Energy Balance and
Weight Control
Dr. David L. Gee
FCSN 245-Basic Nutrition
Energy Balance
 EB
= E(in) - E(out)
E(in)
= dietary intake of energy
E(out) = energy expenditure
Energy Balance:
The Key to Weight Change

When E(in) < E(out)
 Negative
energy balance
 weight loss

When E(in) > E(out)
 Positive
energy balance
 weight gain

When E(in) = E(out)
 Zero
energy balance
 no weight change
How do you measure:
Energy (in)
 Calories
=
energy
required to heat 1 kg
water by 1 degree C.
 Bomb
Calorimeter
©2001 Brooks/Cole, a division of Thomson Learning, Inc. Thomson Learning ™ is a trademark used herein under license.
How do you measure:
E(out)
 Direct
Calorimetry
measures
heat directly
bomb calorimeter (for food)
room calorimeter
 Indirect
Calorimetry
measures
oxygen consumed or
carbon dioxide produced
The effects of energy imbalance
are cumulative!!

If: +EB of 100 Cal/day
 Eat



an additional cookie/day
= +EB of 36,500 Cal/year
If 1 lb fat = 3500 Cal
Then see wt gain of 10 lbs per year !!!
 36,500Cal/year

/ 3500 Cal/lb fat
Therefore, knowing what affects energy balance is
important
 Small
consistent daily changes can accumulate to cause
large weight changes
Energy Out
 Components
of E(out):
Basal
Metabolic Rate (BMR)
Activity (Act)
Thermic Effect of Food (TEF)
 E(out)
= BMR + Act + TEF
Basal Metabolic Rate
 Energy
essential for life support
Circulation
Respiration
Temperature
Maintenance
Nerve Transmission
Kidney Function, etc
Basal Metabolic Rate
 Estimation
of BMR:
 BMR = 0.9 - 1 Cal / kg BW / hr
 Example:
120
lbs / 2.2 lbs/kg = 55 kg
BMR = 55 x 1 x 24hr/d
BMR = 1320 Cal / day
Basal Metabolic Rate
 Factors
affecting BMR
 Age
 BMR
declines 2% per decade
 Height
 BMR
related to body surface area
 Growth
 BMR
highest during periods of growth
 Body
 Lean
Composition
tissue has higher metabolic rate than fat tissue
Basal Metabolic Rate
 Factors
affecting BMR
 Fever
 Increases
by 7% per degree F.
 Stress
 Increases
with physical stress (disease/trauma)
 Undernutrition
 Decreases
with low calorie intake
Energy for Activity
Sedentary (adds 25-35% of BMR)
 Light (35-50%)
 Moderate (50-70%)
 Heavy (>70%)
 Example:

 Light Activity
= 40% x 1320 = 530 Cal
 Moderate Activity = 60%x1320= 790 Cal
 Sedentary = 30%x1320= 396 Cal
 Change from Moderate to Sedentary Activity

= gain 41 pounds of fat per year!!
Thermic Effect of Food
 Increased
energy expenditure
after a meal.
5-10%
 Cost
of BMR
of digestion, absorption, &
assimilation of nutrients
 Ex: 5% x 1320 = 60 Cal
Estimation of E(out)
 E(out)
= BMR + Act + TEF
Example:
 E(out)



= 1320 + 530 + 60 = 1910 Cal
BMR = 69% of E(out)
Act = 28% of E(out)
TEF = 3% of E(out)
Healthy Weight and the
Non-Diet Approach
David L. Gee, PhD
Professor of Food Science and Nutrition
Central Washington University
Prevalence of Overweight in the
US

1990: 56% of Americans were overweight


2000: 64% of Americans were overweight


30% were obese
At this rate




23% were obese
In 2010: 73% overweight
In 2020: 84% overweight
In 2030: 96% overweight
Increases in overweight/obesity were seen in:



Both males and females
All age groups
All ethnic groups
The increase in prevalence in people with BMI > 25 was almost
Entirely due to increased prevalence of obese!!!
Overweight may be a transitional state for most Americans !!!
Ethnicity and Overweight
(BMI>27.5) Prevalence
70
66
63
60
50
45
42
40
%
30
24
27
31
40
34
26
20
10
0
White
Black
Hispanic
Native Am Hawaiian
Male
Female
Epidemic Increase in Childhood
Overweight, 1986-1998
JAMA 286:2845-2848 (2001)

National Longitudinal Survey of Youth
 1986-1998
 8,270

children, aged 4-12 yrs
Prior studies show it took 30 years for
overweight prevalence to double. Current
study show doubling time to be less than 12
years.
 Rate
of increase particularly high in African
American and Hispanic children
Prevalence of Overweight Children in the US
Epidemic Increase in Childhood
Overweight, 1986-1998
JAMA 286:2845-2848 (2001)
Prevalence of overweight in
children.

CDC (2004)
= above the 95th percentile for BMI
based on NHANES II data from 1970’s
 For adolescents 12-19 yrs:
 Overweight
1974 = 7.4%
 2002 = 15.6%

 Recent
UW report (2007) that up to 25% of WA
children are overweight.
Genes/Biology vs
Environment
 Overweight
is a result of both
 Adoption studies (biology)
 Adopted
adults have BMI that are more similar to
biological parents than to adoptive parents.
 Animal
studies (biology)
genetically
Genes
obese rats and mice
identified & biology explained
Genes/Biology vs Environment
(cont.)
 Migration
studies (environment)
 Japanese
 Hawaiian
Japanese
 Californian Japanese
 Dietary
Change Studies
(biology and environment)
SW
Native Americans
Pima Indians
 Mexican Pima Indians
subsistence farming & ranching
20% fat diet, 40 hrs/wk physical work
 Arizona Pima Indians
mechanized agriculture, sedentary
lifestyle
40% fat diet
Pima Indians
Arizona
1
Pima Indians are:
inch taller
57 pounds heavier
70% obese
50% with diabetes by age 35
Genes vs Environment:
Conclusions
 Genes
for weight gain
predisposes some individuals
towards weight gain.
 Environment determines which
of those individuals actually
gain weight.
Why lose weight?

Obesity is associated with greater risk of:
 Diabetes
 Hypertension
& stroke
 Coronary heart disease
 Most cancers (except lung cancer)
 Sleep apnea, arthritis, gall stones, ….

Overfat vs Underfit ????
 Good
 In
question!
reality: Vast majority of overfat are underfit
Obesity and Causes of Death in the US
The Cost of Obesity
Health Affairs, Aug 2006
Year
% of Medicare % of Medicare
Patients with
spending on
obesity
obese patients
1987
11.7%
9.4%
2002
22.5%
24.8%
$336 billion 2005 total Medicare expenses
What is a “Healthy Weight”?
A broad
range of weight
which allows for minimal
risks for chronic diseases.
Goes beyond using only
body weight as a criteria for
good health.
Determination of your "healthy
weight".
 Step
1. Body Mass Index
BMI
= BW(kg)/Ht2(m2)
 Dr. Phil
 from Nutrition Action Health Letter, Jan. 2004
6‘4"
= 78" x 0.0254(m/in)= 1.93m
240lbs / 2.2(lb/kg) = 109kg
 BMI

= 109/(1.932)=109/3.72
= 29.3
BMI Classifications
BMI = 19 - 25 => Desirable
 BMI = 25 - 30 => Overweight
 BMI = 30 - 35 => Obese, category 1
 BMI = 35 - 40 => Obese, category 2
 BMI > 40
=> Severe obesity
 “Healthy weight is a broad range of
weight…”

 For
5’10”, BMI 19-25
 = 132 – 174 lbs
Is BMI a good screening tool for
weight problems?
BMI measures degree of overWEIGHT
 BMI does not directly measure
overFATNESS
 But….

 Strong
population-based relationship between
high BMI and morbidity and mortality
 BMI a good predictor of overfatness in middleaged and older Americans
BMI and Mortality Risk
BMI and Prevalence of Low HDL
NHANES III
BMI and Prevalence of Hypertension
Healthy Weight (cont.)
If
your BMI > 25, then
consider presence of other
health risk factors.
Healthy Weight (cont.)
 Body
Fat Distribution
 upper
body fatness associated with
higher health risks
 Waist Circumference (1998 NIH)
>
35” for females,
> 40” for males
Healthy Weight (cont.):
Know your blood lipids!
 Hyperlipidemia/dyslipidemia
TC
> 240 mg/dl
LDL-C > 160 mg/dl
HDL-C < 40 mg/dl
TG > 200 mg/dl
Healthy Weight (cont.):
Know your blood pressure!
 High
Blood Pressure
Systolic
BP > 140 mm Hg or
Diastolic BP > 90 mm Hg or
Borderline
>130/85
or Pre-hypertensive
Healthy Weight (cont.):
Know your blood sugar and history
 Hyperglycemia (Diabetes)
Fasting

