An Investigation of Nutritional Requirements under Extreme Conditions
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Author Contact Information
Sandra Kolb, Educational Consultant, Poulsbo, Washington (email@example.com)
Rick Griffith, Fairview Jr. High, Central Kitsap School District, Silverdale, Washington
Students will investigate nutritional requirements for intense physical exercise under extremely cold conditions. They will plan a nutritionally correct menu for their body weight and nutritional requirements as if planning for their own expedition.
By developing skills in teamwork and planning, this activity will allow students to understand the relevancy of how intense physical exercise and cold affects nutritional needs while skiing across Antarctica.
explain how the body uses fats, sugars, carbohydrates, and proteins
state the kilocalorie value of a unit mass of fats, sugars, carbohydrates, and proteins
plan and organize a nutritionally correct daily expedition menu
demonstrate teamwork skills
develop an evaluation tool
Grades 7/8, Life Science and Mathematics
National StandardsUnifying concepts and processes in science
Science as inquiry
Science in personal and social perspective
Pre-activity set-upEstablish contact with an expedition/s
Determine for each student: body weight, basil metabolism, exercising heart rate and kilocalorie requirements to maintain constant body fat. (Note: Sometimes body weight can be a sensitive issue for students. Give students the option to weigh privately during an out of class time.)
Locate science or health texts for chapter on nutrition.
kilocalories and how the body metabolizes food
Point out: A young person of average weight and activity needs about 2,500 kilocalories per day of food to maintain body weight and stay healthy. This energy is nearly the equivalent to burning a 120-watt light bulb. (Later on when students contact Antarctic expeditioners who burn 6,000 kilocalories a day, they will use a simple ratio to determine that these expeditioners are like a much brighter light bulb burning energy at the rate of 290 watts. This difference in heat can be felt at one foot.)
Experiment: If your school allows fire, have students burn a walnut (or other oily nut) and measure the heat contained by heating a known mass of water. Record the temperature change. Students will then be able to link intense physical exercise needs and energy requirements.
Basil Metabolic Rate (BMR): The rate energy is used when a person is totally at rest is called Basil Metabolic Rate (BMR). Like a car, think of it as the body idling. Because muscles use more energy than fat, males typically have a 10-20% higher basal metabolic rate (BMR) than females. On the average, short, chubby people tend to have a lower BMR than tall, thin people. This is because more energy is lost through the skin of people with larger body surfaces.
Measuring Body Fat: One method of determining the percentage of body fat is to use a caliper. This is an instrument that looks like a handcuff and measures the thickness of skin. The area of the body usually measured with a caliper is the triceps muscle. This is located at the back of the upper arm and is halfway between the shoulder bone and the elbow. The subscapular area immediately below the shoulder blade is also commonly measured.
The “pinch test” can be roughly used to determine obesity and is comparable to the caliper. A fold of skin on the back of the upper arm or at the hipbone directly below the waist is pinched. If this fold is more than one inch in thickness, then there may be too much body fat.
Determining Kilocalories Needed to Maintain Weight: To determine the average number of kilocalories a person needs to maintain one’s body weight under normal temperature conditions, the following computations need to be made.
First, basal metabolic calories (BMR kilocalories) can be approximately determined as body weight times 10 for women and body weight times 11 for men. This value is then multiplied by a factor for level of activity to determine activity kilocalories: 0.30 for inactive life styles to 0.75 for very active, strenuous lifestyles. Kilocalories needed for digestion are determined by adding BMR kilocalories + activity kilocalories and multiplying by 0.1.
Total kilocalories needed to maintain body weight are: BMR kilocalories + activity kilocalories + kilocalories needed for digestion
For example: Joanna weighs 123 pounds. To maintain her body weight under a strenuous regime of activity she needs BMR: 123 x 10= 1230 kcal + Activity kilocalories: 1230 x 0.75= 922.5 kcal + Digestion kilocalories: (1230+922.5) x 0.1= 215.25 kcal or a total of about 2367.75 kcal per day.
Due to extremely cold temperatures, this will be a higher value in Antarctica because BMR is higher in cold climates. The body requires more energy to produce heat under cold conditions.
