Energy balance act lesson plan Unit 1Document Transcript
Pennington Biomedical Research CenterAwesome.2Cents! A Healthy Lifestyle Curriculum for Teens…Grades 8-12Lesson # 1: The Energy Balancing ActContent outline An overview of Energy Balance What determines the energy in and energy out components What happens with energy imbalances over time? Tips to maintain energy balanceLouisiana content standards: 1-H-1, 1-H-2, 1-H-4, 1-H-5, 1-H-6, 2-H-2, 3-H-1, 3-H-2, 3-H-4, 3-H-4, 6-H-1, 6-H-4 1-M-2, 3-M-1, 3-M-2, 4-M-2, 5-M-4, 5-M-5Objectives/Expected Learner Outcomes Students can identify the three components of energy expenditure. Students can identify the characteristics that contribute to energy expenditure. Students can learn to calculate daily energy expenditure.Lesson and Strategies Student group targeted 7-12th gradeTime required Teacher Preparation: 15-20 minutes Assessment: 10 minutesMaterials and Resources Power point presentation: The Energy Balance Act Projector Screen Laptop/Computer Energy Balance Assignment/Answer Key Physical Activity Assignment/Answer Key Physical Activity Energy Costs Handout Calculating Percent of Energy AssignmentTeacher PreparationMake copies of the Calculating Percent of Energy Assignment, Physical ActivityAssignment and the Energy Balance Assignment to pass out to students in class. Thecalculating percent of energy assignment and the physical activity assignment are to becompleted during class, with the energy balance assignment being a homework assignment.
Slide Lesson Plan1 The Energy Balancing Act What’s it all about? Say: This lesson is about energy that we consume and energy that we burn when we move.2 Say: This lesson will cover: An overview of Energy Balance We’ll talk about what it is and why it’s important. What makes up the components of energy balance What happens with energy imbalances over time? Discuss how to maintain energy balance at 0 so we won’t gain or lose weight over time and discuss tips and ideas3 Say: Energy balance--What’s that got to do with me? The truth is that energy balance is an important concept for everyone to learn about—no matter how old or how young you are. First, we need to go over what we mean by balance? You can view energy balance the same way that you would view a scale, or even a seesaw. For example, What would happen if you were at a playground and decided to go and sit down on one side of an unoccupied seesaw? Do: Encourage students to answer. (Answer = that side of the seesaw will fall to the ground) Say: So, the seesaw would be out of balance, right. You would need someone else to come and sit on the other side. If you can find someone to come and sit down, but they are much heavier than you are, then what happens to your side? Do: Encourage students to answer. (A= your side goes higher because you weigh less) Say: Again, the seesaw is out of balance. Next, you put your feet on the ground to hold yourself in place. What if someone sat down who had the same weight as you? What would happen? Your friend who weighs more steps off and another one steps on. This friend weighs basically the same as you. As you lift your feet back up off of the ground, What happens now to your side? Do: Encourage students to answer. (Answer = it becomes level with your friends side). Say: This seesaw example is a lot like how energy balance is—except instead of people on either side of the seesaw (or scale), we have energy input on one side and energy output on the other. But what does that mean? What determines how much