Blood Glucose
> 126 mg/dl
Impaired
Glucose Tolerance
Pre-diabetic

>110 mg/dl
 Gestational
Diabetes
 Family History of Diabetes
Healthy Weight Summary

If your BMI is 19-25, you are at a Healthy
Weight.
 Health
problems are not weight related
If your BMI is > 25 and you have no other
risk factors, you are at a Healthy Weight.
 If your BMI is > 25 and you have one or
more risk factors, you are NOT at a Healthy
Weight.

 Weight
loss is likely to improve your health
Should everybody who is overweight try to
lose weight?
Will weight loss improve your quality of life?
A Prospective Study of Weight Change and Health-Related
Quality of Life in Women
JAMA Dec. 1999
 Nurse’s Health Study

 40,098
women, 4 yr longitudinal study
 Weight changes
 Quality of life questionnaire
 Physical
function
 Vitality
 Freedom
from bodily pain
 Mental health
The effect of weight gain/loss on:
Vitality Score

Weight gain:


associated with
declines in
vitality scores in
all BMI
categories
Weight loss

associated with
improved
vitality scores
only in women
with BMI>25
The effect of weight gain/loss on:
Mental Health Score

Weight gain


associated with a
decline in mental
health scores in
all weight
categories
Weight loss

associated with
improved mental
health scores only
in obese class I
women and
declined in
normal weight
women.
A Prospective Study of Weight Change and
Health-Related Quality of Life in Women.
Conclusions:

For women at all BMI categories:
 Don’t
gain weight
 Reduced quality of life

For overweight and obese women:
 Weight
loss is generally associated with improved
quality of life

For normal weight women
 Weight

loss does not improve quality of life
May actually reduce quality of life
The Obesity Epidemic in America:
Who’s responsible?

Personal responsibility
Environmental influences

Do we need a “Food Police”?

 http://www.nytimes.com/2005/06/12/business/yourmon
ey/12food.html?pagewanted=1
Bottom Line on Weight Loss

Lose weight for the right reasons
 Improve

health and your quality of life
Losing weight to attain the ‘perfect body’
 May
lead to frustration
 And,
 May
ironically, weight gain
lead to eating disorders
Dietary Means to a Healthy Weight

Weight loss occurs when in negative energy
balance

Weight loss is only half the battle
 Maintenance
problem
of weight loss is the critical
Dietary Means to a Healthy Weight
Balanced Reduced Calorie Diet

Characteristics
 Calories
reduced by 500-1000 Cal/day
 CHO:PRO:FAT = 50-60%: 10-15%: 20-30%

Examples
 Weight

Watchers, Jenny Craig, Slim Fast
What the research shows:
 Short-term

Modest weight loss, improved health
 Long-term

outcomes
outcomes
Success rate not great
Dietary Means to a Healthy Weight
Low Carbohydrate Diets

Characteristics
 Very
low in CHO
 Restricted intakes of fruit, cereals, pasta, bread,
potatoes, rice
 Caloric intake not specified

Examples
 Atkins

diet
What the research shows:
 Short-term

6 month studies, good weight loss, no substantial change in
heart disease risk factor, drop-out rate significant
 Long-term

outcomes
outcomes
No long term studies, health risks?, 1 yr studies show more
weight regain compared to low-fat diets
Dietary Means to a Healthy Weight
The Carbohydrate ‘Restrained’ Diets

Characteristics
 Lower
in CHO than Dietary Guidelines but
higher than Low Carb diets (~40% CHO,
30%FAT, 30%PRO)
 Low glycemic index foods encouraged
 Monounsaturated fats encouraged

Examples
 Zone

Diet, South Beach Diet
What the research shows:
 Little
research available on these diets
Dietary Means to a Healthy Weight
Healthy Diet/Non-Diet Approach

