Student Information Page 5A

Transcription

1 Fat Minder : How to Keep an Energy Balance Activity Introduction: Student Information Page 5A Fat Minder come in many sizes and shapes. Their purpose is to help you understand the relationship between the energy you take in and the energy you use up during a day. This relationship is responsible for determining the amount of body fat we store. In this activity, you will create a Fat Minder and use it to calculate the number of calories you would have to take in to produce the amount of body fat contained in your Fat Minder. You will also calculate how much exercise you would have to do to get rid of that much body fat. Finally, you will determine amounts of food that contain enough Calories to cause your body to store a mass of body fat equal to the mass of your Fat Minder. Using Archimedes Principle, you will determine the volume of your Fat Minder. This technique is used to measure the volume of irregular objects and it involves submerging an object in water and measuring the resulting rise in water level. The water rise will equal the volume of the object submerged. Activity Background: In our modern day lives, we are reminded to live a healthy life-style and watch our weight; in fact 66% of American adults are overweight or obese. Television, technology, and magazines remind us of watching our weight and staying active. While fat is necessary for insulation and energy, unhealthy accumulation of fat around our waist, hips or abdomen could be precursors to diseases, such as arthritis, some cancers, diabetes and heart disease. Achieving a healthy weight can help prevent these weight-related diseases. Achieving a healthy weight means keeping an energy balance between the energy we take in and the energy we burn up each day. Eating too much or not being physically active will make you overweight. To maintain your weight, the calories you take in with your food must equal the energy you burn. To lose weight, you must use more calories than you eat. A weight-control strategy might include: Choosing low-fat, low-calorie foods Eating smaller portions Drinking water instead of sugary drinks Being physically active We all talk about Calories, but what does the word mean? A calorie refers to the energy stored in food. It is amount of energy required to raise the temperature of 1 gram of water 1 degree Centigrade. When discussing the energy content of 2007, 2013 The University of Texas Health Science Center at San Antonio 5

2 food, a Calorie (note it is capitalized) is actually a kilocalorie or 1000 calories (note it is written in lower case). This is the amount of energy required to raise 1 kilogram of water (about 2.2 pounds) 1 degree Centigrade. Why does a tablespoon of ice cream have more calories than a tablespoon of non-fat milk? Because different foods contain different amounts of energy depending upon what is in those foods. Our bodies can break down food molecules to release the energy stored within them. We need this energy for such things as movement, blood circulation, and growth generally just staying alive. Our bodies store extra energy in fat cells for future use. The amount of energy we require each day is determined by our activity level, age, weight, and height. Here s the basic information you need to begin this activity. It takes 3500 Calories to add one pound of body fat. If you eat 3500 Calories more than your body uses, you will gain one pound of body fat. If you use 3500 Calories more than you eat, you will lose one pound of body fat. Activity Materials: (per Fat Minder ) Sculpy clay (small amount in zip-loc bag) 3/4 c dry plaster of Paris (pre-measured into Styrofoam bowl) 1 c tap water (approximately) 1 sturdy Styrofoam Bowl 3 small Styrofoam cups 2 small paper plates 2 sturdy plastic spoons 2 toothpicks Red auto gasket silicone (small amount placed on paper plate just before being used) Clear 100% Silicone caulking (approximately 2 spoonfuls placed in small Styrofoam cup just before using) 1 drop yellow acrylic paint 1 triple beam balance ml plastic graduated Beaker (with the smallest increments possible so to accurately measure volume displacement) 1 copy Student Information Page 1 copy Student Data Page (per student) 2007, 2013 The University of Texas Health Science Center at San Antonio 6

