Transcript Energy Balance and Weight Control

Healthful Body
Weight
Chapter 11
"To lengthen thy life, lessen thy meals."
-Benjamin Franklin
USATODAY.com - Obesity alone puts heart in
jeopardy
Quote of the Week
If we could give every individual
the right amount of
nourishment and exercise, not too
little and not too much, we would
have found the safest way to
health.-Hippocrates
"Self delusion is pulling in your
stomach when you step on the
scales."
Basal Metabolic Rate

Energy essential for life support
– circulation
– respiration
– temperature maintenance
– nerve transmission
– kidney function, etc
Factors Affecting BMR
 Decrease:
–aging
–short and stout
–fasting and starvation
–female
Factors Affecting BMR
 Increase:
– growth
– lean body mass & tall
– male
– Fever, stress
– pregnancy/lactation
– increase in thyroxin
Thermal Effect of
Food
 TEF
= Thermal effect of food
 Increased energy expenditure
after a meal.
 5-10% of BMR
 Cost of digestion, absorption, &
assimilation of nutrients
 Ex: 5% x 1320 = 60 Cal
Total Energy
 TE
= BMR +TEF + Activities
 Activities: Any voluntary activities
–
–
–
–
–
–
Sedentary 25-35% BMR
Light 35-50%
Moderate 50-70%
Heavy >70%
http://www.americaonthemove.org/
USATODAY.com - Study: Obesity rises faster in
poor teens
TE Example
If BMR = 1200
 Then TEF x 0.1 = 120
 If Activity is moderate = 1200 x 0.5 =
600
 Then TE = BMR +TEF + Activity
 TE = 1200 + 120 + 600 = 1920

Energy Balance

When E (in) = E (out)
– no weight change

When E (in) < E (out)
– weight loss

When E (in) > E (out)
– weight gain
Energy (in)
Calories = 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.
Measurement of E (out)

Direct Calorimetry
– measures heat directly
– bomb calorimeter (for food)
– room calorimeter

Indirect Caloroimetry
– measures oxygen consumed or
– carbon dioxide produced
Whole Body
Calorimeter
Room Calorimeter
Indirect Calorimetry
Estimation of Energy
Out
Example: 55kg male
 BMR = 1 Cal/kg /hr
 BMR = 55 x 1 x 24 = 1320 Cal/day
 TEF =.05 x 1320 = 60 Cal
 Act = .40 x 1320 = 530 Cal
 TE = BMR + TEF + Act
 1910 = 1320 + 60 + 530

Estimating Calorie
Requirements
 Mifflin-St.Jeor
Men: 10 x wt (kg) + 6.25 x ht (cm) –5 x
age + 5
 Women: 10 x wt (kg) + 6.25 x ht (cm) –
5 x age - 161

Mifflin-St. Jeor
Woman: 5’6” tall, 130#; 30 years
 Works as secretary
 (10 x 59) + (6.25 x 167.7) – (5 x 30) –
(161) = 1327 kcal

Definitions
 Underweight
 Overweight
 Obesity
 Morbid
obesity
 Study: Super-sizing your food
takes a hidden toll on your
pocketbook
Body Weight VS Body
Fat
How to determine if weight is
optimum?
 Ideal Body Weight Determination

– Males: 106 # for first 5 ft
 Then
6 # per inch above 5 feet
 eg: 6 ft individual 5ft= 106 # + (12x6) = 178#
 so 178 + 10% is ideal body weight
– Females: 100 # for first 5 ft
 Then
5 # per inch above 5 ft
Ways to determine
Ideal Body Weight

Weight for Height Tables:
– Metropolitan Life Insurance Table
– Height & Weight Tables

Body Mass Index
– Wt (kg)/ height (MxM)
– or (weight (lb)/ height (in x in) )x 705
– eg 5’10” person weighing 150 #


BMI = (150/ (70 x70)) x 705 = 21.6
compare to table
BMI Classifications






BMI = 18.5-24.9; Normal; Low Risk
BMI = 25-29.9; Overweight; Some Risk
BMI = 30-35; Class 1 obesity; High Risk
BMI = 35-40; Class 2 obesity; Very High
Risk
BMI> 40; Class 3 obesity; Extreme Risk
Body Mass Index Chart
What do these men have
in common?

