Good Nutrition

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




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Activity 3: Percents
(Student Copy)

Materials

  • calculators
  • Activity 3 Reference Sheet pages 2+

Part A

Use Activity 3 Reference Sheet Labels A-J to answer the following questions.
A)
  • Without doing actual computations on paper or with a calculator, write the letters of the snacks that you think have a percent calories from fat that is greater than the recommended 30% maximum.


  • Describe your general method for arriving at answers to the previous item.

  • List any of the snacks that you think have 50% or greater calories from fat.


  • Describe your general method for arriving at answers to the previous item.

  • Which two snacks do you think have the largest percentage of calories from fat?

  • Which two snacks do you think have the smallest percentage of calories from fat?
    Which two do you think have the next smallest percentage?

B)

  • Choose four snacks and find the percent calories from fat for each using one serving as your reference. You may use a calculator. Find answers to the nearest percent (i.e., round to the hundredths place).

  • Describe how you solved the problems in the previous item. If you used the same method for two or all three of them, you may describe that procedure just once (refer to the problems you solved, if needed)

C)
  • What minimum percent of a food should not come from fat?
  • What percent of Chee-tos does not come from fat?

  • Look at the Hostess Lights Low Fat Cup Cakes nutrition label. How do you think it's possible for the percent calories from fat to differ for one and two cakes?


Part B

1. The type of food label you looked at in Activity 1 was made mandatory for most packaged foods beginning in 1994. You have already taken advantage of one major change-figuring percent calories from fat. Finding that value was more involved on the old labels, which did not list the calories from fat. To figure the percent calories from fat, consumers had to know that there are about 9 calories in one gram of fat, so they had to multiply the number of grams of fat times 9 and then figure the percent.

  1. Looking at Activity 3 Reference Sheet Labels A-J, tell whether or not this rule "works" for each of the following. Explain why it did or did not work.

    Triscuits

    Hershey's Kisses

    Country Club Ice Cream

  2. Did the rule work for all of the items?

    If not, why do you think this is so?

2. Consumers interested in knowing the percent calories of protein or carbohydrates of a packaged food must use a procedure like the one described in number 1 above, because food labels list the grams for each of these nutrients but not the calories. Each gram of protein or carbohydrate has about 4 calories. Therefore, you can see why fatty foods contribute to weight gain much more readily than those consisting of large proportions of the other two macronutrients (proteins, carbohydrates). You learned in Activity 2 that current recommendations are that about 60% of a person's calories come from carbohydrates and 10% from protein.

  1. Look at Activity 3 Reference Sheet labels K-W. Using mental computation or estimation only--and remembering that protein and carbohydrates have 4 calories per gram--tell which items, if any:

    get about 10% of their calories from protein?

    get more than half (50%) of their calories from carbohydrates?

  2. Complete the chart below using one serving as the standard. List the number of grams (g) for carbohydrates ("Carb") and protein ("Pro"), the number of calories ("cal") for each, and the percent of the total calories ("% cal") that each comprises. As an example, the Stove Top Stuffing Mix for Turkey (1/2 cup prepared with margarine) has 20 grams (g) of carbohydrates. Multiply that by 4 to find how many calories the carbohydrates comprise, and you get 80. Out of 170 calories, 80 calories is 47 percent (170 80, rounded to the nearest hundredth). Protein is found using the same procedure.

Food Carb
(g)
Carb
(cal)
Carb
(% cal)
Pro
(g)
Pro
(cal)
Pro
(% cal)
Raisin
Bran
Lender's
Bagels (Plain)
Healthy Choice
Bean & Ham Soup

3. Use a calculator to fill in all missing values in the chart that follows. For the carbohydrates for the taco, estimate the percent only (leave grams blank). Round numbers to the nearest whole number. Remember that 1 gram of fat is about 9 calories, and carbohydrates and protein are each about 4 calories per gram.

