Body Composition and
Weight Control
By Jennifer Turley and Joan Thompson
© 2016 Cengage
Presentation
Overview
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•
•
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Body Composition
Body Weight verses Body Fat
Fat Distribution
Combating Obesity (Effective
Weight Loss)
• Diet Planning for Nutrient Adequacy
Body Composition
• Determination of body weight should be
based upon body composition.
• It is important to know the % of total
body weight that is fat.
• Values should be considered for
maintaining good health, personal
appearance, & performance reasons.
Healthy Body Composition
• Lean body mass ~55% of total body
weight (muscle is ~70% H20)
• Essential fat mass
– 3% body fat in men, 12% body fat in women
• Stored fat mass is variable ~ 15-20%
(Additional fat beyond essential fat is stored)
• Minerals ~4% of total body weight
• Water ~ 60% of total body weight
Body Weight vs. Body Fat
The best way to determine obesity is to
determine the % of body fat.
 A man is too fat if ≥20% body
fat.
 A woman is too fat if ≥26% body
fat.
The scale doesn't accurately tell
body fat
Interpreting Body Fat
Body Fat
Categories
Essential Fat
Very Lean
Lean
Physically Fit**
Not Fat (Average)
Fat*
Obese
% Body Fat
MALE
% Body Fat
FEMALE
3
12
≤10
11–15
12–15
16–19
20–27
> 28
≤13
14–19
18–22
20–25
26–32
> 33
*Strong recommendations for fat cell reduction are made when males
exceed 20% body fat, and females exceed 26% body fat.
**If you are male and less than 12% or a female and less than 18%
body fat, you may interpret the result as being physically fit.
Determining Body Fat
• Underwater weighing (very accurate)
• Bod Pod (very accurate)
• Skin fold calipers (the more sights,
the better)
• Bioelectrical impedance (the persons
hydration level affects the reading
accuracy)
• Futrex 5000 (more accurate when
average body fat)
• Research Techniques (DEXA, MRI,
total body potassium, substance
dilution)
Method
s of
Calcula
ting
Body
Fat
Fat Distribution
Gut vs. Butt
• Central adiposity
(obesity) has
increased health
risks:
– Type 2 diabetes
– Hypertension
– High blood
cholesterol
– Dyslipidemia
– Heart disease
Visceral versus
Subcutaneous fat
Central Adiposity
Android Obesity & Apple Shape
Determined by waist measurement.
 Male waist measurement > 40
inches = central adiposity & apple
shape.
 Female waist measurement > 35
inches
= central adiposity & apple
shape.
Gynoid Obesity
Pear Shape
• Pear shape is determined by a
large hip measurement.
• Subcutaneous fat
accumulates around the hips.
• Is not as detrimental to health
as visceral fat accumulation in
the abdominal cavity.
Body Mass Index (BMI)
• Indicates the healthiness of body
weight in relation to height.
• Is not an accurate measure of %
body fat.
• A BMI ≥ 25 and a waist
circumference of >40 inches for
men or >35 inches for women
places an individual at increased
risk for:
– Heart disease, Hypertension,
Dyslipidemia, & Type 2 diabetes.
Calculating BMI
BMI = Weight (Kg)
Height (M)2
Conversions:
Kg = Pounds ÷ 2.2
M = Inches ÷ 39.37
Do not forget to square the height in meters
or your math will falsely indicate obesity!
Sample Calculation
John weighs 182 pounds and is 68 inches
tall, What is his BMI?
•182lb ÷ 2.2 = 82.73Kg
•68 inches ÷ 39.37 = 1.73 Meters
•1.732 meters = 2.99 Meters squared
•(M2 could also be calculated as 1.73 x 1.73 =
2.99 Meters squared)
John’s BMI =
82.73 Kg
= 27.7
2.99 M2
People with high LBM may have a high BMI but are not
obese.
It is a good idea to determine body composition on all
individuals who have a BMI that is ≥25 to confirm obesity.
Interpreting BMI
BMI
<18.5
18.5-24.9
25-29.9
30-34.9
35-39.9
≥40
Risk
Underweight
Normal
Overweight
Class I Obesity
Class II Obesity
Extreme Obesity
Combating Obesity,
Part 1
Surgery:
• Lipo-suction
• Intestinal
resection
• Gastric bypass
• Gastric band
Drugs:
• Over the counter
& prescribed
These
methods can
be Health
threatening
& usually do
not result in
long-term
sustained
weight loss
and/or a
healthy
lifestyle
Combating Obesity, Part 2
Diets: Low carb &/or very low Calorie
• There is 6% success rate for reducing
weight and maintaining the weight loss
by dieting.
