Lecture Presentation Outline
I.
Calories
 Instructor Resources: Unit 8 Nutrition Scoreboard transparency master; Unit 8 PowerPoint presentation
on Multimedia Manager
A. A calorie is a unit of measure of energy
 Instructor Resources: transparency #26: Calories: A Unit of Measure
1. A calorie is the energy needed to raise one kilogram of water from 15°C to 16°C (59°F to 61°F)
2. This is the standard for caloric values of foods
3. Calories are a unit of measure are not a component of food
4. Calorie content of a food is the food’s energy content
B. Caloric value of food can determined by Calorimetry
 Instructor Resources: transparency #28: Measuring Energy Content of Foods
1.
2.
3.
4.
Calorimetry burns food in a container surrounded by water
Energy released raises the temperature of the water
Rise in temperature reveals amount of calories released
Heat from burning equals energy obtained by the body
II. Body Needs Energy
A. Body uses energy:
1. To fuel muscular activity
2. For growth
3. For tissue repair and maintenance
4. To chemically process nutrients
5. To maintain body temperature
B. Body needs for energy in three categories:
 Instructor Resources: transparency #27: Energy-Requiring Processes
1. Basal metabolism
2. Physical activity
3. Dietary thermogenesis
C. Basal metabolism uses 60-80% of total calories for:
1. Breathing
2. Beating of the heart
3. Maintenance of body temperature
4. Renewal of muscle and bone tissue
5. Ongoing activities to sustain life and health
6. Growth is component of basal metabolism
a. Calories for basal metabolism highest during growing years
7.
Basal metabolic processes require no conscious effort
a. Continuous activities the body performs to sustain life
b. Energy needed for basal metabolism is measured when body is in complete physical and
emotional rest
III. How Much Energy?
A. Estimate calories for basal metabolism by quick formula:
1. For men: Multiply body weight in pounds by 11
2. For women: Multiply body weight in pounds by 10.1
3. A man of 170 pounds needs 170 x 11, or 1870 calories per day
4. A 135-pound woman needs 135 x 10, or 1350 calories
5. Formula estimates basal metabolism for gender and weight
6. Other factors affect how efficiently the body uses calories
a. Physical activity level
b. Muscle mass, height
c. Health status
d. Genetic traits
7. Results from quick formula may be 10 to 20% lower or higher than the true number required
for basal metabolism
B. Physical Activity?
 Instructor Resources: Activity 9 in Instructor’s Activity Book: Physical Activity Assessment
1.
2.
Calories needed for physical activity vary according to how active you are
Usually second highest calories expended
a. Energy cost of inactive lifestyle 30% of calories for basal metabolism
b. “Average” activity level requires roughly 50%
c. “Active” level requires approximately 75%
3. Example: Inactive person needing 1500 calories for basal metabolism would require about
450 calories for physical activity
4. Common Error
a. People overestimate time in physical activity
b. Overestimated calorie need for physical activity leads to inaccurate estimate of total
calorie need
c. Physical activity level based only on time in physical activity
1. Does not include time spent getting ready for the activity, on breaks, or between
activities
C. Calories for Thermogenesis
1. Some energy expenditure is for chewing and swallowing foods, digesting foods, absorbing
and utilizing nutrients, and transporting nutrients into cells
2. Some energy involved in these activities escapes as heat
3. Processes are dietary thermogenesis
4. Calories for dietary thermogenesis are about 10% of sum of basal metabolic and physical
activity calories
a. Example: basal metabolic needs 1500 calories
physical activity needs 450 calories
1500 + 450 calories = 1950 calories
calories for dietary thermogenesis equal approximately 10% of 1950 calories, or 195
calories
D. Adding It All Up
 Instructor Resources: Activity 8-2: Caloric Expenditure
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2.