Macronutrients: Percent Composition of Total Calories
(Source: Nutrition charts provided by the listed restaurants)
Food Item
Macronutrient/
Grams Per Serving
Total Calories
(1 serving)
Percent of
Total Calories
Subway:
12" Ham & Cheese Sub on White
  • fat/
  • carbos/80.59 g
  • protein/37.73 g
643.33 cal
  • f: 25%
  • c: 50%
  • p:
Taco Bell:
Taco
  • fat/11 g
  • carbos/not listed
  • protein/
180 cal
  • f:
  • c:
  • p: 22%
McDonald's:
Big Mac
  • fat/27 g
  • carbos/49 g
  • protein/24 g
  • f: 50%
  • c: 40%
  • p: 20%
Kentucky Fried Chicken:
Drumstick (1), Extra Tasty
Crispy
  • fat/12 g
  • carbos/
  • protein/14 g
190 cal
  • f:
  • c: 13%
  • p: 29%
Pizza Hut:Pan Pizza
(2 slices med. cheese)
  • fat/18 g
  • carbos/57 g
  • protein/30 g
  • f: 33%
  • c: 46%
  • p: 24%
Wendy's:
Jr. Bacon Cheeseburger
  • fat/
  • carbos/33 g
  • protein/22 g
440 cal
  • f: 51%
  • c:
  • p: 20%


Note: Some restaurants, such as those above (mainly fast food types), provide nutrition fact charts upon request. If restaurants do not have nutrition guides to hand out, they might have them posted on the wall or available for you to see.

4. Did any of the nutrition facts in the chart surprise you? If so, which ones and why?

5. If you added pepperoni to the pizza, which nutrient(s) do you think would increase most in terms of percent calories out of total calories?


6. Which one or two of the six foods do you think is most nutritious (it is probably more accurate to say "least unhealthy"!)? Explain.


7. What types of things should be considered in comparing the foods in the chart (in terms of nutrition) in order to choose one for a meal?


8. How did you estimate the percent calories from carbohydrates for the taco?


9. How is it possible for the percent totals for the sub, the chicken, and the bacon cheeseburger to total somewhat below or above 100%?


10. Describe a general rule for finding the following missing values in the chart, assuming you know the two values in the other columns:

  1. grams per serving (first column)


  2. total calories (second column)


  3. percent of total calories (third column)


Part C

You might have noticed that food labels include a column called "% DV" or "% Daily Value." These values are figured for a daily caloric intake of 2000 calories and are used as a reference in determining what percent of your daily total (i.e., 100%) each nutrient provides (of the daily total recommended for that particular nutrient). For example, a person on a 2000-calorie diet should have no more than 30% of those calories from fat. Thirty percent of 2000 is 600 calories, which-divided by (about) 9 calories per gram-yields a little less than 67 grams and is listed as 65 grams on food label reference charts. So, a person on a 2000-calorie diet should get no more than 600 calories, or 65 grams, of fat in her/his daily diet. Talk about this with your partner or group members and be sure you understand the concept before going on.

Assume a 2000-calorie diet for the following items.
  1. About how many grams of carbohydrates should a person consume daily? (Refer to Activity 2, if needed, to recall what percent of a healthful diet comes from carbohydrates.) Explain how you get your answer.


    • One cup of Wheaties (dry) has 24 grams of carbohydrates. What percent of the daily value is that? Explain.


    • What percent daily value of carbohydrates remains to be consumed on that day?

    • If a person on a 2000-calorie diet eats one serving of Doritos (Nacho Cheesier brand) [1 oz., or about 11 chips], which has 7 grams of fat, what percent daily value does that represent? Explain how you found your answer--see if you can find more than one method.


    • Approximately what fraction of the daily value is that?


    • How many more grams of fat can she or he consume to reach her or his daily limit (Daily Value)? How do you know?


    • What percent of the daily value for fat calories still remains? Explain.


Extension/Follow-Up




  1. What do you think the Mystery Food is on Activity 3 Reference Sheet, Label W?
  2. Determine the maximum number of calories and grams of fat, carbohydrates, and protein (Daily Values) recommended for a daily caloric intake that is appropriate for you (charts can be found that list recommended caloric intakes based on age, sex, body type, level of physical activity, etc.).
  3. Is it possible for a %DV (percent Daily Value) to be higher than 100%? Explain.
  4. Explain what you think 1/2% means.
  5. Alcohol is an energy source, but it is not a nutrient because it serves no required function. Nonetheless, alcoholic beverages rank third as a source of calories in the American diet. Find how many calories are in one gram of alcohol.


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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_s3.htm