3 Procedure: Part I: Making Your Fat Minder Read each statement and check off as completed. p 1. Sculpt your Fat Minder out of sculpy clay using Figure 1 Clay Model as a guide. This works best by forming small, irregular spheres of clay to simulate fat globules. The spheres can then be stacked together to achieve the desired look. You can even give your Fat Minder a face by using a little creativity! Figure 1 Clay Model p 2. Allow clay model to sit while preparing the plaster of Paris. p 3. Put 1/2 c water in the small bowl and add enough plaster of Paris to create a thick paste, (the consistency of soft-serve ice cream). Stir, adding more water or more plaster as needed. The resulting consistency should flow easily, but not be runny. p 4. Pour the plaster of Paris over the clay Fat Minder. Work the plaster of Paris over the sides of the clay Fat Minder until the plaster of Paris begins to harden. Be sure all clay is covered. Allow the plaster of Paris to dry (depending on size, drying may take 2 4 hours). See Figure 2 Molds Drying. Figure 2 Molds Drying p 5. Carefully, remove the clay from the hardened plaster. You have now created a Fat Minder mold. See Figure 3 Remove Clay. Pre-measure red silicone and yellow paint, see Figure 4 Remove Clay. p 6. Place a small amount of red silicone on your finger and lightly run it over the ridges inside of the mold. Figure 3 Remove Clay p 7. Add approximately 2 tablespoons of silicone to the second bowl. Add a drop of yellow paint and stir until evenly mixed. Silicone should be a light yellow, buttery color. p 8. Carefully, add yellow silicone to the inside of the mold. Use the plastic spoon to push the silicone into all crevices of the mold. Keep adding silicone to the inside of the mold until all crevices are filled and all ridges covered (You do not have to completely fill to the top). p 9. Allow the silicone-filled mold to sit undisturbed overnight. Figure 4 Pre-measure Red Silicone and Yellow Paint 2007, 2013 The University of Texas Health Science Center at San Antonio 7

4 p 10. Carefully, remove the silicone Fat Minder from the mold and trim any excess silicone off the bottom of the Fat Minder. See Figure 5 Trimming Fat Minder. p 11. After the lab investigation, you can add Googly Eyes for added character by using a small dab of clear silicone to attach the eyes. Attach your Fat Minder to it s coaster using silicone as the glue. See Figure 6 Finished Product. Part II: What does the Fat Minder have to do with me? A. Storing fat in your body Figure 5 Trimming the Fat Minder TM p 1. Using a triple-beam balance, carefully find the mass of your Fat Minder. To ensure accuracy, repeat three times and find the average. p 2. Record the mass in grams in the data table in the Student Data Page. p 3. Using the formula provided on the Student Data Page, calculate how many calories you would have to take in order for your body to store a mass of fat equal to your Fat Minder. Figure 6 Finished Product B. Losing fat from your body p 1. Following the instructions given in the Student Data Page, use the formula to calculate how much exercise you would have to do in order to lose the amount of fat equal to your Fat Minder. p 2. Record this information on your Student Data Page. C. Mass, Volume and Density of your Fat Minder p 1. Using a graduated beaker at least three times the size of your Fat Minder, determine the volume of your Fat Minder. p 2. Fill the graduated beaker with enough tap water to completely cover your Fat Minder. The graduated beaker should not be more than 1/2 full. If it is more than 1/2 full, you will need a larger beaker. p 3. Place the beaker with tap water on a flat surface. Carefully, read the volume of water in ml and record this measurement on the Student Data Page. p 4. Now, drop the Fat Minder into the beaker filled with water. You will notice that it will float in the water. In order to measure the total volume of your Fat Minder, you must be sure that it is completely submerged in the water. 2007, 2013 The University of Texas Health Science Center at San Antonio 8

5 p 5. Using a pen or pencil, gently push the Fat Minder under water be sure none of the pen or pencil is submerged in water or you will be measuring part of its volume as well. p 6. Carefully read the volume of the water and Fat Minder and record the number on the Student Data Page. p 7. Subtract the starting volume (without the Fat Minder ) from the final volume (water and Fat Minder ). This will equal the volume of your Fat Minder. p 8. Using the information on the Student Data Page, you will calculate the density of your Fat Minder. Density is the mass of an object divided by it s volume. p 9. A very similar procedure is used to determine the amount of body fat in people! See if you can find out about hydrodensitometry. Part III: What does the Fat Minder have to do with food you eat? p 1. Look at the table of common foods on your Student Data Page. p 2. Determine how much of each food you would have to eat in order to take in enough calories for your body to store a mass equal to the mass of your Fat Minder. Part IV: Now your Fat Minder can help you remember that maintaining a healthy level of body fat is all about energy balance. p 1. Research body fat facts, which we will call Fatoids. You will need to find ten Fatoids to keep with your Fat Minder. p 2. Keep the Fat Minder in a place where you often eat to help remind you to keep the right balance of Calories and Exercise! 2007, 2013 The University of Texas Health Science Center at San Antonio 9