National Agricultural Literacy Curriculum Matrix
FoodMASTER Middle: Energy Balance
6 - 8
Two 1-hour activities
Students will identify the importance of a healthy diet, examine how to meet current Dietary Guidelines, and determine the potential energy (kilocalories) of a peanut through measurements obtained during teacher use of a bomb calorimeter. Students will make comparisons to the actual Nutrition Fact Label and identify possible sources of error.
- Magnificent Menu student handout, 1 per student
Teacher Materials, demonstration (see step 6 in lab procedures)
- Safety goggles
- 1 empty soda can
- 1 empty metal coffee can (large enough to fit a soda can inside)
- 1 cork
- 1 uncoated paper clip (any size)
- 1 graduated cylinder
- 100mL distilled water (room temperature)
- 1 thermometer (Celsius)
- 1 lighter
- 1 forceps
- 1 peanut for calorimeter
- 1 glass or metal rod (16cm or longer)
- 1 can opener with a triangular end (church key)
Student Materials, per group of 4-5 students
- Energy Equilibrium student handout, 1 per student
- Energy Balance lab sheet, 1 per student
- 1 small bowl 1 graduated cylinder or liquid measuring cup
- 1 triple beam balance
- 100mL distilled water (room temperature)
- 1 cup of peanuts
Essential Files (maps, charts, pictures, or documents)
- Energy Balance Teacher Key
- Energy Equilibrium student handout
- Energy Balance Lab Sheet
- Energy Equilibrium Teacher Key
- Managing Your Meals Teacher Key
- Managing Your Meals student handout
bomb calorimeter: a vessel for measuring heat of combustion by igniting a sample
calorie: a unit of heat energy; the amount of heat required to raise the temperature of one gram of water one degree Celsius. It is used to indicate the amount of energy that foods will produce in the human body.
energy balance: the biological homeostasis of energy in a living system; relation between intake of food and output of work; when balance is positive, the body stores extra energy as fat; when balance is negative, the body uses stored energy (fat), resulting in weight loss
joule: a unit of work or energy equal to the work done by a force of one newton
kilocalorie: the standard unit used to describe the amount of energy that foods will produce in the human body and is reported on Nutrition Facts Labels
Did you know? (Ag Facts)
- A calorie is a unit of measurement — but it doesn't measure weight or length. A calorie is a unit of energy.1
- Calories first began being used as a unit of measurement in food in the 1800s.2
- A gram of fat usually contains about 9.44 calories. A gram of protein contains 5.65 calories.3
Background Agricultural Connections
Interest Approach – Engagement
- Conduct a short class discussion by asking students what health benefits come from consuming a balanced diet. Students should seek to identify specific food groups, their health benefits, and common food sources of each.
- Give each student one copy of the Magnificent Menu student handout. If completed in-class, allow students to work in small groups on Investigation worksheet to further explore the topic and respond to questions.
- Follow-up with a class discussion about student findings related to the health benefits of consuming a balanced diet and student generated ideas for making their own diet “balanced.”
Lab: Energy Balance
- Review information found in the Background Agricultural Connections section of the lesson, lesson Procedures, and the attached Essential Files.
- Prepare student materials for each group. If time is a concern, construct the bomb calorimeter before hand and pre-weigh the single peanut.
- Note the following:
- The mathematics within this lesson may be challenging to some students. Consider guiding students through the mathematics portion of the lab, or assigning one student within each group to lead others through the work.
- A portion of this lab investigation (burning of food) should occur in an open area outside unless you have access to a fume hood in your classroom.
- WARNING: Students with peanut allergies may not be able to participate in this investigation.
- Construction of the of the Bomb Calorimeter:
- Choose one of the following methods:
- Option 1: Use the triangular end of a can opener to put four holes evenly spaced around the bottom edge of the coffee can. One hole should be large enough to fit a peanut through.
- Option 2: Remove the bottom of an open coffee can.
- Drill or poke holes (the size of a pencil eraser or smaller) through a small aluminum can (soda) opposite each other about 1 cm below the top. Do not remove the top. The water and thermometer can be placed into the can through the drinking opening.
- Insert a glass or metal rod, 16cm or longer through the holes you made at the top of the soda can. This rod will support the can when it is placed across the top of the coffee can.
- Note: If using Option 1 construction, placing the soda can on the base of the coffee can instead of hanging it should provide a sufficient temperature increase.
- The bomb calorimeter is now ready for the lab. See step 6 of the lab procedures below for further steps.
- Choose one of the following methods:
- Consider having your students research kilocalories as a unit of measuring energy in food prior to beginning the lab investigation.
- Distribute lab materials. It is recommended that materials are organized into stations for easier distribution. Students should be arranged in small groups of 4-5. Each group should receive the lab supplies outlined in the Materials section as well as 1 copy of the Energy Balance lab sheet and one copy of the Energy Equilibrium student handout.
- Ask students to read Energy Equilibrium and complete the "Think About It" questions for this lab investigation.
- Before beginning the lab investigation:
- Require students to wash their hands.
- Emphasize the importance of practicing good food safety behaviors by not consuming substances used as part of the lab investigation.
- Launch the lab by asking students to observe and make a prediction about the kilocalorie content of peanuts.