input you’ll have and what determines how much output? This is the very thing that we will go over next.4 Energy Input – Where is it coming from? Say: On one side of the energy balance equation are foods and other side has energy we expend. This is your energy input (calories going into your body). Everyone needs to eat food in order to survive. It is through the metabolism of nutrients found in the foods that we eat that we receive chemical energy to operate our bodies. But, of course—we need to balance what goes in (energy input) our body with goes out (energy output), or else we’ll have all of this excess energy in our bodies. Can anyone tell me what the 3 macronutrients are in our diets (meaning the three nutrients found in food where we derive our energy from)? Do: Encourage students to answer. (Answer= carbohydrates, protein, and fat) Say: For most people, about 43 to 58 percent of daily calories come from carbohydrates, about 30 to 45 percent of calories come from fats, and about 12 percent come from proteins. You might ask, how do I know how many calories from fat, carbohydrate and protein I consume for a given day? I will provide an example on how to do that in just a moment.5 Say: The first thing that you need to know is how many calories each gram of fat, protein and carbohydrate supplies. What is the first thing that you notice on this slide that is different between fat and the other two nutrients, carbohydrates and protein? Do: Encourage students to answer. (Answer = fat provides more kcal for every gram that is consumed than does carbohydrate or protein Say: It is true that fat is more calorie (or energy)-dense than carbohydrate and protein. But, this most definitely does not mean that we need to eliminate fat altogether from our diets. Fat is an important component of our diet that has many important roles in the body. The type of fat that we eat [trans and saturated vs. unsaturated fats] is very important, even more so than the amount, although we still do want to keep our intakes of fat at moderate levels.6 Let’s talk about the different types of fat we just mentioned: Saturated – solid at room temperature (butter, lard), causes hardening of arteries and hardening of all cell walls. Cell walls are full of lipid and we want most of it to be unsaturated. Unsaturated fat – liquid at room temperature (oils). When we consume mainly unsaturated fats, most of the fat in our cell walls will be unsaturated and this helps keep our cells walls fluid and allows different substances to enter and exit
which is particularly good for delaying and preventing the development of diabetes. Trans fat – Produced during food processing, occurs in ready - made foods such as cakes, crackers. Increases bad cholesterol (Low density lipoprotein or LDL) in the blood.7 Say: Raise your hand if you like pizza. (allow students time to respond). For our example, we will look at the percent of calories from total fat, carbohydrates, and protein in 2 slices of Pizza. In one serving of pizza (which is technically 2 slices), there are: 280 kcal 14 grams of total fat 28 grams of carbohydrates and 11 grams of protein Say: The first thing that we will do is to calculate what percent of energy comes from fat in one serving of the pizza. If there are 9 kcal for every gram of fat, then we need to multiply the amount of fat found in the 2 slices of pizza (which is 14 grams of fat) times 9. So, that would be 14 times 9. Do: Write on the board 14 grams of fat x 9 kcal/gram of fat = 126 kcal. Also, be sure to indicate to the students that grams of fat cancel out and that you are left with calories only. Say: What we just figured up was the number of calories in 2 slices of pizza that came from fat. Next, we need to know the actual percent of calories that came from fat. We would do this by dividing the number of calories from fat by the total calories in the serving of pizza that we ate. This would be 126 divided by 280. Do: Write on the board (underneath the last part) 126 kcal/280kcal = 0.45 Say: We get a decimal of 0.45. Does anyone know what we need to do to make this a percent? Do: Encourage students to answer. (Answer = multiply the decimal by 100) Say: Yes, and once we do this, we find that in this meal, 45% of the calories came from fat (total fat). Next, we will calculate the percent of calories from carbohydrates in this meal. Remember, that there are 4 kcal for every gram of carbohydrates. In this example, the meal (which is 2 slices of pizza) has 28 grams of carbohydrates. So, we need to multiply the total grams of carbohydrates in this meal times 4 (28 times 4).
