Presentation Package for Concepts of Physical Fitness 12e Section V: Concept 15: Body Composition Created by: Gregory J. Welk Iowa State University

2Concepts of Physical Fitness 12e Trends in the Prevalence of Obesity in the U.S , % Obese Mokdad et al. JAMA 1999; 282:1519 Web15-1 Click to see progression of trends over time

3Concepts of Physical Fitness 12e Health Risks Associated with Being Overweight Coronary heart disease Coronary heart disease Hypertension Hypertension Hypercholesterolemia Hypercholesterolemia Diabetes Diabetes There are also health risks associated with being too thin!

4Concepts of Physical Fitness 12e Definitions of Overweight: ( Based on ht /wt tables) Moderately Overweight Moderately Overweight –20% over desirable body weight Severely overweight 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, , Problem: Ht/Wt tables do not take muscles mass into account

5Concepts of Physical Fitness 12e Definitions of Overweight (Based on BMI values) BMI accounts for differences in frame size better than height weight tables. BMI = Wt (kg) / Ht 2 (m) BMI accounts for differences in frame size better than height weight tables. BMI = Wt (kg) / Ht 2 (m) Standards: Standards: –Overweight:> 25 –Obesity:> 30 –Severe obesity> 40 Problem: BMI does not take muscles mass into account Click for info on BMI Web15-1 for more information on standards

6Concepts of Physical Fitness 12e Levels of Body Fatness MenWomen MenWomen Essential fat 5% 10% Borderline 5-9% 10-16% Good fitness - health 10-20%17-28% Marginal fitness21-25%29-35% Overfatness > 25% > 35% Click for calculations of ideal wt based on % fat

7Concepts of Physical Fitness 12e Regional Fat Deposition Abdominal body fat poses greater health risks than fat stored in other areas 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 Males store more fat centrally and have increased health risks associated with body fatness Higher health risk Lower health risk Male (apple) Female (pear) Click for more info on fat deposition

8Concepts of Physical Fitness 12e Body Composition Assessment Techniques Underwater weighing Underwater weighing Technological assessments Technological assessments Skinfold technique Skinfold technique Anthropometric measurements Anthropometric measurements

9Concepts of Physical Fitness 12e Underwater Weighing Technique Click for more info Web15-2 for info on underwater weighing Body fat provides more bouyancy so a fatter person weighs less (on a relative basis) than a lean person

10Concepts of Physical Fitness 12e Technological Assessments of Body Composition Dual X-Ray Impedance Analysis (DXA) Dual X-Ray Impedance Analysis (DXA) Bioelectric impedance Bioelectric impedance Bioelectric impedance Bioelectric impedance Infra-red spectroscopy Infra-red spectroscopy Infra-red spectroscopy Infra-red spectroscopy Ultrasound Ultrasound Ultrasound Imaging techniques Imaging techniques (DEXA, MRI) Imaging techniques Imaging techniques (DEXA, MRI) Click to see more info on all techniques Click individual technique to see more detail Web15-2 for info on DXA

11Concepts 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

12Concepts of Physical Fitness 12e Benefits of Skinfold Technique Fairly accurate Fairly accurate Easy to perform Easy to perform Inexpensive Inexpensive

13Concepts of Physical Fitness 12e Common Skinfold Sites 7 site procedure Chest Axilla Tricep Subscapular Abdomen Supraillium Thigh Jackson and Pollack MalesFemale ChestTriceps AbdomenSuprailliumThigh Lab 15a info Validation statistics on 3 site test: - r =.97 with 7 site procedure - R 2 =.80 with underwater weighing Alternative Sites (Males & Females) Tricep Abdomen Calf Web15-3

14Concepts of Physical Fitness 12e Anthropometric Measurements Body Mass Index (BMI) Body Mass Index (BMI) Waist to Hip Ratio (WHR) Waist to Hip Ratio (WHR) Circumference measures Circumference measures More info Lab 15b info

15Concepts of Physical Fitness 12e Body Composition Assessment Implications of Results Values are estimates (+/- 2-3% at best) Values are estimates (+/- 2-3% at best) Values are personal and confidential 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

16Concepts of Physical Fitness 12e Sample BMI Values HT (in.)WT (lb.)BMI This chart reveals how BMI values change for a hypothetical 6 foot tall person of different body weights Return to presentation See Web for BMI calculators

17Concepts of Physical Fitness 12e Body Composition (2 compartment model) Fat Fat Lean Body Mass (LBM): (bones, muscles, tissues, organs) Lean Body Mass (LBM): (bones, muscles, tissues, organs) 70kg person with 20% body fat: Lean tissue: 70 kg x.80 = 56 kg Fat tissue:70 kg x.20 = 14 kg Sample calculation:

18Concepts of Physical Fitness 12e Calculating Desired Body Weight Desired Weight = Wt. - (fat weight) (1 - desired %Fat) See sample calculation Desired Weight = Wt. - (Wt. x %Fat / 100) (1 - desired %Fat) Current Lean weight Desired Lean % =

19Concepts of Physical Fitness 12e Calculating Desired Body Weight (Example) Current weight = 200 Current body fat% = 20% Desired body fat% = 15% Desired Weight = (200 x.20) (1 -.15) Desired Weight = (.85) = = 188 Return to presentation

20Concepts of Physical Fitness 12e Regional Fat Deposition Visceral Fat Visceral body fat poses greater health risks because this fat is more labile and has greater access to the circulation. 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 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

21Concepts of Physical Fitness 12e Abdominal Body Fat Relationships with CHD Risks Abdominal obesity predicts CHD risk independent of BMI, smoking, cholesterol and hypertension (Kannel et al., J. Clin Epid., 44, , 1991). Abdominal obesity predicts CHD risk independent of BMI, smoking, cholesterol and hypertension (Kannel et al., J. Clin Epid., 44, , 1991). Abdominal obesity predicts CHD risk independent of total body fatness. (Larsson et al.,Appetite, 13, 37-44, 1989). 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: , 1992). Abdominal obesity statisticallly accounts for difference in CHD rates between men and women (Larsson et al., Am. J. Epi., 135: , 1992).

