BioEd Online

Teacher Background

Food labels and other guides often use “serving size” to describe a recommended single portion of a food. Serving sizes are different for various kinds of food (liquid versus solid foods, and cooked versus raw foods). In many cases, the amount specified as a serving size for a particular food is smaller than the amount typically eaten.

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

This activity introduces students to solid and liquid measures and to the concept of “serving size.”

Objectives and Standards

Life Science

• Plants and some microorganisms are producers—they make their own food. All animals, including humans, are consumers, which obtain food by eating other organisms.

Science in Personal and Social Perspectives

• Food provides energy and nutrients for growth and development. Nutrition requirements vary with body weight, age, sex, activity, and body functioning.

Science, Health and Math Skills

• Estimating dry and liquid measures of volume

• Estimating appropriate portion sizes

Materials and Setup

Teacher Materials

• 3 large containers for 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 and save the Nutrition Facts labels from all items (see Setup).

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” page (see Setup)

• Copy of “What is a Serving Size?" sheet (see Lesson pdf)

• 4 copies of “Estimates and Labels” sheet (see Lesson pdf)

Setup

1. Create a “Nutrition Facts Labels” page by pasting all of the labels saved from the food items above onto a sheet of paper (eliminating duplicates).

2. Display the three dry food items and the bottle of soft drink at a food station within the classroom.

3. Place all materials in a central location for Materials Managers to collect.

4. Have students work in groups of four.

Procedure and Extensions

1. Ask students, What is a serving size? Use students’ answers to guide them into a discussion of food portions. Explain that food portions frequently are measured in terms of “cups,” pieces or other units. Show students the measuring cups that they will be using to measure dry and liquid foods. Point out to students that each unit commonly used in cooking can be translated to standard international (metric) units, such as liters or grams.

2. After students have discussed food portions and serving sizes, challenge them to predict serving sizes for liquid and solid foods.

3. Have Materials Mangers pick up the materials for each 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 the plates and cups, and predict appropriate portion sizes for each of the four foods.

4. Once students have completed their predictions, allow each group to measure and place the corresponding amounts of each food into the cup and on the plates labeled “Estimate.”

5. After students have measured out the amounts of food representing their predicted serving sizes, give each group a copy of the “Nutrition Facts Labels” page.

6. Help students find the manufacturers’ suggested serving sizes for each food on the labels. Have students measure and place one serving (as indicated on the label) into the cup and on the plates marked “Food Label.” Have students observe and compare the amounts they estimated as one serving size with the amounts actually listed on the food labels.

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

8. Distribute a copy of the “Estimates and Labels” sheet to each student. Help students find other relevant information on the label, such as total calories needed and amounts of important nutrients. Point out the Quick Hand Measures of portion sizes on the sheet. Ask, Do you think food labels can help you make better decisions about what and how much to eat?

Extension

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

Handouts and Downloads

Download color images from The Science of Food and Fitness Teacher's Guide.