the nutrition facts label.
  10. Tell students that you do not have the labels, and will be conducting a teacher demonstration so that the class may collect data and find out which type of nut has the greatest number of calories. In general, per unit weight, higher Calorie content nuts burn longer and/or hotter.
  11. Direct attention to the data chart and calorimeter, while explaining the process you will carry out:
    How many calories are in a nut?
    Nut Burn Time Beginning Water Temperature Increase in Water Temp Calories
    Brazil nut
    Peanut
    Cashew
  12. Refer to Calorimeter Directions if necessary.
    Calorimeter directions
    Open as PDF (48 KB, 1 page)


    Take and record the water temperature. Place the shelled peanut on the point. Light the peanut with a match or lighter. As soon as it starts to burn on its own, place it under the can in the calorimeter, and allow it to burn. If the peanut sputters and goes out before it looks all burned up, get a new peanut, fresh water, and start over. As this is taking place with each nut, make sure the student observers are annotating what they see and hear, and the temperature of the water and time.

  13. When the nut looks all burned up and goes out, take the temperature of the water again. Record the temperature on the chart. Repeat for each nut.
  14. Calculate the Calories using the following formula.
    1. Determine amount of water used = (___milliliters = ___grams).
    2. Determine the temperature of water in degrees C before burning.
    3. Determine the temperature of water in degrees C after burning.
    4. Calculate the difference in temperature.
    5. Calories = (mass of water in grams) × (temperature change in degrees C)
      Example: 10 grams of water are heated 15 degrees C
      Calories = (10 grams of water) x (15 degrees C) = 150 calories
    6. Note: This calculation is in small calories. There are a thousand calories in a food Calorie, or large Calorie. To convert calories to Calories, divide the number of small calories by 1000.
      Food Calories or large Calories = small calories ÷ 1000
  15. Repeat the procedure with at least one other nut.
  16. Now bring out the nutrition labels for each nut and compare them with the results. You can use the search engine at the top of Self’s Nutrition Data website to find labels for most nuts. Students should see that the nut with the greatest number of calories on the label was the one with the most difference in water temperature change. It had the most energy — greatest number of calories. Ask, “How did this energy get in the nut?” Answers should be related to energy transfer through food chains.
    sun → pecan tree leaves → pecan nuts → human
    Note: This is a nice way to introduce the concept of food chains and energy transfer.
  17. Ask, “What does this mean for us?” Have a discussion on this topic.
  18. Then, ask, “Are all calories created equal? In other words, if I get calories from a soda or from an apple, are the calories the same? Why or why not?” Students will most likely say no, soda calories are bad while apple calories are good.
  19. Display the two nutrition labels for a soda and an apple and point out for students how both have similar amounts of calories. But a calorie is a calorie no matter where it comes from. The goal is to get more than just calories — we need to get nutrients too.
    Soda and apple nutrition labels
    Open as PDF (145 KB, 2 pages)


  20. Ask, “Which food has the greatest number of calories?” (soda) “What about nutrients?” (apple)
  21. Display comparison graph and lead a discussion into what it means. Ask, “Which would you eat? Why?” Students should understand that along with looking at calories, they must look at nutritional density. Explain nutritional density like this: A calorie is essentially worth more when accompanied by nutrients. Students will have the opportunity to explore this concept more in later activities.
    Nutrition comparison between an apple and a soda
    Open as PDF (338 KB, 1 page)


  22. Students should understand that a person is supposed to have a certain number of calories and nutrients each day. Ask, “If one eats food with many calories, but no nutrients, what is the effect?” Students should also understand that this often leads to overeating. Again this concept will be explored further in later activities.
  23. Optional: Direct students attention back to the nutrition labels for the nuts. Pose the question, “Which nut has the most nutritional density or which nut has the most nutrients and the least amount of calories?” Students may then use a spreadsheet or graphing software to display and compare nutritional information.
  24. To close, direct students to these essential questions:
    • What is nutrition?
    • How much am I supposed to eat?
    • How do we get energy from food? (energy transfer)
    • What happens when you eat too much or not enough?
    • What does it mean to be a healthy eater?
    • Are you on a diet? How do you know?
  25. Have a short discussion to review essential understandings for this activity and add student ideas to essential questions charts.

Assessment

  • Consider the class data chart from nut burning.
  • Take student observations into account.
  • Evaluate student responses to discussions and essential questions.
  • Students should record an answer to the QOD in their science notebooks that correctly applies essential understandings of the activity.
  • Optional: Comparison graphs of nutrition density of nuts can be assigned and evaluated.

Modifications

  • Students can further explore caloric intake versus caloric output.
  • Students can create personal food chains or webs showing where the energy in their diets originate, ultimately the energy coming from the sun.
  • Small groups of students can make a calorimeter and carry out the experiment. Make sure to have plenty of adult supervision on hand.
  • Discussion on nutritional density may be omitted or other learning experiences with density may be planned to explore this concept further.
  • Ask students to inspect nutrition label data prior to the nut burning. Direct students to use the data to preliminarily position the nuts in order from lowest to highest caloric content. Students then compare actual data to predictions and draw conclusions.

Alternative assessments

  • If necessary, a student’s answers to the various assessment tools can be given orally and/or dictated to a scribe.
  • Higher achieving students may be given this activity or portions of it to complete independently, while low achieving students may need to work in small groups and/or directly with the teacher.

Supplemental information

  • Student calorimeters can be obtained from Fisher-Scientific (product number S41746).
  • Food calorimeter can also be obtained from Fisher-Scientific (product number S78222).

Critical vocabulary

  • calorie
  • Calorie
  • kilocalorie
  • calorimeter
  • energy
  • input
  • output
  • combustion
  • chemical reaction
  • duration

North Carolina curriculum alignment

Healthful Living Education (2006)

Grade 4

  • Goal 4: The learner will apply knowledge and behavior self management skills to areas of nutrition and physical activity for healthy growth, development, and maintenance.
    • Objective 4.03: Utilize the basic information on food labels to make decisions about the nutritional value of various foods.

Mathematics (2004)

Grade 4

  • Goal 1: Number and Operations - The learner will read, write, model, and compute with non-negative rational numbers.
    • Objective 1.02: Develop fluency with multiplication and division:
      • Two-digit by two-digit multiplication (larger numbers with calculator).
      • Up to three-digit by two-digit division (larger numbers with calculator).
      • Strategies for multiplying and dividing numbers.
      • Estimation of products and quotients in appropriate situations.
      • Relationships between operations.
    • Objective 1.05: Develop flexibility in solving problems by selecting strategies and using mental computation, estimation, calculators or computers, and paper and pencil.

Science (2005)

Grade 4

  • Goal 4: The learner will conduct investigations and use appropriate technology to build an understanding of how food provides energy and materials for growth and repair of the body.
    • Objective 4.01: Explain why organisms require energy to live and grow.
    • Objective 4.03: Discuss how foods provide both energy and nutrients for living organisms.
    • Objective 4.05: Determine that foods are made up of a variety of components.
Supplemental Files: