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Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins
Energy Balance
Chapter 7
Energy Balance
Chapter 7
Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins
Energy IntakeEnergy Intake• Calories come from carbohydrates, protein, fat,
and alcohol
• 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
• Even when all food consumed is measured, the nutrient values available in food composition references represent average, not actual, nutrition content
Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins
Energy Intake (cont’d)Energy Intake (cont’d)• 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
• Accuracy of “counting servings” depends on the quality of foods consumed and the accuracy of portion size estimation
Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins
Energy ExpenditureEnergy Expenditure
• Basal metabolism
– 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
– Basal metabolic rate (BMR) accounts for approximately 60% of total calories expended
o The less active a person is, the greater the proportion of calories used for basal energy expenditure (BEE)
Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins
Energy Expenditure (cont’d)Energy Expenditure (cont’d)
• Basal metabolism (cont’d)
– Rule-of-thumb guideline for estimating BMR is to multiply healthy weight (in pounds) by 10 for women and 11 for men
– When actual weight exceeds healthy weight, an “adjusted” weight of halfway between healthy and actual can be used
– Rule of thumb based on weight only
Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins
Energy Expenditure (cont’d)Energy Expenditure (cont’d)
• Basal metabolism (cont’d)
– Lean tissue (muscle mass) contributes to a higher metabolic rate than fat tissue
– 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
Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins
Energy Expenditure (cont’d)Energy Expenditure (cont’d)
• Physical activity
– Accounts for approximately 30% of total calories used
– 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
Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins
Energy Expenditure (cont’d)Energy Expenditure (cont’d)
• Estimating total calorie requirements
– 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
– Quicker and easier reference is the MyPyramid calorie level table based on gender, age, and activity
Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins
Calories in Versus Calories Out Calories in Versus Calories Out
• State of energy balance is the relationship between the amount of calories consumed and the amount of calories expended
• A “positive” energy balance occurs when calorie intake exceeds calorie output
• A “negative” calorie balance occurs when calorie output exceeds intake
Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins
QuestionQuestion
• 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.
Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins
AnswerAnswerFalse.
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
Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins
What Is “Normal” WeightWhat Is “Normal” Weight
• “Normal” or “desirable” weight is that which is statistically correlated to good health
• 3 criteria used for assessing overweight and obesity:
– Body mass index (BMI)
– Waist circumference
– Existing health problems
Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins
What Is “Normal” Weight (cont’d)What Is “Normal” Weight (cont’d)
• Body mass index
– Body mass index (BMI) has replaced traditional weight–height calculations that were used to determine “ideal” or “desirable” body weight
– Formula to calculate BMI is weight in kg/height in meters squared or weight in pounds/height in inches squared x 703
– Drawback
o Does not take body composition into account
– Skinfold measurements and bioelectrical impedance can assess body composition, but neither technique is widely used
Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins
What Is “Normal” Weight (cont’d)What Is “Normal” Weight (cont’d)
• Waist circumference
– Location of excess body fat may be a more important and reliable indicator of disease risk
– Storing a disproportionate amount of total body fat in the abdomen increases risks for type 2 diabetes, dyslipidemia, hypertension, and cardiovascular disease
– Abdominal fat is clinically defined as a waist circumference ≥40 inches in men and ≥35 inches in women
Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins
What Is “Normal” Weight (cont’d)What Is “Normal” Weight (cont’d)
• Existing health problems
– Presence of existing health problems impacts a person’s absolute risk related to weight
– Generally, the number and severity of comorbid conditions increases with increasing levels of obesity
Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins
Energy Balance in Health PromotionEnergy Balance in Health Promotion
• Approximately 66% of the adult American population is overweight or obese
• Preventing or reducing overweight is achieved by adopting a lifestyle approach that includes healthier food choices, increasing physical activity, and behavior modification
Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins
Energy Balance in Health Promotion (cont’d)
Energy Balance in Health Promotion (cont’d)
• Healthier choices
– Encompasses a 2-pronged approach
o Eating less of certain items
o Eating more of others
– Emphasis is on healthy and wholesome choices
o Remember fat-free foods still contain calories from protein and carbohydrates
– Reducing alcohol intake is another way to consume fewer calories
Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins
Energy Balance in Health Promotion (cont’d)
Energy Balance in Health Promotion (cont’d)
• Portion control
– Portion sizes have grown over the last 20 years
– “Portion distortion” appears to be a widespread problem
– Change the environment
o Food should be less accessible, less visible, and proportioned in smaller quantities
Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins
Energy Balance in Health Promotion (cont’d)
Energy Balance in Health Promotion (cont’d)
• Physical activity
– Only 30% of American adults engage in regular leisure-time physical activity; 39% of adults do not engage in any leisure-time physical activity
– Benefits of increasing activity are dose-dependent and occur along a continuum
– Minimum of 30 minutes/day of moderate-intensity activity above usual activity is recommended
– Other types of exercise are also recommended
Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins
QuestionQuestion
• 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
Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins
AnswerAnswer
c. Existing health problems
Rationale: 3 criteria used for assessing overweight and obesity include:
– Body mass index (BMI)
– Waist circumference
– Existing health problems
Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins
How to Burn 150 Calories (Based on a 150-Pound Person)
How to Burn 150 Calories (Based on a 150-Pound Person)
• Pedal a stationary bicycle for 20 minutes
• Practice fast dance steps for 24 minutes
• Work in the garden for 27 minutes
• Walk briskly (3.5 mph) for 33 minutes
• Clean the house for 38 minutes
Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins
Suggestions for Increasing ActivitySuggestions for Increasing Activity
• Find something enjoyable
• Use the buddy system
• Spread activity over the entire day if desired
• Start slowly and gradually increase activity
• Move more
• Keep an activity log