Do: Write on the board 28 grams of carbohydrates x 4 kcal/gram of carbohydrate = 112 kcal. Note that when you multiply, grams of carbohydrates cancel out and you are left with kcal only. Say: We find that there are 112 calories from carbohydrates in this meal. Next, we need to figure up what percent of calories came from carbohydrates. We do this by dividing the number calories provided by carbohydrates in our meal by the number of total calories in the meal. This is: 112 divided by 280. Do: Write on the board: 112 / 280 = 0.40. Say: Once we multiply this decimal by 100, we find that 40% of the calories in this meal are from carbohydrate. Finally, we will calculate the percent of calories in this meal from protein. Remember, that like carbohydrates, protein also has 4 kcal per gram. In this meal, there are 11 grams of protein, so in order to determine the number of calories from protein we would need to multiply 11 grams of protein by 4 kcal. Do: Write 11 grams of protein x 4 kcal/gram of protein = 44 kcal on the board. Again, note that grams of protein cancel out, leaving you with kcal only. Say: In this meal, there are 44 kcal from protein. To calcualte the percent of kcal from protein in this meal, we need to divide 44 kcals (calories from protein in the meal) by the total number of calories in the meal, 280. Do: Write 44/280= 0.1571 Say: When we multiply this decimal by 100, we get an answer of 15.7 which can be rounded to 16%. This tells us that 16% of the calories in this meal come from protein.8 Energy Input Say: Now, we are going to calculate how many calories came from fat, carbohydrates, and protein in another example. But this time instead of using a meal as an example, we will use an entire days worth of meals and beverages. Here is our example: On Monday, Jane consumed 1,800 calories, 65 grams of fat, 240 grams of carbohydrates, and 55 grams of protein. I’m going to give you a handout with this information on it, and will allow you time to work through it. Remember what we learned: 1 gram of fat = 9 kcal; 1 gram of carbohydrate= 4 kcal and 1 gram of protein = 4 kcal. If you have any questions, just let me know. ------------------------------------------------BREAK--------------------------------------------- Do: Pass out the Calculating Percent Energy from total fat, carbohydrates and protein handout. Allow students time to work through the example. Walk around the
room and assist any student having problems. Here is how to work the example through: 65 grams of total fat. 65 g of fat x 9 kcal/g fat = 585 kcal. This means that 585 kcal came from fat for that day. Next, divide the number of calories from fat by the total number of calories consumed for the day. 585/1,800= 0.325. After you multiply this decimal by 100; you find that 32.5% of calories came from fat in Jane’s diet on Monday. 240 grams of carbohydrates. 240 g of carb x 4 kcal/g carb = 960 kcal. This means that 960 kcal came from carbohydrates for that day. Next, divide the number of calories from carbohydrates by the total number of calories consumed for the day. 960/ 1800 = 0.53333. After you multiply this decimal by 100 and round, you find that 53% of calories came from carbohydrates in Jane’s diet on Monday. 55 grams of protein. 55 g of pro x 4 kcal/g pro = 220 kcal. This means that 250 kcal came from protein for that day. Next, divide the number of calories from carbohydrates by the total number of calories consumed for the day. 250/1800 = 0.138889. After you multiply this decimal by 100 and round, you find that 14% of calories came from protein in Jane’s diet on Monday. ** When it looks like students are done with the exercise, continue** Say: Does anyone know the percent of calories that Jane consumed from fat? (Answer= 32.5%). What about the percent of energy from carbohydrates? (Answer= 53%) And, finally—what about the protein? (Answer= 14%). When you add those percents up, the total should be at or very near 100 %.(32.5 + 53.0 + 14 = 99.5). And, for our example, we find that it is! Say: So, did Jane follow the Dietary Guidelines for Americans’ recommendations for fat intake? (Answer = yes, 32.5% falls within the range of 25 to 35%). What does everyone think will happen if Jane continues to eat fewer calories than recommended? (Answer = with time, she will lose weight). We will go over this in more detail in just a little while. And, finally does anyone know which side of the scale corresponds to the 1,800 calories that Jane consumed? (answer = “A”).9 Energy In Say: You might ask, “How do I know how many calories I am consuming each day?” Luckily, there is an easy answer. For most foods that you eat, the food package will show a nutrition facts panel. The nutrition facts panel provides information about calories, fat, carbohydrates, protein and other nutrients contained in the food. You can even find nutrition facts panels on the package of most meat that is purchased (like ground beef, chicken breasts, etc) in the meat section at your local grocery store. The only thing that might be a little hard to find information on is fresh produce, although