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Estimated total daily need for calories is sum of calories used for basal metabolism, physical
activity, and dietary thermogenesis
In the example, total calorie need is 2145 (1500 + 450 + 195) calories
Caloric level estimated this way is not exactly right, but should be close to total caloric need
IV. Energy in Foods?
A. Foods that contain carbohydrates, proteins, or fats supply body with energy
 Activity 8-5: Endless Energy
1. Carbohydrates supply 4 calories/gm
2. Proteins supply 4 calories/gm
3. Fat provides 9 calories/gm
B. Alcohol is a source of energy
1. Alcohol provides 7 calories/gm
C. Calorie Calculations
 Instructor Resources: Activity 8-4: Sources of Calories in Bread; Activity 8-6: Breakfast Cereal Nutrition
Information; Handout 8-2: Breakfast Cereal Nutrition Information
1.
If you know carbohydrate, protein, fat, and alcohol content of food you can calculate the
calories it contains
a. Soup contains 15 gm carbohydrate, 10 gm protein, and 5 gm fat
b. Calculate the calories in the soup. Multiply gm of carbohydrate and protein by 4 and gm
of fat by 9, and add results
15 grams carbohydrate x 4 calories/gram
= 60 calories
10 grams protein x 4 calories/gram
= 40 calories
5 grams fat x 9 calories/gram
= 45 calories
Total = 145 calories
c. Calculate percentage of total calories from carbohydrate, protein, and fat by dividing
number of calories supplied by each nutrient by total calories and multiplying by 100
Carbohydrate [60 calories]/[145 calories] = 0.41x100 = 41%
Protein
[40 calories]/[145 calories] = 0.28x100 = 28%
Fat
[45 calories]/[145 calories] = 0.31x100 = 31%
D. Foods Are Mixtures
 Instructor Resources: Activity 8-1: Food Composition; Activity 8-3: Spaghetti Sauce Recipe Calculation;
Handout 8-1: Spaghetti Sauce Activity
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2.
Some foods composed of just one energy nutrient
Most foods contain many substances in varying amounts
a.
b.
Bread is high in carbohydrates, and contains protein, water, vitamins, minerals, and fiber
Lean sirloin steak is 32% protein, 8% fat and 60% water
V. Caloric Intake Regulated?
A. Body mechanisms encourage regular calorie intake
B. Mechanisms are independent of weight
1. Encourage eating to sustain body in hard times
2. Store fat to get through scarcity (advantageous)
3. Thin or fat, people get hungry through the day
C. Hungry signal when cells run low on energy
D. When we eat, we should lose interest in eating
1. Signal from brain, stomach, liver, fat cells indicate satiety, feeling that we’ve had enough to
eat
E. Appetite
 Instructor Resources: Activity 6 in Instructor’s Activity Book: Does the Amount of Food Available
Influence How Much We Eat?
1.
2.
3.
Hunger and satiety mechanisms adjust intake
Internal signals can be overridden
a. People resist eating in spite of hunger pains
b. People can go on eating after the “Full” signal
People may eat due to appetite
a. Appetite is urge for pleasure of eating
b. Appetite may or may not be related to hunger
c. Appetite triggered by smell or sight of food
VI. Energy Balance
 Instructor Resources: CNN Today Nutrition Vol. 2: Freshman 15 (2:00)
A. Calories you need are the number you consume
1. Adults maintaining weight are in energy balance
2. Unchanged weight means body’s expenditure and intake of energy are balanced
B. Energy intake less than expended is negative energy balance
1. Here energy stores are used, people lose weight
C. Energy intake more than expended is positive energy balance
1. Here fat stores are gained, more energy available than needed
2. Positive energy balance is normal in growth, or regaining weight lost during an illness
D. Total caloric need to maintain energy balance and weight is affected by:
1. Smoking
2. Lean muscle mass
3. Genetic makeup
E. People who smoke use more calories, and muscular individuals need more energy to maintain
body weight
F. Small changes best!
1. Genes may increase or decrease calorie need
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Small changes in calorie need may not mean much on a day-to-day basis
But, over a year a consistent positive or negative daily energy balance of 50 calories could
result in a weight gain or loss of five pounds
“Calories” doesn’t mean “fattening” or “bad for you.”
a. Calories are life- and health-sustaining
b. Diets compatible with health contain foods providing various amounts of calories