What Is the Fat Intake of a Typical Middle School Student?

Transcription

1 What Is the Fat Intake of a Typical Middle School Student? Health professionals believe that the average American diet contains too much fat. Although there is no Recommended Daily Allowance for fat, it is recommended that fat intake be limited to 30 percent of total calories. You have been keeping a food intake diary for a week now. As you look back at the week, do you find that you are eating within this guideline for fat consumption? Below, you will find a method to help you calculate the percent of fat in your diet so that you can use your data to arrive at a conclusion. Then, conduct an investigation among your peers to determine if your intake is typical. Collect your information in an organized manner. Determine if the typical middle school student adheres to this guideline. Report your findings in a way that shows the scope of your investigation. How reliable are your data? Do you have proof of the amount of fat consumed by the typical middle school student in your community? Figuring the percent of fat in the diet: Number of grams of fat x 9 calories per gram = Total number of calories from fat 1 of 30

2 Total number of daily calories from fat Total number of daily calories = Percent of calories from fat Example: An adolescent who eats 2,000 calories per day, which includes 80 grams of fat, could figure the percent of his or her diet that was from fat. 80 grams of fat x 9 calories per gram = 720 calories from fat 720 calories 2,000 calories = 36 % from fat per day 2 of 30

3 Suggested Grade Span 6 8 Task Health professionals believe that the average American diet contains too much fat. Although there is no Recommended Daily Allowance for fat, it is recommended that fat intake be limited to 30 percent of total calories. You have been keeping a food intake diary for a week now. As you look back at the week, do you find that you are eating within this guideline for fat consumption? Below, you will find a method to help you calculate the percent of fat in your diet so that you can use your data to arrive at a conclusion. Then, conduct an investigation among your peers to determine if your intake is typical. Collect your information in an organized manner. Determine if the typical middle school student adheres to this guideline. Report your findings in a way that shows the scope of your investigation. How reliable are your data? Do you have proof of the amount of fat consumed by the typical middle school student in your community? Figuring the percent of fat in the diet: Number of grams of fat x 9 calories per gram = Total number of calories from fat Total number of daily calories from fat Total number of daily calories = Percent of calories from fat Example: An adolescent who eats 2,000 calories per day, which includes 80 grams of fat, could figure the percent of his or her diet that was from fat. 80 grams of fat x 9 calories per gram = 720 calories from fat 720 calories 2,000 calories = 36 % from fat per day Big Ideas and Unifying Concepts Cause and effect Change and constancy Systems 3 of 30

4 Life Science Concepts Regulation and behavior Structure and function Science in Personal and Societal Perspectives Concept Personal health Mathematics Concepts Algebra Average Data collection, organization and analysis Division Graphs, tables and representations Multiplication Percents Ratio and proportion Statistics Time Required for the Task Once the class data have been collected, it takes about two class periods (50 minutes each) to complete. Context My mathematics students had been studying nutrition in Family and Consumer Science class for a few weeks. I was teaching a statistics unit and wanted them to have an opportunity to collect, organize and analyze data related to the unit of study on nutrition. One favorite topic of early adolescents is themselves, so I thought this would be an engaging and interesting inquiry task for them. Next time, I would begin by asking students to make a prediction about their fat intake and the fat intake of the middle school students in their community. Then, they would design and conduct the investigation to test their hypotheses. What the Task Accomplishes The students keep track of their total food intake for one week. At the same time, they need to keep track of the caloric count and the grams of fat per serving of all the foods they eat that week. They then need to calculate the percentage of fat in their diets using the formula given on the task sheet. The second phase of the task involves each student listing her/his average percent of fat consumption for the week on a class data chart. This gives each student the data needed to compare personal percentages against the class average. The individual student can 4 of 30