some stores are starting to list this information at the produce section. Here is an example of a nutrition facts panel. This example is for a small container of fat-free milk. One important thing that I must point out is the serving size and number of servings per container of package. Understanding how many calories you are actually consuming can be tricky unless you understand this part. In red, we have highlighted the serving size found in this beverage. It is 8 ounces, or 1 cup. Everything listed below this--- calories, total fat, carbohydrates, protein, etc—is pertaining to how much of each nutrient is found in one serving. But, there is not just one serving in this container. If you look at the part highlighted in blue, you will see that there are two servings of milk in the container. Therefore, if you were to drink the entire container, you would be consuming not one but rather two servings, and would have to multiply the calories, along with everything else listed below, by two. From looking at this nutrition facts panel that I have here, Can anyone tell me how many grams of total fat are found in ONE serving of skim milk? (Answer = zero grams) Yes, skim milk contains no fat. Can anyone tell me how many grams of total carbohydrates are found in ONE serving of skim milk? (Answer = 12 grams) What about in TWO servings? (Answer = 24 grams) Can anyone tell me how many grams of protein are found in ONE serving of skim milk? (Answer = 8 grams) What about in TWO? (Answer = 16 grams).10 Energy Output Say: Now we know how to calculate the number of calories (and amounts of fat, carbohydrates, and protein) that we consume from foods. And, as we said earlier this is what contributes to energy input -- the energy that goes into our bodies from the food that we eat! Next, we will talk about the other side of the scale (or seesaw) of energy balance—and that is energy output. Energy output deals with the amount of calories (energy) that you use each day. There are three factors that account for the calories you use each day and these are: Basal metabolism Physical activity (and the) Thermic effect of food Basal metabolism makes up the largest portion of energy output, followed by physical activity and then the Thermic effect of food. I think that of these three terms, we are more likely to be familiar with physical activity—but in just a while, we will be familiar with basal metabolism and Thermic effect of food, too. Let’s start with basal metabolism.11 Energy Out – Basal Metabolism Say: No matter how still your body is, internal activity always continues—even while you are asleep. While resting, your brain and liver, two very important organs, use
about 40% of your body’s energy. Your lungs, another important organ, also have to continue working to supply your tissues with oxygen. Basal metabolism can be defined as the amount of energy required to support the operation of all internal body systems except for digestion. It includes the energy your body uses every day to breathe, circulate blood, and maintain nerve activity. Things like secreting hormones, maintaining body temperature, and making new cells are also part of basal metabolism. The rate at which your body uses energy for basal metabolism is known as your basal metabolic rate (BMR). An equation called the Harris benedict equation is used to calculate energy needs. Harris-Benedict equation gives us our BMR or BEE (basal energy expenditure). Harris Benedict for men, B.E.E. = 66.5 + (13.75 x kg) + (5.003 x cm) - (6.775 x age) Harris Benedict for women, B.E.E. = 655.1 + (9.563 x kg) + (1.850 x cm) - (4.676 x age) Total Caloric Requirements equal the B.E.E. multiplied by the sum of the stress and activity factors. Stress plus activity factors range from 1.2 to over 2. Harris Benedict equation does not account for physical activity. That’s because physical activity is not a portion of your BMR. It is a separate concept.12 Basal metabolic rate Say: So, if the BMR is the largest slice from the pie of energy output, then what predicts our BMR? There are actually many factors which effect BMR, some of which include: your body structure (height), body composition, and gender. Body structure A tall person will have a higher BMR than a short person because the tall person has more body surface area through which heat is lost. Body composition refers to the percent of different tissues in the body, like: fat, muscle and bone. Someone with a high proportion of muscle will have a higher BMR than someone with more fat tissue. This is because it takes more calories to maintain muscle tissue than it does for fat. This means that muscle is more metabolically active. Gender Males will generally have a higher BMR than females since males have more lean body mass than do females. Age is another factor. As you grow older, your BMR tends to decline. There is actually a 5% decrease in BMR for every 10 years past the age of 30.13 Basal metabolic rate Say: There are other factors which influence BMR. These include: body temperature, thyroid gland secretion, diet type, and periods of growth. Body temperature is one factor. Temperature, both inside and outside of the body, can adjust your BMR. For example, fever increases BMR.
