Body weight and composition for health and sport

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Body weight and composition for health and sport

• Williams, 8th edition
• Chapter 10

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• Body composition assessment - Table 10.1 on p.
  367
• Anthropometrics body segment girths to predict
  body fat
• Skin folds Using calipers (figure 10.4 p. 369)
• Bioelectrical impedance (BIA) figure 10.2 p. 368
• Body plethysmography (figure 10.3 on p. 368)
• Computed tomography (CT)
• Dual X-ray absorptiometry (DEXA)
• Near infrared interactance (NIR)
• Magnetic resonance imaging (MRI)
• Underwater weighing (Hydro-densiometry)

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What is the composition of the human body?

• Chemical elements
• Recall that Carbon, Hydrogen, Oxygen, and
  Nitrogen in various combinations make up protein,
  CHO and fat and compose about 96 of the human
  body
• Remaining 4 consists of minerals (calcium and
  phosphorous in the bones also iron, potassium,
  sodium, magnesium, chloride distributed
  throughout the body)

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Composition of human body, cont.

• Scientists divide body into four components
• a. Total body fat
• b. Fat-free mass
• c. Bone mineral
• d. Body water
• Each component has a different density
  (mass/volume)
• a. Water, 1.0 or 1 g/ml
• b. Bone, 1.3-1.4
• c. Fat-free tissue, 1.1
• d. Fat, 0.9

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Condensing body composition into two components

• A. Total body fat
• 1. Essential fat
• a. Adult males, 3 of body weight
• b. Adult females, 12-15 of body weight
• 2. Storage fat varies considerably
• a. Found around body organs
• b. Fifty percent is subcutaneous fat
• c. Visceral fat is associated with ? health
  risk

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Two components of body comp, cont.

• B. Fat-free or lean body mass
• 1. Components
• a. Protein
• b. Water
• c. Minerals
• d. Glycogen
• 2. Bone mineral
• a. 50 water and 50 solid matter
• b. Total bone weight may be 12-15 of total
  body weight
• c. Mineral content is only 3-4 of total
  body weight

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Body composition assessment

• 1. Anthropometry
• Circumferences abdominal, hips, iliac (between
  hips and waist) and waist
• Estimating body-fat distribution waist to hip
  ratio (should be lt 0.9 for men and lt 0.8 for
  women)
• Skin folds abdomen, biceps, chest, subscapular
  (under shoulder blade in back), suprailiac
  (between hip and navel), and triceps
• Jaws of calipers should be opened at right angles
  to fold. Tips should come into contact with
  skinfold about 1 cm. below point where skinfold
  was raised.
• Record in millimeters. Note 3 measurements
  should be taken at each site.
• Percent body fat is based on triceps (mm)
  biceps (mm) subscapular (mm) suprailiac (mm)
  compared to a standard table.

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Body comp assessment, cont

• 2. BIA disposable surface electrodes are placed
  on hand, wrist, foot, and ankle.
• Current sent through proximal electrodes to
  distal electrodes, measuring resistance.
• Theory greater resistance or impedance ?
  greater body fat
• Variables in equation height, weight, sex, and
  age
• Not accurate in significantly overweight and
  underweight individuals.

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Bioelectrical Impedance (BIA) Source
http//www.uky.edu/Education/KHP/Body_comp/Equipme
ntPhotos.htm
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Body comp assessment, cont

• 3. Body plethysmography (Body Pod) individual
  sits inside chamber measures air displacement
  and calculates body density
• 4.Computed tomography (CT) X-Ray scanning also
  used to measure bone mass

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Body comp assessment, cont

• 5. Dual X-ray absorptiometry (DEXA) X-ray
  technique used to separate fat, fat-free tissue,
  and bone mineral
• 6. NIR (near infrared) uses light absorption and
  reflection
• 7. Densiometry (underwater and hydrostatic
  weighing) measures H20 displacement since fat
  is less dense and bone and muscle are more dense,
  a given weight of fat will displace a larger
  volume of water and have a more buoyant effect.

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Dual X-ray absorptiometry Source
http//www.bcm.edu/cnrc/images/4_stories/Dexaadult
.jpg
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Ideal weight?