Determine kilocalorie value of a unit mass of fats, sugars, carbohydrates and proteins
MaterialsStop watch or clock
Bathroom scale clock
Computers with internet access clock
Poster paper and colored markers for presentations, optional clock
Block of cheese, peanut butter, trail mix, dried fruit, granola bars, power bars, pop tarts, marshmallows
Time FrameFour to five 50-minute class periods teaching nutrition
Three to four 50-minute class periods student team planning including the development of evaluation criteria and a rubric
One 50-minute class period for expedition team presentations and evaluation
Engagement and Exploration (Student Inquiry Activity
From the experiences of Sandra Kolb, "During the austral summer I was working at the Amundsen-Scott South Pole Station, 5 Trans Antarctic ski expeditions arrived. Four of these expeditions skied with specially prepared and pre-measured packages of dried food labeled for specific meals and each containing a specific number of calories and weight. This sounds really scientific, doesn't it? One expedition was not so exact. They were from a European country known for its cheese. They took as they said, "just a bunch of food" and far too much of it--especially cheese because they really, really liked it. Cheese is heavy and bulky. They found this out as they pulled their sledges skiing across Antarctica. To lighten the sledges they started tossing cheese out along the way. I have visions of cheese preserved forever in the ice only to be discovered and analyzed as a relic thousands of years from now!"
Field these questions:
Do some foods weigh more than others? Why?
What types of food provide both well-balanced nutritional energy and weigh less than cheese
Some examples of foods students might suggest (have these on hand or any others that you may choose):
Read the nutritional guides on packages of the above food items.
Lead a brief discussion and come to a consensus as to which food provides the most well-balanced and nutritional calories.
Read and briefly talk about the nutritional information on the block of cheese.
Using a food scale weigh the block of cheese and an equivalent volume of a food item the class agreed upon. Which is lighter? The cheese or the agreed upon food item? Which provides the best nutrition?
Explain while discussing:
Do you think you eat more in the summer or winter? Why?
Do you get hungrier sitting around or when you exercise? (Students will probably say that they get hungrier when they exercise. Point out that with exercise hunger comes later and you eat more. To maintain a constant body weight, there is a balance between food intake as measured in kilocalories and activity level as measured in kilocalories.)
Young people of average weight and activity need about 2,500 kilocalories per day of food to maintain body weight and stay healthy.
Pretend you are in Antarctica. Do you think you would need more or less kilocalories to maintain your present weight? What are the variables?
Guide the students to understand that the following factors influence the amount of kilocalories needed to maintain body weight:
level of activity
clothing and insulation
natural metabolism (based on genetics and gender)
What types of foods do you think you need to eat while on an expedition in Antarctica? These foods must meet your caloric and nutritional needs.
What nutrients does the body need to continue its healthy functioning and in what foods/food groups are these nutrients found?
Present the following scenario:
Ask students to image they are going on an expedition to Antarctica. In expeditions of 2-4 people, they will ski 1,500 km. to the Amundsen Scott South Pole Station in optimal conditions of ~48 days. They need to take all their food with them. To prepare for such an expedition they need to investigate nutritionally correct menus for surviving it.
Once the scenario is introduced, hold a classroom discussion on possible evaluation criteria of this project. Brainstorm and list on a transparency or other visual aid.
Come to a consensus on 3-5 criteria. For example:
thoroughness of preparation
visual aid (optional poster or chart)
Next develop a simple rubric (i.e. check-sheet format of: excellent, good, fair, poor) for the evaluation of this criteria. This process will take about one 50-minute class period.
Self-selected student teams of 2-4 students plan to ski 1,500 km. to the South Pole Station in optimal conditions of ~48 days investigate a nutritionally correct menu for surviving such an expedition. Students determine their body weight and the types and amounts of foods required daily under the extreme conditions of cold and exercise. Students use the Internet to make contact with one past and/or present expedition to inquire about its daily nutritional requirements and types of foods consumed.
Elaboration (Polar Applications)Follow on a daily basis or contact at least one polar expedition on the expedition's web site.
Read Sandi Kolb's Jan. 19,1999 journal entry, "Letter 9: Visitors", at ../../Archive/kolb/kolbletters_jan_19.html . In this letter, look for clues about the number of kilocalories consumed per person per day and the total weight of this food.
Optional: Read any teacher selected required reading on polar expeditions available in the classroom or school library.
Exchange (Students Draw Conclusions)
Through individual team discussion and presentations to the class, student panelists explain what happened and why it occurred during their planning process and the outcomes of their project. Optional: visual aid such as a poster or chart.
Evaluation (Assessing Student Performance)Evaluation criteria was determined and a rubric developed prior to the beginning of the student team planning.
Student panels (the "expeditions") present with each student presenting a section of their project.
Teacher and student groups (optional) evaluate each presentation using the class rubric. Optional teacher choice to include student evaluations in grading.
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