Thyroid gland secretion is another factor. The thyroid gland secretes a hormone known as thyroxine, which regulates basal metabolism. In some instances, people have an overactive thyroid gland, which secretes too much thyroxine, in which case—these people have a high BMR. The opposite can also be true. Some people have an underactive thyroid gland, in which case not enough thyroxine is released causing a lower BMR. Diet. The calorie content of your diet can also influence your BMR. A diet that is very low in calories actually decreases your BMR by about 10 to 20%. This is because your body views this as a period of famine and tries its best to effectively operate on what is available. In simple terms, the body lowers its energy need to try its best to still do the essential functions. This is why someone restricting calories only (and not exercising) may have a hard time reaching weight goals. Exercise is an important part of any weight loss goal. Finally, periods of growth can also change the BMR. During growth, BMR are higher. This is true during infancy, childhood, and teen years, when the body is growing and expanding—and also during pregnancy. As you probably noticed, there aren’t many factors that we’ve discussed that you can change. However, there is one way that you may be able to impact your BMR; and that is, by adding regular physical activity into your lifestyle. This can help you develop more muscle and as we said, higher muscle mass means a higher BMR.14 Physical activity Say: The second category of energy output is the energy you use for physical activity. The amount of energy that you burn during an exercise depends on: your body size and the actual movement of your muscles. The larger the body size, the more energy you will need in order to make the muscles work. With that said, we would expect a 220- pound woman to burn more calories while walking than a 150-pound woman walking at the same pace. The amount of muscle movement that you do during exercise also influences how many calories you will burn. Swinging your arms while you walk will cause you to burn more calories than if you walked keeping your arms at your sides. Someone who fidgets while sitting at a desk spends more energy than someone who sits still.15 Energy cost of various physical activities Say: On this slide, you will see the energy costs for various activities. Activities are separated based on intensity, where the top represents those that burn the least number of calories and the bottom represents the most strenuous of all activities. Like I had mentioned earlier, you are always using calories. Even when you sleep. Who would have thought that for every hour that you sleep, you burn 60 calories. Of course you would have to do more physical activity than just sitting and sleeping, or else you would not have a very large energy output. Be sure to note that the calories used column represents how many calories are used per hour of engaging in a particular activity. So, if you only did an activity for 15 minutes (or ¼ of an hour), then you would have to divide the number that you look up on the chart for that activity by 4.
Do: Read over each type of activity and state examples of each.Activity Calories used per hourSleep 60Sedentary activities 80 to 100Such as reading, eating, watching television, sewing, (average = 90)playing cards, using a computer, studying, othersitting activities.Light activities 110 to 160Such as cooking, doing the dishes, ironing, grooming, (average = 135)walking slowly, more strenuous sitting activitiesModerate activities 170 to 240Such as walking moderately fast, making beds, light (average = 205)gardening, standing activities requiring armmovementVigorous activities 250 to 350Such as walking fast, bowling, golfing, yard work (average = 300)Strenuous activities 350 or moreSuch as running, dancing, bicycling, playing football,playing tennis, cheerleading, swimming, skiing,playing active gamesSay: Next, I will hand out an assignment so we can put what we have learned aboutphysical activity to the test. It will be a list of all activities that were done over a 24-hour period by a person. All that you have to do is figure up: The total time spend doing each activity, Decide which type of activity it is (light, moderate, etc) and then Determine how many calories that exercise used for that given amount of time.Be sure to use the average amount of calories used per hour when it is listed, too.Do: Pass out the Physical activity handout.Say: I want everyone to learn how to do this on their own, but feel free to get help froma friend if you are stuck. You can also ask me for help if you have any questions.---------------------------------------------BREAK--------------------------------------------------Do: Allow students time to work through the assignment. Walk around the room andassist any student who is stuck. When it looks like the students are done, proceed.Say: Can anyone tell me which one of Alyssa’s activities burned the greatest # ofcalories? (Answer = cheerleading)