5 then decide to carry the investigation further, to test other classes that are not studying nutrition, or a group of students from another school, in another community, or another state or country. How the Student Will Investigate The students need at least a week to collect data in their food diaries and to determine their personal percentages. I had them keep the diary before I gave them the task. The problem was that they weren t keeping track of the actual quantities of food eaten and calculating percentages as they went along. I think it would work better if the resources were available as they went along and they calculated every day. What you would lose by doing it that way is the blindness of their eating patterns. If they were calculating percent of fat every day, would that affect their eating patterns? This is an excellent example of the need for a discussion of experimental design at the beginning of the students investigation. What are the things that might affect data being collected? Students need good directions about keeping a food diary. They need to be aware of serving sizes, the fact that they need to record everything they eat yes, even the milk on the cereal! This will take a week. They then need to use the formula given and calculate the percent of fat in their diet each day to get their weekly average. They then need to decide if they are within the guidelines and determine the average for a larger group of adolescents and decide if that group is average or typical in their fat consumption. Interdisciplinary Links and Extensions Science Family and Consumer Science (the old Home Economics): Students could reorganize data in terms of the food pyramid and draw correlating conclusions between fat intake and types of foods eaten. Perhaps, the students would want to collect data on food intake comparing a vacation week to a school week, asking, Is there a difference? What patterns can I see? Or draw comparisons between a vegetarian and nonvegetarian diet. Students might also research the effects of changes in fat intake on the other systems in the body and on life expectancy. Using the results of their individual data, they could analyze and make adjustments to their own dietary habits, collect data for at least one week, and recalculate the percentages to look at cause-effect of regulating food/fat intake. Mathematics If you have modem access and are studying a state or country that is connected to the Internet, it would be very interesting to exchange data and compare your class averages with those of a group of math students from another culture. Explore the use of other ways to organize data. Social Studies Current Events: Make some predictions about the large-scale effect of too little or too high fat intake on a population (e.g., explore situations such as the current famine in North Korea or the dietary effects of the Bosnian war). If students are studying other times/cultures, they could look at diet, nutrition and fat intake as contributing factors to life style and life expectancy. 5 of 30

6 Teaching Tips and Guiding Questions Students need lots of guidance in keeping the food diary. Both the Family and Consumer Science teacher and I were working with them and still there were individuals with errors. A letter home enlisting parental assistance would be a good idea (and a good way to educate families as well). Many foods that the students are eating have the necessary information on the labels, and if they are reminded to look at the label at the time of consumption, it will save a lot of hassle later! I decided that giving them the formula as part of the task was the best idea (following the lead of New Standards mathematics tasks). Some students still needed to be walked through it step-by-step. I have 48 students and wrote their names on a single sheet on the flip chart, with a space for their average percent of fat for the week. Students could then opt to use any part of the class data they chose. I had recently taught them to make stem and leaf plots to organize data and box and whisker plots to represent data, and you will see in the student work that some opted to represent their data using these methods. There was a computer program available, which some students took advantage of to calculate their percentage of fat. The program also suggested lower fat alternatives to the menus they entered. These programs are available through computer software catalogs; also check with your Family and Consumer Science or health teachers. Some guiding questions might be: Are you beginning to see any patterns in your data? Is there a better way to organize your data? Looking at the class data, are there significant patterns of differences between males and females? Is there a correlation between the type of foods eaten and the amount of fat in them? Were there days/times that your fat intake was higher/lower? Was it related to your activity level? your mood? the day of the week? What foods seem to be the healthy-choice foods, and why do you think so? How does this investigation relate to eating a well-balanced diet? Concepts To Be Assessed (Unifying concepts/ big ideas and science concepts to be assessed using the Science Exemplars Rubric under the criterion: Science Concepts and Related Concepts) Life Science Structure and Function; Regulation and Behavior: Students see that there is a correlation between healthful living/choices and systemic maintenance. Science in Personal and Societal Perspective Personal Health: Students understand that the amount of energy a person requires varies and is related to age, weight, sex, metabolic rate and activity level, and that some dietary habits may be bad for one s health some effects showing up right away and others not for many years (cause and effect). Students understand that changing dietary habits is within each individual s control. 6 of 30

