Good Nutrition

Unit Overview
Nutrition Labels
Graphing
Percents
Formulas
Final Activities
Selected Resources
Credits




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Nutrition Labels
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Activity 1: Reading Nutrition Labels

Materials

  • transparency of Activity 1 Reference Sheet
  • calculators [optional]
  • nutrition fact labels from various food products

Activity Summary

Students will learn to read and interpret nutrition fact labels ("food labels") from food products, a task that involves the use of various mathematics skills (e.g., number concepts and number sense). Use with Activity 1 Reference Sheet.


Objectives

  • To stimulate thinking about good nutrition and to spark interest in understanding and monitoring one's own eating habits.
  • To read and interpret nutrition fact labels ("food labels") on food packages.

Introduction

Ask students how healthful they think their diet is, and why. In what ways do they monitor their eating habits, if any? What might they do to improve these? Why is a good diet important? (Address this not only in terms of its effects upon longevity and prevention of poor health in later life, but also in terms of its impact upon the quality of daily life at all ages by way of energy level, self concept, etc.) Tell students that they will be using mathematics-working with graphing, percents, and formulas/equations-to help them learn how to maintain a better diet. They will focus mainly on the macronutrients of fat, carbohydrates, and protein. These nutrients have the prefix "macro-" ("large") because they are the only three nutrients that we need in relatively large amounts and which, almost exclusively, provide the energy we need.

Make a transparency of Activity 1 Reference Sheet, and project it for students to see:

Girl Scout Cookies
Thin Mints
Thin Mints Label

Ask students:
  • What can you tell me about this food label?
  • About how many cookies are in one box of Thin Mints? (about 36) How do you know? (serving size of 4 cookies times about 9 servings per container)
  • How many grams of fat are in 2 cookies? (4.5g, because two cookies are half of the serving size for which the values are listed) 6 cookies? (13.5, or 1.5 times the serving size)

You might want to limit and keep simple any discussion of percent in the following questions, because the topic will be explored in some detail in Activity 3.
  • What percent of one cookie's calories comes from fat? (50%-20 of 40 calories) What fractional part is that? (1/2) Do you know what percent of your daily calories is recommended as the maximum amount of fat intake? (30%)
Allow students to use paper/pencil or calculators, as needed, in answering some of the following questions. Give them sufficient time to think through and explore various concepts before arriving at answers, and ask students to support their responses by explaining their reasoning before classmates indicate whether or not they agree with answers given.
  • What do you think the 13% at the end of the total fat row means? (For people who consume a fairly average amount of calories-2000 daily-it represents the percent of the recommended daily maximum intake of calories from fat that one serving size (four cookies) comprises. In other words, after four cookies are eaten-13% of the recommended daily maximum of calories from fat-a person on a 2000-calorie diet has 87% of her/his daily "fat calories" left to "spend." Do not dwell too long on this concept-it will be returned to in more detail in Activity 3.) Since 100% represents the "whole," or total amount of fat a person takes in each day, the serving size of four cookies makes up about what fraction of the total amount of fat allowed in one day for a more healthful diet? (a little more than 1/8* ) Explain how you know this. (100% divided by 13%-recommended daily maximum divided by one serving-is about 8; or, 13 out of 100, represented by the fraction 13/100, is a little more than 1/8) How many cookies would you have to eat to reach the maximum recommended fat allowance (assuming you're on a 2000-calorie diet)? (about 31*) Explain. (8 times the serving size of four cookies is 32, but since one serving size is a little more than 1/8 of the day's fat allowance, 31 cookies is more accurate.*)
    *Note that, because of rounding error stemming from values listed on the food labels, different answers can be obtained. If a student answered the questions based on the facts that the total fat for one serving is 9 grams and the total fat intake for a day (2000-calorie diet) should be 65 grams or less (see lower part of label), the answers change to one serving size being a little less than 1/7 of the total daily fat and the number of cookies consumed in reaching the daily fat maximum would be about 29.
  • The percent daily values are based on a diet of how many calories? (2000) Where do you find this information? (table near the bottom) If the number of recommended calories for your diet is 2200, do you think you could eat more grams of fat than the 65g recommended for the 2000 calorie diet and still have a healthful diet? (Yes, 30% of 2200 calories is about 73 grams of fat. Students will learn later how to determine such values in Activity 3.)

Student Activity

Give each pair of students a nutrition facts label (or a photocopied label) from a food product-preferably different labels to different pairs. Have each pair work together to create a set of questions similar to those discussed as a class for the Thin Mints. (You might want to designate a range, e.g., 5-10 questions, the specific number depending on the complexity of the questions and the number of subquestions within each.) When finished, each pair should exchange their label and questions with another (designated) pair. Each pair should work together-preferably using a calculator-to answer the other pair's questions on paper. The pairs should then exchange the label/ questions/answers for the original pair to assess the other's work, afterwards returning the work to the pair who completed it and discussing errors/disagreements as needed.

Tell students that they should be prepared to discuss afterwards difficulties encountered while doing the activity, confusion experienced, interesting findings, and so forth. Students might be asked to write some of these on paper while they are waiting for their designated exchange pair to complete work and/or after they finish the activity.

Closing Discussion

Conduct an open-ended class discussion about the previous activity. Have students share some questions they asked or were asked that differed from the type asked in the class discussion that preceded the activity. You might want to examine the methods used (and others that could have been used) to answer particular questions. Also address such items as:
  • difficulties encountered
  • areas of confusion
  • interesting findings



© Copyright
Area 10 Mathematics and Technology Professional Development Center
Permission is granted to duplicate these materials for classroom use.

Last updated on 1/30/1999
Comments: egalindo@indiana.edu
http://www.indiana.edu/~atmat/units/nutrition/nutr_t1.htm