Which activity burned the least number of calories? (Answer = riding in the car) What was the total number of calories that she burned for the day? (Answer = ~3,049 kcal)16 Thermic effect of food Say: Your third need for energy is due to the Thermic effect of food. The Thermic effect of food is the energy required to complete the processes of digestion, absorption, and metabolism. It can be thought of as the energy required to extract energy from food. Although it can differ slightly depending on the types and amounts of foods eaten, the Thermic effect of food is generally equal to only 5 to 10% of your combined basal metabolism and physical activity needs. So, if a person burned 2,200 calories for physical activity and basal metabolism, then they would spend about 220 calories for the Thermic effect of food (2200 x 0.10 [10 percent] = 220)17 How does energy balance work? Say: In the next section, we will talk about energy balance and imbalance—what would lead to either one of these situations.18 So, energy balance looks like… Say: Are you in energy balance? Well, you could figure this out by calculating your energy input – the number of calories that you consume on a given day and comparing this with your energy output—from physical activity, basal metabolism and the Thermic effect of food. The less complicated way is to follow your weight over time. If you are gaining or losing weight, then you will know that you are not. If your weight remains relatively stable from week to week, and month to month, then you are. Your energy input would be relatively equal to your energy output. Of course, everyone’s weight fluctuates from time to time, but if you see your weight headed in a certain direction—either steadily up or steadily down, you will know that you are not in balance. There are two causes of energy imbalance and that is: consuming too many or too few calories. Consuming too many calories is referred to as energy excess, whereas consuming too few is referred to as energy deficiency. In the U.S. are we usually more likely to consume too many or not enough calories considering that 2/3rd of the population is overweight or obese? (Let students think and attempt to answer).Too many.19 Am I in energy balance? Say: The following is important to understand. The first equation in pink explains what contributes to weight gain, and that is – as you may have guessed, an energy input that is greater than your output. So, what does that mean? That means that you are consuming more calories than what you actually need. A seesaw of this example with energy input on one side and energy output on the other would have energy input
weighing down one side. You’re consuming more calories than what your body needs and you will put on weight. The second equation in blue explains what contributes to weight loss, and that is—an energy input that is less than your output. So, what does that mean? That means that you are not consuming enough calories to meet your energy needs. A seesaw of this example with energy input on one side and energy output on the other side would have energy input elevated much higher than energy output. You’re not consuming enough calories to meet your needs and you would lose weight. Finally, the last equation in orange explains what contributes to weight maintenance and that is—and energy input that is equal to your output. So, what does that mean? That means that what you are consuming is matching what you are using. Weight maintenance is important because if you are already at a healthy weight, then you don’t want to lose or gain any extra weight.20 Basal metabolic calculator Say: There are ways of calculating basal metabolic rate without being measured by a respirometer. One of the ways is to use a standardized equation. There are many equations around to do this and they are all fairly accurate to give us an idea of our energy needs. We will use these equations for men and women to calculate resting metabolic rate. This is your modified Harris Benedict equation using pounds and inches instead of meters and kilograms.21 Let’s calculate BMR Say: As an example, we will use Sue who is 18 yrs, 5’ 4”, 145 lbs. I will show you the calculation using her information.22 Harris Benedict Formula Say: To determine your total daily calorie needs, multiply your BMR by the appropriate activity factor, as follows: If you are sedentary (little or no exercise, mainly sitting, watching TV, reading) : Calories = BMR x 1.2 If you are lightly active (light exercise/sports 1-3 days/week) : Calories = BMR x 1.375 If you are moderately active (moderate exercise/sports 3-5 days/week): Calories = BMR x 1.55 If you are very active (hard exercise/sports 6-7 days a week) : Calories = BMR x 1.725 If you are extra active (very hard exercise/sports & physical job) : Calories = BMR x 1.9