• Accurate balance beam scales or digital scales
  best for obtaining accurate body weight.
• Breadth of elbow best for measuring frame size
  can use calipers or estimate using metric ruler.
  Need to place thumb and index finger on outside
  of each epicondyle and measure distance between
  them with ruler. (Procedure completed in class)
• Percent ideal weight Current weight
  reference weight x 100
• Current weight

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Ideal weight cont.

• Example 175 is weight
• 140 is reference weight
• 175 -140 20 above reference weight
• 175

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Body Mass Index (BMI)

• BMI Weight (kg)
• Height (m2)
• Also BMI Body wt in pounds X 705
• (Height in inches)2
• BMI uses total body weight, not estimates of fat
  and lean mass.
• See Method A in Appendix D for sample calculation

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How to interpret BMI -See Federal obesity
guidelines National Institutes of Health pub
98-4083)

• Underweight BMI lt 18.5
• Normal 18.5-24.9
• Overweight BMI gt 25-29.9
• Obesity BMI gt 30
• Obesity
• Level I 30-34.9
• Level II 35-39.9
• Level III gt 40

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Federal obesity guidelines, cont.

• Anyone gt age 18 with BMI gt 25 is at risk
• Treatment is recommended in overweight or obese
  individuals with 2 or more risk factors (table
  10.3).

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Other considerations

• Fat free mass body weight (kg) fat weight
  (kg)
• Fat weight in kg
• Body weight (kg) x percent fat
• 100
• Total body water almost all of bodys water is
  in fat-free mass.
• Essential (meaning the minimum) fat for women
  is 12 and for men 3-4

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Percent body fat ranges

• Minimal levels of total fat for health
• a. 5-10 percent for males
• b. 15-18 percent for females
• Average levels
• a. 15-18 percent for males
• b. 22-25 percent for females
• Obesity levels
• a. 25 percent for males
• b. 30 percent for females

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How body normally controls its own weight

• Appetite regulation/Physiological factors
• 1. Hypothalamus in brain (appestat controls
  hunger and satiety)
• 2. Feedback from neural centers outside brain
  (sight, smell, appetite)
• 3. Metabolism, stomach fullness, blood glucose
  level, body temp (as it rises, appetite
  decreases)
• 4. Hormone actions (insulin, thyroxine, leptin)

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Resting energy expenditure (REE) changes may be
involved in regulation of body weight

• Brown fat releases E without ATP production. In
  rats, ? levels of brown fat ? ? obesity
• White fat tissue and muscle tissue thermogenesis
  without ATP production associated with high
  caloric intake, especially dietary fat.
• Hormones
• A. Thyroid hormones may be involved in
  stimulation of brown fat
• B. Epinephrine increases energy expenditure
• C. Decrease in hormonal activity may depress
  energy metabolism

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Leptin and energy expenditure

• Leptin protein made by fat cells
• Obesity gene (ob) is expressed in the fat cells
  and codes for leptin (a protein produced by fat
  cells under direction of ob gene ? associated
  with ? appetite and ? E expenditure)
• Leptin appears to promote negative balance by ?
  appetite, and ? E expenditure
• Deficient "ob gene" (expressed in fat cells and
  code for leptin) ? obesity
• Leptin activity ? efficiency in obese people 

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Feedback control of energy intake and expenditure

• Short-term feedback
• a. Stomach expansion
• b. Body stores of carbohydrates, proteins, and
  fat regulated on short-term basis
• Long-term, set point theory
• a. Hypothalamus contains redundant systems to
  regulate energy balance
• b. Activity-stat may function to increase or
  decrease physical activity
• c. Theory may explain why many people maintain
  normal weight throughout life

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Other factors causing obesity

• Genetics
• 1. Obesity genes may maintain an unhealthy
  set-point
• 2. A predisposition to craving sweet, high-fat
  foods
• 3. Impaired hormonal functions (e.g. Insulin
  and blood sugar control)
• 4. A lower REE
• 5. A decreased TEF

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Genetic factors, cont.

