Transcript Managing Your Weight: Finding a Healthy Balance

Chapter 8
Managing Your Weight:
Finding a Healthy
Balance
WEIGHT CONTROL AND
HEALTH
Health risks associated with
excess adipose tissue and
inactivity:
• heart disease
•
•
•
•
diabetes
hypertension
cancer
osteoarthritis
Also question of self-concept
and emotional health.
BODY COMPOSITION
Total body mass is
composed of 2
components:
• fat mass (FM)
• fat-free mass (FFM)
(composed of muscles,
bone, water, and
viscera)
Body composition is influenced by
• genetic factors
• environmental factors
• nutrition
• disease
• physical activity
BODY FAT MASS
• energy
• storage / vitamins
• protects internal organs
• insulates body against
extreme cold
Essential Fat
• essential fat required
for normal function
of CNS
• stored in muscles,
heart, lungs, liver,
spleen, intestines,
kidneys + bone
marrow
• men is 3%
• women is 12%
Storage Fat (subcutaneous fat)
• storage fat is deposited in
adipose tissue - energy
• # of fat cells remains
constant - size reduced
• location of storage fat
varies
• protects internal organs
G en era l R a tin g o f B o d y F a t % b y A g e a n d S ex
R a tin g
M a les
F em a les
(a g es 1 8 -3 0 ) %
(a g es1 8 -3 0 ) %
E ssen tia l
3
12
A th letic
6 -1 0
1 0 -1 5
G ood
1 1 -1 4
1 6 -1 9
A ccep ta b le
1 5 -1 7
2 0 -2 4
O verfa t
1 8 -1 9
2 5 -2 9
O b ese
20+
30+
HEALTH RISKS
Underweight
Overweight
• nutritional
deficiencies
• anemia
• heart disease/defects
• chronic fatigue
• infection
• depression
•
•
•
•
•
hypertension
diabetes
heart disease
orthopedic problems
respiratory problems
Body Fat Distribution
• gender differences
• approx. 9-yr. boys deposit
fat - abdomen
• approx. 9-yr. girls deposit
fat - hips and legs
• differences accentuate with
puberty and maturation
Body Fat Distribution
• men - android pattern apple-shaped (fat stored
in trunk, chest, back, and
abdomen)
• women - gynoid pattern pear-shaped (fat stored
in hips and legs)
FAT-FREE MASS (FFM)
• muscle, skin, bone, and
viscera
• midlife FFM declines/men
and women/decrease in
muscle mass
• FFM decreases 3 kg per
decade/1.5 times greater in
men than women
• decrease of FFM/decrease in
growth hormone with aging
• physical inactivity
OVERWEIGHT OR OVER-FAT?
WAYS TO MEASURE BODY FAT AND BODY
COMPOSITION
• Body Weight vs.
Body Composition
• Scales = Body Weight Only
• Body Mass Index (BMI) =
mass (kg)
stature (m2)
• Men > 27,8 = overweight
• Women >27,3 = overweight
• BMI >30 = obese
WAIST TO HIP RATIO
• correlation between fat stored
in mid-section and disease
• divide waist measure by hip
measure
• if above 0.8 for females and
>0.95 for males people risk
for heart disease, high blood
pressure and diabetes.
SKINFOLDS
• measure of subcutaneous
fat
• fifty percent of body fat
beneath skin - therefore
percentage body fat can
be calculated from
skinfolds measures
• subject to error
RESEARCH SETTINGS AND
BODY FAT EVALUATION
• total body electrical
conductivity (TOBEC)] electromagnetic force field
• bio-electrical impedance
(BIA) - pass current through
body
• soft-Tissue Roentgenogram inject radioactive substance
into lean body mass…….
Muscle - Fat Mass ID
Hydrostatic Weighing Techniques
• Determines fat mass
by submerging the
body in waterdisplaced water is
measured
• densities of lean and
fat mass are known
• compares out-ofwater and underwater weight
CAUSES OF OBESITY
Heredity
• Twins research: different family
Environments - Same Genetic
Make – Up
• 1 parent obese = 55% - children
tendency to being overweight or
obese
• 2 parents obese = 90% - children
tendency to being overweight or
obese
Heredity Continued….
• neither parent obese =
15% chance children will
tend to be overweight or
obese
• genes set metabolic rates
• nutritional choices +
exercise can modify the
genetic effect
Exercise / Lifestyle
• Increases metabolic
rate- up to several
hours after exercise
• F.I.T.T. principles
• energy from stored
Fat/CHO/Protein
• critical component –
reset the Set Point
• one pound of body fat
contains 3500 calories
Errant Eating & Thrifty Genes
Errant Eating:
• “I’ve had enough to
eat” - defective gene
Thrifty Genes:
• survival mechanism
when food isn’t
available…..
