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Energy Balance
Chapter 7
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Energy Intake
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Calories come from carbohydrates, protein, fat, and alcohol
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The total number of calories in a food or diet can be estimated by multiplying total grams of
carbohydrates, protein, or fat by the appropriate number of calories/gram
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Even when all food consumed is measured, the nutrient values available in food composition
references represent average, not actual, nutrition content
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Energy Intake (cont’d)
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Easier way to count calorie intake is to estimate the number of servings from each food group a
person consumes; multiply the number of servings by the average amount of calories in a
serving; then add the calories from each group to get an approximation of the total calories
consumed
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Accuracy of “counting servings” depends on the quality of foods consumed and the accuracy of
portion size estimation
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Energy Expenditure
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Basal metabolism
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Caloric cost of staying alive or the amount of calories required to fuel the involuntary
activities of the body at rest after a 12-hour fast
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Basal metabolic rate (BMR) accounts for approximately 60% of total calories expended
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The less active a person is, the greater the proportion of calories used for basal
energy expenditure (BEE)
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Energy Expenditure (cont’d)
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Basal metabolism (cont’d)
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Rule-of-thumb guideline for estimating BMR is to multiply healthy weight (in pounds) by
10 for women and 11 for men
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When actual weight exceeds healthy weight, an “adjusted” weight of halfway between
healthy and actual can be used
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Rule of thumb based on weight only
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Energy Expenditure (cont’d)
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Basal metabolism (cont’d)
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Lean tissue (muscle mass) contributes to a higher metabolic rate than fat tissue
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Loss of lean tissue that usually occurs with aging beginning sometime around age 30 is
one reason why calorie requirements decrease as people get older
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Energy Expenditure (cont’d)
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Physical activity
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Accounts for approximately 30% of total calories used
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Rule-of-thumb method for estimating daily calories expended on physical activity is to
calculate the percent increase above BMR based on the estimated intensity of usual
daily activities
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Energy Expenditure (cont’d)
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Estimating total calorie requirements
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Estimated energy requirements (or EER) based on age, weight, height, and physical
activity (PA), with defined PA factors for men and women based on intensity of activity
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Quicker and easier reference is the MyPyramid calorie level table based on gender, age,
and activity
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Calories in Versus Calories Out
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State of energy balance is the relationship between the amount of calories consumed and the
amount of calories expended
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A “positive” energy balance occurs when calorie intake exceeds calorie output
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A “negative” calorie balance occurs when calorie output exceeds intake
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Question
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Is the following statement true or false?
A man with an actual weight of 210 pounds and a “healthy” weight of 175 pounds has a basal
metabolic rate of 2,220.
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False.
Answer
Rationale: When actual weight exceeds healthy weight, an “adjusted” weight of halfway
between healthy and actual can be used:
210 – 175 = 35
35/2 = 17.5
175 + 17.5 = 192.5
192.5 x 11 = 2117.5 BMR
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What Is “Normal” Weight
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“Normal” or “desirable” weight is that which is statistically correlated to good health
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3 criteria used for assessing overweight and obesity:
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Body mass index (BMI)
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Waist circumference
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Existing health problems
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What Is “Normal” Weight (cont’d)
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Body mass index
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Body mass index (BMI) has replaced traditional weight–height calculations that were
used to determine “ideal” or “desirable” body weight
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Formula to calculate BMI is weight in kg/height in meters squared or weight in
pounds/height in inches squared x 703
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Drawback
o
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Does not take body composition into account
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Skinfold measurements and bioelectrical impedance can assess body composition, but
neither technique is widely used
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What Is “Normal” Weight (cont’d)
Waist circumference
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Location of excess body fat may be a more important and reliable indicator of disease
risk
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Storing a disproportionate amount of total body fat in the abdomen increases risks for
type 2 diabetes, dyslipidemia, hypertension, and cardiovascular disease
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Abdominal fat is clinically defined as a waist circumference ≥40 inches in men and ≥35
inches in women
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What Is “Normal” Weight (cont’d)
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Existing health problems
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Presence of existing health problems impacts a person’s absolute risk related to weight
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Generally, the number and severity of comorbid conditions increases with increasing
levels of obesity
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Energy Balance in Health Promotion
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Approximately 66% of the adult American population is overweight or obese
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Preventing or reducing overweight is achieved by adopting a lifestyle approach that includes
healthier food choices, increasing physical activity, and behavior modification
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Energy Balance in Health Promotion (cont’d)
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Healthier choices
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Encompasses a 2-pronged approach
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Eating less of certain items
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Eating more of others
Emphasis is on healthy and wholesome choices
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Remember fat-free foods still contain calories from protein and carbohydrates
Reducing alcohol intake is another way to consume fewer calories
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Energy Balance in Health Promotion (cont’d)
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Portion control
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Portion sizes have grown over the last 20 years
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“Portion distortion” appears to be a widespread problem
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Change the environment
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Food should be less accessible, less visible, and proportioned in smaller
quantities
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Energy Balance in Health Promotion (cont’d)
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Physical activity
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Only 30% of American adults engage in regular leisure-time physical activity; 39% of
adults do not engage in any leisure-time physical activity
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Benefits of increasing activity are dose-dependent and occur along a continuum
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Minimum of 30 minutes/day of moderate-intensity activity above usual activity is
recommended
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Other types of exercise are also recommended
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Question
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There are 3 criteria used for assessing overweight and obesity. What is one of these criteria?
a. Height
b. Healthy weight
c. Existing health problems
d. Basal metabolic rate
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Answer
c. Existing health problems
Rationale: 3 criteria used for assessing overweight and obesity include:
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Body mass index (BMI)
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Waist circumference
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Existing health problems
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How to Burn 150 Calories
(Based on a 150-Pound Person)
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Pedal a stationary bicycle for 20 minutes
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Practice fast dance steps for 24 minutes
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Work in the garden for 27 minutes
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Walk briskly (3.5 mph) for 33 minutes
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Clean the house for 38 minutes
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Suggestions for Increasing Activity
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Find something enjoyable
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Use the buddy system
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Spread activity over the entire day if desired
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Start slowly and gradually increase activity
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Move more
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Keep an activity log