- Next, complete the teacher demonstration or show the provided video lab demonstration, Food Explorations Lab: Energy Balance. If you use the video, make sure students record the measurement values provided in the appropriate tables. If performing the demonstration in class, follow these steps:
- Begin by weighing and recording the mass of a single peanut. This same peanut will later be placed into the bomb calorimeter. Students should record the weight in Table C. If you completed this step ahead of time, simply provide students with the weight of the single peanut.
- Next, place 100mL of room temperature distilled water in the soda can.
- Place the soda can inside of the coffee can.
- Unwrap the paper clip and insert it in the cork.
- Wrap the paper clip attached to the cork around the peanut. If the peanut breaks off while it is burning, you will have to burn a new peanut. Be sure to re-weigh the peanut each time.
- Light the peanut with a wooden match or lighter. Once it ignites, immediately place the coffee can around the burning peanut or insert it through a hole in the bottom of the calorimeter.
- Make sure the peanut burns completely. If the fire goes out, re-light the peanut.
- WARNING: If you have to relight the peanut, be careful to use caution when touching the heated coffee can.
- Once the peanut has completely burned, stir the water with the thermometer and measure the temperature. Both cans may be warm. Be careful not to burn yourself.
- After the burned peanut has cooled, measure and record its weight. Students should record the weight in Table C.
- Allow students to work in small groups to complete the Energy Balance lab sheet and respond to lab questions. Note that if you used a thermometer that measured in Fahrenheit instead of Celsius, before proceeding with the conclusion questions you will need to help students convert degrees Fahrenheit (°F) to degrees Celsius (°C): °C = 5/9 *(°F -32). You may consider completing this math for students or guiding them through the conversion. An example of the °F to °C conversion, as it relates to conclusion question #1, is provided for you below. The water temperatures provided in the equation below are for example purposes only.
- Follow-up with a class discussion about the relationship between human health and consuming nutrient dense (foods high in nutrients, low in calories - e.g. vegetables/ fruits) versus calorie dense foods (foods high in calories, low in nutrients - e.g. French fries, soda). See Enriching Activities for ideas on how to further extend this lesson.
5/9 (70°F (ΔT) − 32) = 21.11°C
5/9 (71°F (ΔT) − 32) = 21.67°C
(21.67°C after burning peanut) − 21.11°C before burning peanut) = 0.56°C water (ΔT)
100 gram water . 1 cal/g/°C . 0.56°C = 56 cal (Q) or 0.056 kcal
Concept Elaboration and Evaluation
After conducting these activities, review and summarize the following key concepts:
- Potential energy is stored energy that has not been used. The amount of potential energy varies among foods.
- A calorie is the amount of energy needed to raise one milliliter of water one degree Celsius. The energy contained in the food we eat is measured in calories.
- Consuming too little energy will cause our bodies to breakdown too much stored energy, leading to malnutrition. Consuming too much energy will cause our bodies to store too much energy, leading to obesity. We need to consume a balanced diet to ensure the best health outcomes.
Explore the energy density of other foods by using the bomb calorimeter or reviewing Nutrition Facts labels.
Suggested Companion Resources
- Eat & Move O-Matic (Multimedia)
- Choose MyPlate (Website)
- Food-A-Pedia (Website)
- National Geographic: What the World Eats (Website)
Agricultural Literacy Outcomes
Food, Health, and Lifestyle
- Evaluate food labels to determine food sources that meet nutritional needs (T3.6-8.b)
- Identify agricultural products (foods) that provide valuable nutrients for a balanced diet (T3.6-8.g)
Education Content Standards
MS-LS1 From Molecules to Organisms: Structures and Processes
MS-LS1-7Develop a model to describe how food is rearranged through chemical reactions forming new molecules that support growth and/or release energy as this matter moves through an organism.
MS-PS1: Matter and Its Interactions
MS-PS1-2Analyze and interpret data on the properties of substances before and after the substances interact to determine if a chemical reaction has occurred.
Common Core Connections
Reading: Anchor Standards
CCSS.ELA-LITERACY.CCRA.R.1Read closely to determine what the text says explicitly and to make logical inferences from it; cite specific textual evidence when writing or speaking to support conclusions drawn from the text.
CCSS.ELA-LITERACY.CCRA.R.10Read and comprehend complex literary and informational texts independently and proficiently.
CCSS.ELA-LITERACY.CCRA.R.3Analyze how and why individuals, events, or ideas develop and interact over the course of a text.
CCSS.ELA-LITERACY.CCRA.R.4Interpret words and phrases as they are used in a text, including determining technical, connotative, and figurative meanings, and analyze how specific word choices shape meaning or tone.
CCSS.ELA-LITERACY.CCRA.R.7Integrate and evaluate content presented in diverse media and formats, including visually and quantitatively, as well as in words.
Speaking and Listening: Anchor Standards
CCSS.ELA-LITERACY.CCRA.SL.1Prepare for and participate effectively in a range of conversations and collaborations with diverse partners, building on others’ ideas and expressing their own clearly and persuasively.
Writing: Anchor Standards
CCSS.ELA-LITERACY.CCRA.W.2Write informative/explanatory texts to examine and convey complex ideas and information clearly and accurately through the effective selection, organization, and analysis of content.
CCSS.ELA-LITERACY.CCRA.W.7Conduct short as well as more sustained research projects based on focused questions, demonstrating understanding of the subject under investigation.
CCSS.ELA-LITERACY.CCRA.W.9Draw evidence from literary or informational texts to support analysis, reflection, and research.