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Serving Sizes

Author(s): Nancy Moreno, PhD, Barbara Tharp, MS, and Sonia Rahmati Clayton, PhD
Serving Sizes

A young girl learns about how to read food labels.
Courtesy of the US Navy\Riza Caparros.

  • Grades:
  • Length: 60 Minutes


Students estimate serving sizes of different foods and compare their estimates to serving size information provided on food package nutrition labels.

As part of this activity, students visit the PowerPlay exhibit at the Children's Museum of Houston. This lesson is best conducted after going to the Museum. Also, prior to the visit read "Teacher Tips," to plan the visit, and to learn about alternative options for conducting the activity without a Museum visit (see PDF).

This activity is from the PowerPlay Teacher's Guide. Although it is most appropriate for use with students in grades 3-7, the lessons are easily adaptable for other grade levels.

The PowerPlay project is a partnership between Baylor College of Medicine and the Children's Museum of Houston.

Teacher Background

The Children’s Museum of Houston’s PowerPlay exhibit is designed to help young people discover new ways to be physically active, and also to reinforce healthy behaviors. Healthy food choices are important to both objectives. Food labels and other guides often use “serving size” to describe a recommended single portion of a food. However, serving sizes vary among different kinds of foods (liquid versus solid food, and cooked versus raw food).

Frequently, the serving size listed on a food Nutrition Facts label—and the portion size actually eaten—are larger than the serving sizes suggested by other guides to healthy eating, such as the USDA Food Pyramid. Serving sizes provided on food labels are designed to make it easier for consumers to compare the calorie, carbohydrate and fat content of similar products, and to identify the nutrients present in a food. Used appropriately, food labels can help us to make better food choices.

Objectives and Standards

Texas Essential Knowledge and Skills (TEKS) Objectives


3.2.A-F; 4.2.A-F; 5.2.A-F

  • Student uses scientific inquiry methods during laboratory and outdoor investigations by collecting data, constructing charts and graphs, analyzing and interpreting patterns in data, repeating investigations for more reliability and communicating conclusions.

3.4.A; 4.4.A; 5.4.A

  • Students know how to use a variety of tools, materials, equipment, and models to conduct science inquiry.


3.1.A; 4.1.F; 5.1.E

  • Students will recognize and explain ways to enhance and maintain health and recognize and perform behaviors that reduce health risk throughout their lifespan.

Materials and Setup

Teacher Materials

  • 3 large containers of dry sample foods

  • 2-liter bottle of regular soft drink

  • 2 identical packages of each of the following: frozen peas, dry breakfast cereal, popped popcorn

Note: Remove the Nutrition Facts labels from all the food items. Create a “Nutrition Facts Labels” page by pasting all of the labels onto a sheet of paper (eliminate duplicate labels).

Materials per Group of Students

  • 6 paper plates (for dry foods)

  • 2 large cups or containers (for liquids)

  • 2 measuring cups (one for solids, one for liquids)

  • Permanent marker

  • Prepared copy of “Nutrition Facts Labels” (see “Note” above)

  • Copy of the “What is a Serving Size?” sheet

  • 4 copies of the “Estimates and Labels” sheet

Procedure and Extensions


  1. Ask students, What is a serving size? Use their answers to guide the class into a discussion of food portions.

  2. Explain that food portions usually are measured in terms of “cups,” pieces or other units. Show students the measuring cups they will use to measure dry and liquid foods. Point out that each unit commonly used in cooking can be translated into standard international (metric) units, such as liters or grams.


  1. After discussing food portions and serving sizes, challenge students to predict the serving sizes for the liquid and solid foods that you provide.

  2. Have one student from each group pick up the materials for his or her group. Give each group a copy of the “What is a Serving Size?” sheet. Have students follow the instructions on their activity sheets to label their plates and cups, and then predict appropriate portion sizes for each of the four foods.

  3. After students have recorded their estimates, allow each group to measure out and place the corresponding amount of each food into the cup or onto a plate labeled “Estimate.”

  4. Give each group a copy of the “Nutrition Facts Labels” page.

  5. Help students find the manufacturer’s suggested serving size on each food label. Then, have students measure out and place one serving of each food (as indicated on the label) into the cup or onto a plate marked “Food Label.” Have students observe and compare the amounts they estimated to be one serving size with the amounts actually listed on the food labels.


  1. Allow each group to share its findings with the rest of the class.

  2. Distribute a copy of the “Estimates and Labels” sheet to each student.

  3. Help students find other relevant information on the Nutrition Facts labels, such as details for diets with different caloric needs, and amounts of important nutrients in the food.

  4. Point out the “Quick Hand Measures” of portion sizes shown on the sheet. Ask, Do you think food labels can help you make better decisions about what and how much to eat?


To learn about “hidden sugar” in different foods and drinks, have students compare the amounts of sugar listed on the nutritional labels of fruit juices, soft drinks, cookies, cereal, baked goods and other foods (4g of sugar = 1 tsp).


  1. Ask students to bring in all types of food labels over the next week.

  2. Provide an assortment of labels to each group. Using the labels provided, have each group identify the food that fits each of the following categories.

    • Most fat per serving

    • Least fat per serving

    • Most calories per serving

    • Least calories per serving

    • Most protein per serving

    • Least protein per serving

    • Most carbohydrates per serving

    • Least carbohydrates per serving

    • Most sugar per serving

    • Least sugar per serving

  3. Discuss the results as a class.

Handouts and Downloads


Science Education Partnership Award, NIH

Science Education Partnership Award, NIH

Grant Number: R25RR022697