Body Composition and
Weight Control
By Jennifer Turley and Joan Thompson
© 2013 Cengage
Presentation
Overview
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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  12% body fat in 
• 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.
  is too fat if ≥20% body fat.
  is too fat if ≥26% 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)
Under Water Weighing
Electrical
Impedance
Bod Pod
Skin Fold Calipers
Fat Distribution
Gut vs. Butt
• Central adiposity
(obesity) has
increased health
risks:
– Type 2 diabetes
– Hypertension
– High blood
cholesterol
– Dyslipidemia
– Heart disease
Central Adiposity
Android Obesity & Apple Shape
Determined by waist measurement.
  waist measurement > 40 inches
= central adiposity & apple shape.
 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
Surgery:
• Lipo-suction
• Intestinal
resection
• Gastric bypass
• Gastric band
Drugs:
• Over the counter
& prescribed
Combating Obesity
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 rate
• Lower blood pressure
• More LBM
• Flexibility, strength &
endurance
• Healthy body weight
• Better mental outlook
Burning 2000-3000
Calories per week
reduces disease
Over exercising one area of the body does not
result in spot reduction
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
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.
Summary
• 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).
Summary
• 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