• Inability of nutrients or hormones in blood to
  suppress appetite control center (?)
• Enhanced metabolic efficiency in storing fat?
• A greater number of fat cells
• Low rates of fat oxidation, low plasma leptin
  concentrations
• Decreased levels of human growth hormone
• Lower levels of spontaneous physical activity
  during the day
• Lower levels of energy expenditure during light
  exercise

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Environmental factors

• Excess Calories, particularly dietary fat
• A chronic high-fat diet leads to leptin
  resistance in hypothalamus, physiological changes
  in body
• Physical inactivity
• Drinking alcohol
• Smoking cessation

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How is fat deposited in body

• Early theories on fat deposition
• a. Hyperplasia
• b. Hypertrophy
• Fat cell numbers may continue to increase as
  long as excess energy intake occurs
• Genetic predisposition to inherit gt number of
  fat cells, facilitating development of obesity
• Individuals without this genetic predisposition
  may still become obese with positive energy
  balance stored as fat

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Health conditions associated with excess body fat

• Coronary heart disease (CHD)
• Hypertension
• Diabetes
• Hypercholesterolemia
• Obesity does not increase mortality unless it
  adversely effects several factors
• a. Blood pressure
• b. Glucose tolerance
• c. Serum cholesterol levels
• d. Physical fitness

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Location of body fat appears to be more important
than overall obesity

• Android-type obesity (apple shaped)
• Greater health risk than obesity itself
• a. Hyperinsulinemia
• b. Insulin resistance
• c. Impaired glucose tolerance
• d. Hypertriglyceridemia
• e. Increased LDL and decreased HDL
  cholesterol
• f. More common in males

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Location of body fat, cont.

• Gynoid-type obesity (pear shaped)
• 1. Health risks are not as great
• 2. More resistant to change (fat is not as
  readily mobilized from hips and buttocks as it
  is from abdomen)
• Both android and gynoid obesity are assessed by
  measuring waist circumference

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Health risks in youth

• Obese adolescents greater risk for chronic
  diseases in adulthood
• Obesity contributes more greatly to
  social-emotional problems at this time than
  during adulthood
• Psychological problems
• Rejection
• Negative self-image
• Low self-esteem
• Another contributing factor to development of
  psychological problems may be adverse effect of
  excessive body fat on physical fitness and
  athletic performance

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Treatment and prevention of health risks

• 30 of adult population are carrying too much
  body fat for optimal health
• 25 percent of adolescents and children in U.S.
  are carrying too much body fat for optimal health
• Prevalence of overweight is increasing
• Treatment of obesity helps reduce risk factors
  associated with chronic diseases
• Exercise is particularly important
• Prevention is key

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Health problems result from excessive weight loss

• Dangerous techniques used to achieve rapid weight
  loss (NOT recommended)
• Starvation
• Self-induced vomiting
• The use of diet pills
• The use of laxatives and/or diuretics

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General effects of excessive rapid and long-term
weight losses on health

• Dehydration techniques problems
• 1. Heat illnesses
• 2. Increased loss of potassium from body
• a. Electrolyte imbalances
• b. Disturbed neurological function
• c. Possible cardiac arrest
• 3. Disturbed kidney function

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Weight loss drugs FDA recommends only short term
use combined with sound stress management and
diet program
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Weight loss drugs various effects

• Appetite suppressants
• Increase energy expenditure
• Block intestinal absorption of dietary fat
• NOTE Lost weight is regained upon cessation of
  drug use if life-style is not changed
• Adverse side effects of long-term drug use
• (a) Tremor
• (b) Seizures
• (c) Psychoses
• (d) Heart arrhythmias
• (e) Pulmonary hypertension
• (f) Habituation
• (g) Addiction
• (h) Death

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Complications VLCD

• May lead to a decreased TEF
• May decrease REE
• May lead to weight cycling
• Not satisfying
• Seldom result in any long-term weight loss

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Health problems severe weight restriction over
long time period with children

• Studies on adolescent female gymnasts and
  swimmers showed that growth velocity of gymnasts
  was lower than the swimmers
• Theorized that growth rate was impaired by two
  factors
• a. Heavy training
• b. Metabolic effects of dieting

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Eating disorders

• Anorexia nervosa diagnostic criteria
• 1. Refusal to maintain body weight over a
  minimal normal weight for age and height
• 2. Intense fear of gaining weight or becoming
  fat, even though underweight
• 3. Disturbance in the way one's weight or shape
  is perceived
• 4. Amenorrhea in females
• Typically found in women lt age 25

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Medical consequences Anorexia

• Hormonal imbalances
• Anemia
• Decreased heart muscle mass
• Heart beat arrhythmias attributed to electrolyte
  imbalances
• Death