Characteristics
 Focus
on quality of the diet, not quantity
 Attaining good health is primary goal, not weight loss

Examples
 DASH

diet, Dietary Guidelines, Food Guide Pyramid
What the research shows:
 Short-term

outcomes
Slow, limited weight loss, health benefits
 Long-term
outcomes
U. Colorado’s Weight Loss Registry
 Diet most adopt in order to maintain weight loss

Exercise and Weight Loss

U. Colorado’s Weight Loss Registry
 Exercised
used by nearly 100%
 Walking the most common form of exercise

Benefits of Exercise
 Rate
of weight loss greater
 Caloric restriction not as great
 Quality of weight loss better
 Proactive choice vs dieting
 Health benefits independent of weight loss
Rates of physical inactivity in the US
Exercise and Weight Loss
Structured Exercise

Aerobic Exercise
 Burns
more calories, more fat
 Stress duration initially

Strength Training
 Builds
more lean tissue
 Increases basal metabolic rate
Exercise for Weight Loss:
Walking vs Running
Going 4 miles
Calories burned
Walking @
15min/mile
400 Cal
Jogging @ 8
min/mile
400 Cal
Fuels burned:
CHO:FAT
Calories CHO
50:50
75:25
200 Cal
300 Cal
Calories FAT
200 Cal
100 Cal
Exercise for Weight Loss:
Walking vs Running
Going 1 hour
Distance covered
Walking @
15min/mile
4 miles
Jogging @ 8
min/mile
7.5 miles
Calories burned
400 Calories
750 Calories
Fuels burned:
CHO:FAT
Calories CHO
50:50
75:25
200 Calories
560 Calories
Calories FAT
200 Calories
190 Calories
Exercise for Weight Loss:
Walking vs Running

Conclusions
 Walking
and running burn the same number of
calories over the same distance
 Walking burns more fat than running over the
same distance
 Running burns calories at a faster rate and
improves cardiovascular fitness more.

Bottom line: Just do it!
 Either
type of exercise is beneficial
Exercise and Weight Loss
Structured Exercise

Characteristics of Successful Programs:
 Convenient
 Enjoyable
 Safe
 affordable
 Subject
realizes net benefit over costs
Exercise and Weight Loss
Lifestyle Activity

24 hr day
 Sleep/rest
= 10 hrs
 Structured exercise = 1 hr
 What you do the remaining 13 hrs of the
day?

Burn extra 25 Cal/hr = 325 Cal/day
=



33 pounds of fat loss per year
Develop a new attitude about being
active
Pedometers and 10,000 step programs
Health benefits significant
Weight Loss/Weight Maintenance
Behavior/Attitude Changes

Pay attention to what you eat
 Success

Examine:
 Triggers

for eating
Emotional eating
 Risky

of weight loss programs
situations
Behavior Modification Programs
 Track/record
eating behaviors
 Identifies problems
 Sets goals and establishes rewards
 Continual reassessment/problem solving
For more severe weight loss:

Prescription Drugs



For those with BMI > 30 or
For those with BMI >27 and risk factors
Meridia (Sibutramine, Abbott Lab)

Suppresses appetite


Xenical (Orlistat, Roche)

Inhibits fat absorption



Increases brain serotonin & norepinephrine levels – signal for satiety
Reduces calories from fat containing foods
Results in “adverse reactions” if eating high fat foods
Long term success and risks


Meridia – hypertension
Xenical – steatorrhea (fatty diarrhea)
For those with Severe Obesity

Surgical Methods
 For
those with BMI >40
Carnie Wilson
Al Roker
For those with Severe Obesity

Gastroplasty
 Reduces
size of stomach by
banding or stapling

Gastric Bypass Surgery
 Reduces
size of stomach
 Bypasses much of the small
intestine

Outcomes
 Rapid
and substantial weight
loss
 Side effects
 Dangers
Advice for the ‘typical’ CWU student:

If you are at a healthy weight:
 Keep
a close eye on your weight
 Preventing
weight gain is far easier than trying to
lose weight.

If you are at an unhealthy weight:
 Don’t
gain any more weight!
 If you try to lose weight
 Set
reasonable goals (10% in 6 months)
• Weight, diet, exercise
 Permanently
change your lifestyle