22Concepts of Physical Fitness 12e Abdominal Body Fat Relationships with other risk factors Abdominal obesity is strongly influenced by genetics - similar gain among twins (r=.72). (Bouchard, NEJM, 322, , 1990). Abdominal obesity is strongly influenced by genetics - similar gain among twins (r=.72). (Bouchard, NEJM, 322, , 1990). Abdominal obesity is greater in smokers than non- smokers due to the presence of androgens (Barrett-Conner, Ann. Int. Med. 111, , 1989). Abdominal obesity is greater in smokers than non- smokers due to the presence of androgens (Barrett-Conner, Ann. Int. Med. 111, , 1989). Abdominal body fat is preferentially lost during a physical activity program (Kohrt, J. Gerontology, 47: M99-M105, 1992) Abdominal body fat is preferentially lost during a physical activity program (Kohrt, J. Gerontology, 47: M99-M105, 1992)

23Concepts of Physical Fitness 12e WOMEN MEN High Risk Moderate Risk Low Risk > 1.0 > HEALTH RISK <.90 <.80 Return to presentation Waist to Hip Ratio (WHR) Waist to Hip Ratio is an effective way to examine regional fat distribution. Waist to Hip Ratio is an effective way to examine regional fat distribution.

24Concepts of Physical Fitness 12e Obesity Trends* Among U.S. Adults Proportion of Obese Adults by State BRFSS (*BMI 30, or ~ 30 lbs overweight for 54 woman) Slides from the CDC

25Concepts of Physical Fitness 12e Obesity Trends* Among U.S. Adults BRFSS, 1990 (*BMI 30, or ~ 30 lbs overweight for 54 woman) No Data <10% 10%-14% 15-19% 20% Source: Mokdad AH.

26Concepts of Physical Fitness 12e Obesity Trends* Among U.S. Adults BRFSS, 1991 (*BMI 30, or ~ 30 lbs overweight for 54 woman) No Data <10% 10%-14% 15-19% 20% Source: Mokdad AH.

27Concepts of Physical Fitness 12e Obesity Trends* Among U.S. Adults BRFSS, 1992 (*BMI 30, or ~ 30 lbs overweight for 54 woman) No Data <10% 10%-14% 15-19% 20% Source: Mokdad AH.

28Concepts of Physical Fitness 12e Obesity Trends* Among U.S. Adults BRFSS, 1993 (*BMI 30, or ~ 30 lbs overweight for 54 woman) No Data <10% 10%-14% 15-19% 20% Source: Mokdad AH.

29Concepts of Physical Fitness 12e Obesity Trends* Among U.S. Adults BRFSS, 1994 (*BMI 30, or ~ 30 lbs overweight for 54 woman) No Data <10% 10%-14% 15-19% 20% Source: Mokdad AH.

30Concepts of Physical Fitness 12e Obesity Trends* Among U.S. Adults BRFSS, 1995 (*BMI 30, or ~ 30 lbs overweight for 54 woman) No Data <10% 10%-14% 15-19% 20% Source: Mokdad AH.

31Concepts of Physical Fitness 12e Obesity Trends* Among U.S. Adults BRFSS, 1996 (*BMI 30, or ~ 30 lbs overweight for 54 woman) No Data <10% 10%-14% 15-19% 20% Source: Mokdad AH.

32Concepts of Physical Fitness 12e Obesity Trends* Among U.S. Adults BRFSS, 1997 (*BMI 30, or ~ 30 lbs overweight for 54 woman) No Data <10% 10%-14% 15-19% 20% Source: Mokdad AH.

33Concepts of Physical Fitness 12e Obesity Trends* Among U.S. Adults BRFSS, 1998 (*BMI 30, or ~ 30 lbs overweight for 54 woman) No Data <10% 10%-14% 15-19% 20% Source: Mokdad AH.

34Concepts of Physical Fitness 12e Obesity Trends* Among U.S. Adults BRFSS, 1999 (*BMI 30, or ~ 30 lbs overweight for 54 woman) No Data <10% 10%-14% 15-19% 20% Source: Mokdad AH.

35Concepts of Physical Fitness 12e Obesity Trends* Among U.S. Adults BRFSS, 2000 (*BMI 30, or ~ 30 lbs overweight for 54 woman) No Data <10% 10%-14% 15-19% 20% Source: Mokdad AH.

36Concepts of Physical Fitness 12e Obesity Trends* Among U.S. Adults BRFSS, 1991, 1995 and Source: Mokdad A H, et al. J Am Med Assoc 1999;28216, 2001;286:10.

37Concepts of Physical Fitness 12e Web Links BRFSS Interactive Web Page BRFSS Interactive Web Page