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Bulimia nervosa diagnostic criteria

• Recurrent episodes of binge eating, at least 2
  per week for 3 months
• Lack of control over eating during binge
• Regular use of self-induced vomiting, laxatives,
  diuretics, fasting, or excessive exercise to
  control body weight
• Persistent concern with body weight and body
  shape
• NOTE Bulimia is more common than anorexia

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Adverse health effects of bulimia

• Erosion of tooth enamel (from acidity of stomach
  acid that is regurgitated during vomiting)
• Tears in the esophagus
• Aspiration pneumonia (inappropriate passage of
  food, water, stomach acid, or vomit into the
  lungs resulting in pneumonia)
• Heart failure (low potassium)
• NOTE Prevalence of eating disorders in general
  population is only 1-3, but number of people who
  experience eating problems without meeting strict
  criteria is much higher

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Eating problems associated with sports

• Loss of excess body weight may cause drop in
  weight class, improve appearance and/or
  biomechanics, and enhance potential for success
  in some sports
• a. Wrestling
• b. Gymnastics
• c. Ballet
• d. Figure skating
• e. Diving
• f. Distance running
• g. Lightweight football
• h. Lightweight rowing

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Anorexia athletica, criteria

• Excessive fear of becoming obese
• Restriction of caloric intake
• Weight loss
• No explaining medical disorder
• Gastrointestinal complaints
• PLUS one or more of these related criteria
• (a) Disturbed body image
• (b) Compulsive exercising
• (c) Binge eating
• (d) Use of purging methods
• (e) Delayed puberty
• (f) In women menstrual dysfunction

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Anorexia athletica, cont.

• 20-40 female athletes may exhibit criteria for
  this disorder
• 50-74 have been reported for
• (1) Gymnastics
• (2) Distance running
• (3) Competitive bodybuilding
• What begins on short-term basis may develop into
  long-term medical problems

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Female athlete triad
Source http//www.hkeducationcenter.com/courses/O
EC_Previews/hf-ft303_preview/images/fig_03.gif
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Problems associated with female athlete triad

• Athletic amenorrhea related to excessive loss of
  body fat
• Decreased fat levels ? decreased estrogen
  production ? impaired bone tissue formation ?
  loss of bone mass
• Exercise does not appear to counteract adverse
  effects associated with decreased estrogen levels
  in athletic amenorrhea
• Amenorrheic athletes more prone to
  musculoskeletal injuries
• Resting metabolic rate may be reduced

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Treatment of athletic amenorrhea

• Exercise somewhat less
• Increase calories and amounts of animal protein
• Increase protein and calcium from milk and other
  dairy products
• Nutritional supplements may be used to improve
  energy balance and nutritional status
• Prevention of eating disorders is key

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What effect does excess body weight have on
physical performance?

• Extra body weight might prove to be an advantage
  in some sports
• Football
• Ice hockey
• Sumo wrestling
• NOTE Increases in body weight for sports
  competition should maximize muscle mass and
  minimize body-fat gains

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Sports for which excess body weight may be
disadvantageous

• High jump
• Long jump
• Ballet
• Gymnastics
• Sprinting
• Long-distance running

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General guidelines, body fat for sports
performance

• 5-10 body fat
• Male sprinter
• Long-distance runners
• Wrestlers
• Gymnasts
• Basketball players
• Soccer players
• Swimmers
• Bodybuilders
• Football backs

• 11-15 body fat
• Baseball players
• Football linemen
• Tennis player
• Weight lifters

lt 15gymnasts and distance runners 15-20 most
female athletes 25 strength-type athletes
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Excess weight loss ? physical performance

• Ultimate effect upon performance dependent upon
  technique used and time over which weight is lost
• Events characterized by power, strength, and
  speed may not be adversely affected by short-term
  dehydration but will be by longer term
• Aerobic and anaerobic endurance events are likely
  to deteriorate
• Short-term starvation involving rapid weight loss
  impairs physical performance if blood-glucose and
  muscle-glycogen levels are lowered substantially
• Anaerobic and aerobic endurance performance will
  suffer if dependent upon muscle glycogen or
  normal blood-glucose levels
• Long-term semi-starvation leads to significant
  losses of lean muscle tissue and decreased
  performance in almost all fitness components