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Presentation Package for Concepts of Physical Fitness 12e. Section V: Concept 15: Body Composition. Created by: Gregory J. Welk Iowa State University. Trends in the Prevalence of Obesity in the U.S. 1991-98,. Click to see progression of trends over time. % Obese.
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Presentation Package for Concepts of Physical Fitness 12e Section V: Concept 15: Body Composition Created by: Gregory J. Welk Iowa State University
Trends in the Prevalence of Obesity in the U.S. 1991-98, Click to see progression oftrends over time % Obese Mokdad et al. JAMA 1999; 282:1519 Web15-1 Concepts of Physical Fitness 12e
Health Risks Associated with Being Overweight • Coronary heart disease • Hypertension • Hypercholesterolemia • Diabetes There are also health risks associated with being too thin! Concepts of Physical Fitness 12e
Definitions of Overweight:(Based on ht /wt tables) • Moderately Overweight • 20% over desirable body weight • Severely overweight • 40% over desirable body weight Burton, Foster, Hirsch, and Van Itallie, Health implications of obesity: An NIH consensus development conference. Int J. Obesity, 9, 155-169, 1985. Problem: Ht/Wt tables do not take muscles mass into account Concepts of Physical Fitness 12e
Click for info on BMI Definitions of Overweight (Based on BMI values) • BMI accounts for differences in frame size better than height weight tables. BMI = Wt (kg) / Ht2 (m) • Standards: • Overweight: > 25 • Obesity: > 30 • Severe obesity > 40 Problem: BMI does not take muscles mass into account Web15-1 for moreinformation on standards Concepts of Physical Fitness 12e
Click for calculations of ideal wt based on % fat Levels of Body Fatness Men Women Essential fat 5% 10% Borderline5-9% 10-16% Good fitness - health 10-20% 17-28% Marginal fitness 21-25% 29-35% Overfatness > 25% > 35% Concepts of Physical Fitness 12e
Click for more info on fatdeposition Male (apple) Female (pear) Higher health risk Lower health risk Regional Fat Deposition • Abdominal body fat poses greater health risks than fat stored in other areas • Males store more fat centrally and have increased health risks associated with body fatness Concepts of Physical Fitness 12e
Body Composition Assessment Techniques • Underwater weighing • Technological assessments • Skinfold technique • Anthropometric measurements Concepts of Physical Fitness 12e
Click for more info Underwater Weighing Technique Body fat provides more bouyancy so a fatter person weighs less (on a relative basis) than a lean person Web15-2 for info on underwater weighing Concepts of Physical Fitness 12e
Technological Assessments of Body Composition Click to seemore info on all techniques • Dual X-Ray Impedance Analysis (DXA) • Bioelectric impedance • Infra-red spectroscopy • Ultrasound • Imaging techniques (DEXA, MRI) Click individualtechnique to see more detail Web15-2 for info on DXA Concepts of Physical Fitness 12e
Skinfold Technique Layers of subcutaneous fat are measured at different sites of body to estimate total body fat levels Cross sectional view Concepts of Physical Fitness 12e
Benefits of Skinfold Technique • Fairly accurate • Easy to perform • Inexpensive Concepts of Physical Fitness 12e
Lab 15a info Common Skinfold Sites Jackson and Pollack Males Female Chest Triceps Abdomen Supraillium Thigh Thigh 7 site procedure Chest Axilla Tricep Subscapular Abdomen Supraillium Thigh Alternative Sites (Males & Females) Tricep Abdomen Calf Validation statistics on 3 site test: - r = .97 with 7 site procedure - R2 = .80 with underwater weighing Web15-3 Concepts of Physical Fitness 12e
Lab 15binfo Anthropometric Measurements • Body Mass Index (BMI) • Waist to Hip Ratio (WHR) • Circumference measures More info More info More info Concepts of Physical Fitness 12e
Body Composition AssessmentImplications of Results • Values are estimates (+/- 2-3% at best) • Values are personal and confidential Proper uses of results: - Serve as baseline data for repeated testing - Provide motivation for goal setting - Provide awareness about health risks Concepts of Physical Fitness 12e
HT (in.) WT (lb.) BMI 72 150 21 72 180 25 72 190 26 72 200 28 Sample BMI Values Return to presentation This chart reveals how BMI values change for a hypothetical 6 foot tall person of different body weights See Web15-05 for BMI calculators Concepts of Physical Fitness 12e
Body Composition (2 compartment model) • Fat • Lean Body Mass (LBM): (bones, muscles, tissues, organs) Sample calculation: 70kg person with 20% body fat: • Lean tissue: 70 kg x .80 = 56 kg • Fat tissue: 70 kg x .20 = 14 kg Concepts of Physical Fitness 12e