23 Let’s calculate energy expenditure Say: Once we have basal metabolic rate, we can also calculate total energy expenditure on an individual once we know how many hours of a type of activity they engage in. In our example, Sue has the following activity pattern: Sleep = 9 hrs, Light activity = 6 hrs, Sitting in class = 5 hrs, Homework = 2 hrs, Walking = 2 hrs. Total = 24 hours We can now plug our information in the equation and find our total energy expenditure. For Sue: Sue EE = (9/24 x BMR) + (6/24 x BMR x 1.375) + ( 7/24 x BMR x 1.25) + (2/24 x BMR x 1.55) = (9/24 x 1512) + (6/24 x 1512 x 1.375) + (7/24 x 1512 x 1.25) + (2/24 x 1512 x 1.55) = 567 + 519.75 + 551.25 + 195.30 = 1833.3 ~ 183324 The truth about physical activity Say: As I just mentioned, Americans are not exercising as much as they should be. And, physical activity is a big piece to the puzzle of energy balance. Even if you aren’t trying to lose weight, it is very important not only because of the benefits that it provides, but also because it increases your energy output, allowing you to consume more calories each day (energy input) without gaining weight. And, if you are trying to lose weight, combining dietary efforts (lower calorie food choices) with exercises greatly improves the odds that you will be successful. From a survey taken in 2001 in the United States, we see that only 4 out of 10 women are engaging in the recommended levels of physical activity. Physical activity has been shown to be influenced by age (where activity is shown to decline with age), gender (where males are more likely to exercise than are females), income status and education levels, where those with less education and income are less likely to exercise than those with higher income status and education levels.25 The benefits of exercise Say: So, what are the benefits of exercise? There are many. One benefit is that exercise helps to strengthen your cardiovascular and respiratory systems. You may not understand why this is a huge benefit now, but know that cardiovascular disease is not something that just occurs over night—it is a gradual process that begins even in childhood. Doing things that are good for your heart now will definitely pay off later in life. Another benefit is that exercise helps to keep your bones and muscles strong. Regular exercise is one of the best things that you can do to keep yourself from getting
the bone-weakening disease later in life, known as osteoporosis. Also, strong bones and muscles help you to have better balance and coordination. As we’ve already touched on, regular exercise also helps to manage your weight since it increases the calories that your body uses, better matching calories in with calories out. Maintaining a healthy weight is essential to prevent obesity and to prevent conditions such as arthritis later in life caused by extra weight on bones and joints. Exercise also helps you to prevent the development of diabetes or manage the condition if you already have it. For people with type 2 diabetes, a healthy diet combined with regular physical activity is essential to control their condition. Reoccurring elevated sugar levels in the blood from foods high in carbohydrate (high glycemic-foods) in people who are sedentary greatly puts you at risk for the development of Type 2 diabetes. Exercise is good not only for people who already have the condition, but also for people without the condition as it helps to lower their risks. Exercise lowers blood sugar levels in two ways. One is by pulling sugar from the blood to the muscles to use for energy both during and after exercise. The other is by helping to increase insulin’s sensitivity (ability to do its job). Insulin is the hormone responsible for regulating blood sugar. When it is working properly, it pulls blood sugar from the blood and into the cells where it can be used for energy. Exercise also helps to ease depression and manage pain and stress. It does so by activating neurotransmitters, which are chemicals used by nerve cells to communicate with one another. The activation of these neurotransmitters is associated with avoidance of depression. Exercise also activates endorphins, which are other neurotransmitters that produce feelings of “well-being” for natural pain and stress relief Exercise also helps to lower your risk for developing certain cancers. These cancers are: prostate, colon, uterine lining (endometrium) and breast. Exercise is believed to lower the risk of breast and endometrial cancer by reducing body fat and lowering the production of estrogen. Researchers are not quite as sure of how exercise helps to lower colon cancer, but they believe that it may have something to do with the fact that exercise helps digested food to move through the colon more quickly. How exercise helps to lower the risk for prostate cancer in men is at present, unknown. And, finally exercise can help you sleep better. Moderate physical activity at least 3 hours before bedtime has been shown to help you relax and sleep better at night.26 Inactivity Say: Exercise has many excellent benefits. But in order to receive these benefits, you must exercise. Physical inactivity leads to loss of muscle, reduced functional capacity, and can contribute to obesity over time. Exercise helps to protect us against the development of heart disease, diabetes and certain kinds of cancer, so if you don’t exercise—then you are at greater risk for these diseases. It is true that individuals who are fit can do more things, have better endurance for activities and tasks, and are healthier than individuals of low fitness. You have to be a “star athlete” however.