7 Mathematics: Students use equations to summarize how the quantity of something changes over time (change and constancy). Students understand the concepts of ratio, proportion, percents and average and apply algebra, division, multiplication and statistics skills. Students collect organize and analyze data and use graphs, tables and representations appropriately. Skills to be Developed (Science process skills to be assessed using the Science Exemplars Rubric under the criteria: Scientific Procedures and Reasoning Strategies, and Scientific Communication Using Data) Scientific Method: Collecting, recording, organizing and analyzing data; making conclusions based on data analysis; creating statistical tables and charts; predicting; observing; and communicating. Other Science Standards and Concepts Addressed Scientific Method: Students hypothesize, investigate, describe and explain phenomena. Scientific Theory: Students look for evidence that explains why things happen and modify explanations when new observations are made. Life Science Structure and Function: Students observe a correlation between healthful living/choices and systemic maintenance. Life Science Regulation and Behavior: Students understand that some dietary habits may be bad for one s health some effects show up right away and others not for many years and that all parts of the system can be affected by any other part. Science in Personal and Societal Perspectives Personal Health: Students explain that the amount of energy a person requires varies and is related to age, weight, sex, metabolic rate and activity level, and that life expectancy can be increased through monitoring and regulating these variables. Mathematics: Students understand number and operation concepts (addition, subtraction, multiplication, division and changing decimals to percents and interpreting percents as part of 100). Students understand measurement (mass, volume, capacities) and statistics (appropriate use of measures of central tendency mean, mode, median). Suggested Materials Each student should have graph paper and a notebook or journal to record his or her fat intake via the foods eaten. (You might want to develop a short checklist for all students to use in collecting data.) To compute percentages, calculators or computer programs may also be used. 7 of 30

8 A variety of reference books listing calorie and fat gram content of foods are helpful when the information does not appear on the packaging or if students eat out. (There are several available, all slightly different. Check with your librarian and school nurse for what you have in your school.) Possible Solutions Solutions will vary based on the foods eaten by each student during the recording time. Data collected need to be complete a full week of recording all foods eaten. Calculations need to be accurate (using the formula provided), data collection needs to be organized in a meaningful way, and conclusions need to be based on data. Students should describe what parts of the class data were used, and discussions/conclusions should address possible experimental error. Task-Specific Assessment Notes Novice There is little evidence of a strategy or the reasoning used to arrive at the calories and fat grams in the food eaten. (The student arrived at 32 percent personal intake, but on page three, it looks as though s/he added only the seven numbers bracketed. That would not give a sum of 1142.) Data collection is not complete a week of foods eaten has not been recorded, and no quantities are included for the items listed. Conclusions are stated but not referenced or supported by the data and mathematical representations. Experimental design/possible errors or personal eating habits are not discussed. Apprentice Data collection is not complete, but meals are labeled separately. A full week of foods eaten has not been recorded; no quantities are included for the items listed. The student makes reference to pizza being the highest in fat content of foods eaten evidence of beginning to see patterns in data. There is a major gap in the solution from the calculation of 80 grams x 9 calories = 720 calories from fat to his/her average being 31 percent. There is evidence of reasoning present, but all mathematical procedures are not fully completed. There is appropriate mathematical representation,ree but it is inaccurately labeled. Conclusions are stated and referenced in the data and mathematical representations. Experimental design/possible errors are not discussed. Practitioner Data collection is complete; a full week of foods eaten has been recorded, but no quantities are included for the items listed. This student shows broad understanding of the problem and the major concepts necessary for its solution. His/her strategy leads to a solution, and there is effective mathematical and scientific reasoning, especially as evidenced by an acknowledgment of the bias of the experimental sample. (There is an error in the identification of the median on the box and whisker plot.) S/he communicates the solution clearly, using clear and appropriate representations. Conclusions are stated and referenced in the data and mathematical representations. 8 of 30

9 Expert Data collection is complete; a full week of foods eaten has been recorded. The student uses a scientific tool, the computer, to verify the accuracy of calculations. (It is necessary for him/her to input the serving sizes, but this is not displayed in the print out.) This student shows a deep understanding of the task. S/he acknowledges that the sample of respondents is biased and offers suggestions for carrying the investigation beyond that bias. The strategy is efficient in that the student entered data on a daily basis. S/he did an excellent job of verifying the results by calculating the mean, mode and median of the data set and commenting on that comparison. Conclusions and explanation are clear and detail how the problem was solved. All of the steps are included, so there is no need for the reader to infer how or why decisions were made. The student's representations are clear and accurately support the results. 9 of 30

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