• lower metabolic rate
Metabolic Rates
• BASAL METABOLIC RATE - lean
muscle mass vs. fat mass
• RESTING METABOLIC RATE =
BMR + other sedentary activities
( 90%) of Energy
• EXERCISE METABOLIC RATE =
RMR (90%) + Moderate to Heavy
Activity (10%)
• Opportunity for Weight Loss
Fat Cell Theory
Approximate Number of
Fat Cells (ADULT)
• Average Weight – 25 to 30
Billion
• Moderately Overweight –
60 to 100 Billion
• Obese – 200 Billion
Fat Cell Size
• Hypertrophy (SIZE)
Adults and children
• Hyperplasia (NUMBER)
Last-Trimester Pregnancy
(Mother’s Dietary Habits)
• 1st Year of Life
• 9 to 13yr.
• extremely obese people
Set Point Theory
• internal control mechanism
for body to maintain certain
weight
• research into dieting - lowers
the metabolism - dieting
ineffective (95%) - need
lifestyle changes as well
• also work done with
overfeeding -similar shift but
in opposite direction
Psychosocial Factors:
• Emotional insecurities,
childhood rewards,
unemployment, broken
relationships, financial
uncertainty, etc, etc…
• A Bright Spot … FOOD…!
• Eating is a social ritual –
companionship, celebration,
enjoyment….an event!
Eating Habits:
• Learned and
perpetuated by
family?
• Situation?
• Money?
• Break the Cycle –
Food & Eating
Analysis
SUCCESSFUL WEIGHT
MANAGEMENT
Role Of Diet /Nutrition:
• balanced nutrition vs. a ”diet"
• initial losses mostly water
• impairs physical function
• lowers basal metabolic rate
• repeat dieting leads to
greater fat levels
• severe restrictions alter
the optimal balance of
nutrient intake
Weight Loss
Set Goals
• improve quality
of life through
lifelong weight
management
• weight loss
approximately 1
lb. / week
Changing Attitudes
• examine reasons for eating track behaviors that trigger
eating
• Keep track of what you eat,
when, and why!
• Hypothalamus senses hunger
while the
• SATIETY CENTRE sends
indication of fullness.
Changing Attitudes
• A 20 minute delay occurs
for satiety to be felt
• water / fruit before eating
• behavior modification is
essential to any successful
weight management
program
ROLE OF EXERCISE
• Very important moderate will suppress appetite
• lean muscle development
results in greater
"burning" of calories
• basal metabolic rate
• resting metabolic rate
• exercise metabolic rate
DANGERS OF QUICK-FIXES
behaviours aren’t changed
• gastric balloon insertion
• stomach stapling
• jaw wiring
• liposuction
• new behaviors are not
learned
• always dangerous i.e.
health and life!
DISORDERED EATING & Eating Disorders
ANOREXIA NERVOSA:
• a morbid fear of being fat
• relentless pursuit of thinness
• condition in which a very thin
body is seen as normal
• distorted body image
• suppression of appetite rather
than loss of appetite
ANOREXIA NERVOSA
• self-induced starvation or
dieting gone out of
control
• starvation and over
exercise are common
• many social classes and
ethnic groups
• often well educated,
achievement oriented
ANOREXIA NERVOSA:
• results in death in 5 to 18% of cases (suicide
or medical complication)
• decrease in food intake
• increase in purging ( self-induced vomiting)
• misuse of laxatives or diuretics
• dangerous exercise habits
• affects bones, muscles, organs, immune
system, nervous and digestive system
ANOREXIA NERVOSA:
– tooth decay – vomit
– (stomach acids) dissolves
enamel
– hair loss & development of
fine hair on face and body
Treatment
• multifaceted medical
and psychological
• drug therapy and
behavior
modification used
• prognosis often poor
BULIMIA NERVOSA
FEELING A LACK OF CONTROL
• uncontrolled
binge
eating followed by
vomiting /purging the
body of food
• purging through use of
vomiting,
laxatives,
diuretics, exercise
• 95% are female
BULIMIA NERVOSA
• also a technique used by
anorexics
• similar risk profile as
anorexic - though loss of selfcontrol a factor
• used by athletes to lose
weight fast
• treatment complicated
• multidisciplinary approach
most effective
UNDERWEIGHT
• regular meals
• increase caloric
intake,
particularly
complex CHO
• regular physical
activity - relate
to self-esteem
AMERICAN COLLEGE OF SPORTS
MEDICINE GUIDELINES FOR
WEIGHT CONTROL
• AVOID PROLONGED
FASTING
• MILD CALORIC
RESTRICTION - MAX
RESTRICTION OF 5001000/day
• EXERCISE
• MAINTAIN NUTRITION
• BEHAVIOR
MODIFICATION
Hunger, Appetite, Satiety
• Hypothalamus
Regulates
Appetite
• Monitors Levels of
Nutrients in Blood
• Obese eating cues:
Frequency and
Intensity increase!
Adaptive Thermogenesis
• Large Amounts of food
• No Weight Gain
• Metabolic Activity
Adjusts
• Brown Fat Cells
control the
thermogenesis
response
Satiety
• Feeling of Full
• Nutritional Needs
• Obese vs. Non-Obese
Why We Eat…….
Hunger
Appetite
• Inborn
• Physiological
• Need
• Learned Response
• Emotional//Psychological
• Craving