They are “obese” by BMI standards
 Is Your Weight Killing You?

Changing Times

'Miss America' Body Type Isn't
American at All Reuters Health

Miss America pageant winners are
thinner than ever before, and look
nothing like the average US woman,
new study findings suggest.
Comparison of Methods
(24 yo male, 5’10”,
average frame)







1. 5’ = 106 # + 6# x 10” =166 #
2. Met life. 1999: 151-163, 1959:143-158#
3. BMI. 18.5-24.9 = 127.6-173#
4. US NCHS. 166#
5. NAASO. 166#
6. US Army. 185#
Range 127.6-185
Other Methods of
Determining Body
Composition
Under water weighing (hydrostatic
weighing)
 Skinfold test
 Bioelectrical impedance
 Near Infrared Reactance
 air displacement (Bod Pod)
 Dual energy X-ray absorptiometry
(DEXA)

Hydrostatic Weighing
Skinfold Test
Visceral Fat and
Subcutaneous Fat
Bio Electrical
Impedance
Near Infrared
Reactance
Bod Pod
DEXA
Body Fat
Male
Female
Athlete
<10%
<17%
Lean
10-15%
17-22%
Normal
15-18%
22-25%
Above ave
18-20%
25-29%
Over fat
20-25%
29-35%
Obese
25+%
35+%
Obesity





BMI > 30
BW > 20% of standard
% body fat: women > 35%, men > 25%
Prevalence - 31% obese, 64% overweight
Blackwell Synergy: Nutr Bulletin, Vol 31,
Issue 2, pp. 111-114: Obesity and type 2
diabetes (Abstract)
Mystery of Obesity
 Hunger
–physiological
 Appetite
–learned
 Satiety
–GI track
Causes for Obesity

Internal Causes
– Genetic Inheritance

Leptin: a protein found that suppresses appetite in
animals and increases metabolism
– Overweight animals lack Leptin
– Overweight people aren’t as responsive to Leptin
as are normal weight people. Leptin is actually
higher in overweight people than normal weight
people
– Leptin replacement therapy to fight obesity?
– ABC News: Can Geneticists Cure Obesity?
Genetically
Obese: Lacks
Gene for Leptin
Genetically
Obese: Lacks
Gene for Leptin
Receives Leptin
No Leptin
Thrifty Gene Theory
 Thrifty
metabolism
 Conserve energy
–No gene identified
Set Point Theory

Body adjusts to low intake of Calories
– Reduce metabolic rate
– Conserves Calories
Food Insecurity
Obesity Trends
Enzyme Theory

Lipoprotein Lipase
– Picks up triglycerides from lipoproteins in
the blood and stores it in fat cells
– High activity of LPL associated with
increased weight
Gene vs Environment:
Conclusions
Genes for weight gain predisposes
some individuals towards weight gain
 Environment determines which of
those individuals actually gain weight
 The Seattle Times: Food & wine:
Super Bowl snack stats to whet your
appetite

Weight Gain
E (in) > E (out)
 Which nutrient in excess causes
weight gain?
 How

– CHO
– Protein
– Fat
– Alcohol
Feasting and Fasting, 1 of 3
Weight Loss


E(in) < E (out)
The body’s response to fasting
– glycogen and fat stores
– body protein and fat stores


The body’s response to CHO restriction
Solution
– decrease energy in
– increase energy out
– Nutrition Research - adherence to diet
determines success
Feasting and Fasting, 2 of 3
Feasting and Fasting, 3 of 3
Weight loss diets

Weight Watchers and Slim-Fast top
diet ratings - Diet and Fitness MSNBC.com
– Wholegrains strongly associated with
keeping
weight off
WIN - Publication - Weight-loss and
Nutrition Myths
FTC Warnings


Products and programs that promise quick
and easy weight loss are bogus. To lose
weight, you have to lower your intake of
calories and increase your physical activity.
The faster you lose weight, the more likely
you are to gain it back. Experts recommend
a goal of about a pound a week.
FTC Warnings
There are no miracle weight-loss
products. Be skeptical of products and
programs that claim they can keep
weight off permanently. Be skeptical
about exaggerated claims.
 FTC Launches “Big Fat Lie” Initiative
Targeting Bogus Weight-loss Claims

Gastroplasty

Gastric Bypass
Gastric Banding