Regular physical activity of any sort has benefits. So, whether you are increasing your activity each day by walking a little more, doing some cleaning, or challenging your friends to a basketball game, remember that a little change goes a long way. Start out slow and gradually and build more exercise into your daily activities. And, don’t stress if you fall out of your routine on one day. Start out fresh again the next day.27 Energy imbalance Say: Consuming more calories than you need will lead to weight gain over time. This is why exercise is so important. It increases your energy output and promotes energy balance. Exercise is the one component of energy output that you have the most control over. Did you know that for every 3,500 calories you have in excess of needs, one pound of body weight is gained? This seems like a large number, but it can creep up on you quicker than you might realize at times because this is a cumulative process that builds up over days, weeks, months and even years. Eating an extra 280 calories each day, say from a candy bar, could lead to 1 lb of stored body fat in less than 2 weeks. In one year, if you were to eat an extra 280 calories each day and not adjust for it by increasing your activity, you could gain as much as 27 pounds! Obesity is becoming more prevalent. Increasing portion sizes are believed to have contributed to weight gain in recent years, as people are consuming much more calories this way--- and are not always aware of it. An example would be choosing a larger version of fries or a soft drink at a fast food restaurant. For example, a small order of fries has 230 calories; whereas the largest order of fries has 600 calories. This is a difference of 370 kcals! The same is true with beverages. A small coke from a fast food restaurant may only have 140 calories, but if you were to order a king size coke, you would be consuming 390 calories from a beverage. The difference between the small and king size drink is 250 kcals! An over reliance on convenience foods in recent years has also believed to contribute to obesity as the options chosen by most people are generally high in calories and fat. Americans, as a whole, are also much less active than they used to be. And, these sedentary behaviors, alone or combined with higher energy intakes, are believed to have contributed to much of the weight gain that we have seen in recent years. So, how do we overcome this? One big part is choosing better food choices. The Dietary guidelines for Americans tell us to choose a variety of nutrient-dense foods each day, and to limit those foods dense in energy with little to no nutrient value.28 Recommendations for physical activity Say: Another big part is increasing physical activity. It’s hard to change our eating habits—these are something that we’ve learned from birth. Incorporating regular physical activity into your daily activities is another good option. And, remember no one expects you to completely change your lifestyle over night. It’s the drastic changes in our lifestyle that are the hardest to keep. It’s the small changes that we are able to live with and even small changes can add up in a big way over time. Be sure to remember that the Dietary Guidelines for Americans recommend that all
children and adolescents should engage in at least 60 minutes of physical activity on most, but preferably all, days of the week.29-34 Review Say: The statement on each of the slides in navy blue—asking students if they feel that the statement is true or false. Do: Encourage students to answer and ask them to say why they feel it is true or why they feel it is false (depending on their answer). Once you have received enough answers to proceed, press the space bar to reveal the answer, along with the explanation of why it is the right answer.35 Maintain the balance36 Authors: Heli Roy, PhD, RD Shanna Lundy, MS Division of Education Phillip Brantley, PhD, Director Pennington Biomedical Research Center Steven Heymsfield, MD, Executive Director The Pennington Biomedical Research Center is a world-renowned nutrition research center. Mission: To promote healthier lives through research and education in nutrition and preventive medicine. The Pennington Center has several research areas, including: Clinical Obesity Research Experimental Obesity Functional Foods Health and Performance Enhancement Nutrition and Chronic Diseases Nutrition and the Brain Dementia, Alzheimer’s and healthy aging Diet, exercise, weight loss and weight loss maintenance The research fostered in these areas can have a profound impact on healthy living and on the prevention of common chronic diseases, such as heart disease, cancer, diabetes, hypertension and osteoporosis. The Division of Education provides education and information to the scientific community and the public about research findings, training programs and research areas, and coordinates educational events for the public on various health issues.
We invite people of all ages and backgrounds to participate in the exciting researchstudies being conducted at the Pennington Center in Baton Rouge, Louisiana. If youwould like to take part, visit the clinical trials web page at www.pbrc.edu or call (225)763-3000.Edited: October 2012