See sample calculation Wt. - (Wt. x %Fat / 100) Desired Weight = (1 - desired %Fat) Calculating Desired Body Weight Current Lean weight Wt. - (fat weight) Desired Weight = = Desired Lean % (1 - desired %Fat) Concepts of Physical Fitness 12e
Current weight = 200 Current body fat% = 20% Desired body fat% = 15% DesiredWeight = 200 - (200 x .20) (1 - .15) DesiredWeight = 160 200 - 40 = 188 = .85 (.85) Calculating Desired Body Weight (Example) Return to presentation Concepts of Physical Fitness 12e
Regional Fat DepositionVisceral Fat • Visceral body fat poses greater health risks because this fat is more labile and has greater access to the circulation. • The accumulation of visceral body fat is typical of the android (male) fat pattern • males: visceral accounts for 10-35% of total fat • females: visceral accounts for 8-13%of total fat Concepts of Physical Fitness 12e
Abdominal Body FatRelationships with CHD Risks • Abdominal obesity predicts CHD risk independent of BMI, smoking, cholesterol and hypertension(Kannel et al., J. Clin Epid., 44, 183-190, 1991). • Abdominal obesity predicts CHD risk independent of total body fatness.(Larsson et al. ,Appetite, 13, 37-44, 1989). • Abdominal obesity statisticallly accounts for difference in CHD rates between men and women (Larsson et al., Am. J. Epi., 135: 266-273, 1992). Concepts of Physical Fitness 12e
Abdominal Body FatRelationships with other risk factors • Abdominal obesity is strongly influenced by genetics - similar gain among twins (r=.72). (Bouchard, NEJM, 322, 1477-1482, 1990). • Abdominal obesity is greater in smokers than non-smokers due to the presence of androgens (Barrett-Conner, Ann. Int. Med. 111, 783-787, 1989). • Abdominal body fat is preferentially lost during a physical activity program(Kohrt, J. Gerontology, 47: M99-M105, 1992) Concepts of Physical Fitness 12e
Waist to Hip Ratio (WHR) Return to presentation • Waist to Hip Ratio is an effective way to examine regional fat distribution. WOMEN HEALTH RISK MEN High Risk > 1.0 > .85 Moderate Risk .90 -1.0 .80-.85 Low Risk < .90 < .80 Concepts of Physical Fitness 12e
Obesity Trends* Among U.S. Adults Proportion of Obese Adults by StateBRFSS (*BMI 30, or ~ 30 lbs overweight for 5’4” woman) Slides from the CDC Concepts of Physical Fitness 12e
No Data <10% 10%-14% 15-19% 20% Source: Mokdad AH. Obesity Trends* Among U.S. AdultsBRFSS, 1990 (*BMI 30, or ~ 30 lbs overweight for 5’4” woman) Concepts of Physical Fitness 12e
No Data <10% 10%-14% 15-19% 20% (*BMI 30, or ~ 30 lbs overweight for 5’4” woman) Source: Mokdad AH. Obesity Trends* Among U.S. AdultsBRFSS, 1991 Concepts of Physical Fitness 12e
No Data <10% 10%-14% 15-19% 20% (*BMI 30, or ~ 30 lbs overweight for 5’4” woman) Source: Mokdad AH. Obesity Trends* Among U.S. AdultsBRFSS, 1992 Concepts of Physical Fitness 12e
No Data <10% 10%-14% 15-19% 20% (*BMI 30, or ~ 30 lbs overweight for 5’4” woman) Source: Mokdad AH. Obesity Trends* Among U.S. AdultsBRFSS, 1993 Concepts of Physical Fitness 12e
No Data <10% 10%-14% 15-19% 20% (*BMI 30, or ~ 30 lbs overweight for 5’4” woman) Source: Mokdad AH. Obesity Trends* Among U.S. AdultsBRFSS, 1994 Concepts of Physical Fitness 12e
No Data <10% 10%-14% 15-19% 20% (*BMI 30, or ~ 30 lbs overweight for 5’4” woman) Source: Mokdad AH. Obesity Trends* Among U.S. AdultsBRFSS, 1995 Concepts of Physical Fitness 12e
No Data <10% 10%-14% 15-19% 20% (*BMI 30, or ~ 30 lbs overweight for 5’4” woman) Source: Mokdad AH. Obesity Trends* Among U.S. AdultsBRFSS, 1996 Concepts of Physical Fitness 12e
No Data <10% 10%-14% 15-19% 20% (*BMI 30, or ~ 30 lbs overweight for 5’4” woman) Source: Mokdad AH. Obesity Trends* Among U.S. AdultsBRFSS, 1997 Concepts of Physical Fitness 12e
No Data <10% 10%-14% 15-19% 20% (*BMI 30, or ~ 30 lbs overweight for 5’4” woman) Source: Mokdad AH. Obesity Trends* Among U.S. AdultsBRFSS, 1998 Concepts of Physical Fitness 12e
No Data <10% 10%-14% 15-19% 20% (*BMI 30, or ~ 30 lbs overweight for 5’4” woman) Source: Mokdad AH. Obesity Trends* Among U.S. AdultsBRFSS, 1999 Concepts of Physical Fitness 12e
No Data <10% 10%-14% 15-19% 20% (*BMI 30, or ~ 30 lbs overweight for 5’4” woman) Source: Mokdad AH. Obesity Trends* Among U.S. AdultsBRFSS, 2000 Concepts of Physical Fitness 12e
1991 1995 2000 Obesity Trends* Among U.S. Adults BRFSS, 1991, 1995 and 2000 Source: Mokdad A H, et al. J Am Med Assoc1999;28216, 2001;286:10. Concepts of Physical Fitness 12e
Web Links • BRFSS Interactive Web Page http://www.cdc.gov/nccdphp/brfss/ Concepts of Physical Fitness 12e