• During prolonged fasting (or low calorie,
low carb diets), the BMR declines and
lean body mass is used to make glucose
for brain, central nervous system, and
red blood cell functioning.
• The body chemistry changes under
conditions of Feasting & Fasting
Feasting
Short Fasting
Long Fasting
Weight Control
• When considering weight loss,
it is important to lose the
excess fat weight and
preserve the lean body mass
or muscle.
• The reason for weight loss
should be to decrease excess
of body fat.
• Fat weight loss is a slow
process.
Effective Weight Loss
• Optimal weight loss rate is 1
lb/week.
• 1 lb of fat weight loss requires
a 3500 Calorie deficit.
• A 500 Calorie deficit per day
times 7 days per week
produces a rate of weight loss
of 1 lb/week.
500 Calorie Deficit/Day
• 40 minutes aerobic exercise = 300 Calories
(preserves LBM, BMR and utilizes stored fat)
• 22g of dietary fat removed from the diet =
200 Calories.
• Results in:
– 1 pound per week of body fat lost.
– Preservation of lean body mass.
• A faster rate of weight loss forces the body
to use muscle protein to meet the
glucose/energy needs of the body.
Benefits of Exercise
It promotes
Cardiovascular fitness
Higher HDL levels
Lower resting heart
Burning 2000-3000
rate
Calories per week
Lower blood pressure
reduces disease
More LBM
Flexibility, strength &
Over exercising one area
endurance
of the body does not
Healthy body weight
result in spot reduction
Better mental outlook
Making the Changes
• Incorporating the dietary changes
and the exercise behaviors
permanently into the lifestyle
requires a step process.
• A progressive behavior modification
program can facilitate successful
lifestyle changes.
Behavior Modification
• Identify goal (realistic).
• Identify current behaviors that need to
change.
• Identify behaviors that will achieve the goal &
reinforce them.
• Commit to change.
• Plan (set realistic small behavior changes
into action, rewards).
• Persist long enough to see results, reinforces
motivation.
• Evaluate the progress & modify the plan
Life Long Diet Protocols
Greater long term success rates with:
1. Eating a well balanced diet from a
variety of foods to achieve nutrient
adequacy.
2. Incorporating an hour-long exercise
program daily.
3. Using behavior modification to
permanently incorporate desired
health behaviors
What is Nutritional
Adequacy?
The diet provides:
• Essential nutrients
• Fiber
• Energy
to maintain health.
When should it be
considered?
• Nutritional adequacy should be
considered for each individual diet.
• In weight loss, weight maintenance
or gain diets, nutritional adequacy
should also be considered.
How is it measured?
Dietary assessment tools like:
• Diet Analysis software programs
• Food Composition tables & databases
• The Exchange System
Used to prescribe & monitor dietary intake.
How is it interpreted?
• All diets (especially weight control diets)
need to be planned so that there are no
nutritional inadequacies, deficiencies, or
risks for toxicity.
– Inadequate Intake: < 100% of the DRI
– Deficient Intake: < 66% of the DRI
– Risk of Toxicity: > 100% of the UL
Applies to all nutrients
with DRIs and/or ULs
What other factors
should be considered?
The diet should be planned to promote
health by limiting:
• Saturated & trans fatty acids,
cholesterol, simple sugar, & Sodium.
• Plan intake of Calories from carbs,
protein, and fat to meet AMDR.
Some Summary Points, Part 1
• Individuals need to know their
body composition (LBM vs. Fat
Mass).
• There are different methods to
determine body composition.
• The distribution of body fat
affects health (visceral verses
subcutaneous fat).
Some Summary Points, Part 2
• BMI is a recommended measure for
determining appropriate body weight
for height.
• A slow rate of weight loss is
suggested to preserve lean body
mass while reducing fat mass.
• Lifelong diet and exercise habits
should be practiced for optimal body
weight, health, and nutrient
adequacy.
References for this presentation are the same as those for this topic found in
module 4 of the textbook