Presentation Package for Concepts of Fitness & Wellness 9e

1. Presentation Package for Concepts of Fitness & Wellness 9e Section V Nutrition and Body Composition

2. Possessing an optimal amount of body fat contributes to health and wellness. Concept 13 Body Composition

3. Online Learning Center Presentation Overview • Body composition measures • Health risks • Obesity trends • Physical activity-body composition relationship Discussion Activity

4. Understanding & InterpretingBody Composition Measures • Component of health-related fitness & metabolic fitness • Standards have been established for healthy levels of body fatness & BMI(see next slide) • Assessing body weight too frequently can result in making false assumptions about body composition changes

5. Health-Related Body Fatness Standards

6. Methods Used to Assess Body Composition • DXA • Underwater Weighing • Bod Pod • Skinfold technique • Other

7. Dual-Energy Absorptiometry(DXA or DEXA) • “Gold Standard” - highly accurate • Criterion measure that has been used to validate other, more practical measures of body composition • Provides whole body measurements as well as in different parts of the body

8. Click for more info Underwater Weighing • A person is weighed in air and under water • The difference in weight is used to assess body fatness • Body fat provides more buoyancy, so a fatter person weighs less (on a relative basis) than a lean person

9. Bod Pod • Uses the same principles as underwater weighing, but relies on air displacement to assess body composition • Acceptable alternative to underwater weighing • Particularly useful for special populations (e.g., obese older people, the physically challenged)

10. Skinfold Technique Layers of subcutaneous fat are measured at different sites of body to estimate total body fat levels Cross sectional view

11. Benefits of Skinfold Technique • Skinfold measurements are the preferred, practical method of assessing body fatness • Fairly accurate • Easy to perform • Inexpensive Lab 13a info

12. Common Skinfold Sites 7 site procedure Chest Axilla Tricep Subscapular Abdomen Supraillium Thigh Jackson and Pollock Males Female Chest Triceps Abdomen Supraillium Thigh 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

13. Research Quality Skinfold Calipers Harpenden Calipers Lange Calipers

14. Other Body Composition Assessments • Bioelectrical Impedance • Infra-Red Spectroscopy • Ultrasound • Imaging Techniques Click to seemore info on all techniques

15. Anthropometric Measurements Lab 13b info • Body Mass Index (BMI) • Waist to Hip Ratio (WHR) • Circumference measures More info More info More info

16. 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

17. Photo: Creative Commons Flickr

18. Health Risks Associated with Being Overweight • Coronary heart disease • Hypertension • Hypercholesterolemia • Diabetes • Premature death • Physical fitness provides protection from the health risks of obesity There are also health risks associated with being too thin!

19. Click for more info on fat deposition 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

20. Health Risks Associated withExcessively Low Body Fatness • Anorexia Nervosa • Binge-eating • Bulimia (bingeing and purging) • Anorexia Athletica • Female Athlete Triad • Muscle Dysmorphia (males) • Fear of Obesity • Purging Disorder

21. The Origin of Fatness Lab 13c info • Obesity is a multifactorial disease that is influenced by both genetics and the environment • Body weight is regulated and maintained through complex regulatory processes • Set-point • Fatness early in life leads to adult fatness • Changes in basal metabolic rate can be the cause of obesity • “Creeping Obesity” (see next slide)

22. Obesity Trends* Among U.S. AdultsBRFSS,1990, 1999, 2008 (*BMI 30, or about 30 lbs. overweight for 5’4” person) 1999 1990 2008 No Data <10% 10%–14% 15%–19% 20%–24% 25%–29% ≥30%

23. CREEPING OBESITY Actually more like 5-9 pounds “Freshman 15”

24. Relationship Between PA & Body Composition • Combination of regularPAanddietarymodification is the mosteffectivemeans of losingbodyfat • PA that can be sustained for relatively long periods is considered the most effective for losing body fat • Strength training can be effective in maintaining a desirable body composition • Regular PA is critical for building and maintaining bone health

25. PhysicalActivity Daily moderate PA; 3-6 days/wk vigorous PA Slow, low-intensity that results in ≤1-2 lbs/wk of fat loss 30-60 minutes 200-300 min/wk Diet Consistently & daily Modest caloric restriction Moderate meals Target Zone- Body Fat Reduction F I T

26. Summary • Obesity is prevalent in society • Need to find ways to maintain optimal body composition • Use assessments to determine body composition and make the necessary healthy changes to physical activity and diet End of presentation

27. Online Learning Center Supplemental Information Lab Information Detail on BMI calculations Body comp technique details Discussion Activity

28. Lab 13a InformationEvaluating Body Composition - Skinfolds • The purpose of this lab is to evaluate body composition with the skinfold assessment • Comparisons will be made between different procedures and testers to learn about the accuracy of the tests

29. Lab 13a InformationSkinfold Technique Return to presentation • Measurement Technique: • Mark site with marker • Pinch fold above and below mark with left and right hand • Measure fold with caliper using the right hand • Scoring Procedure: • Sum skinfolds from the 3 sites • Look up percent body fat valuefrom chart in the book

30. Lab 13b InformationEvaluating Body Composition – Height, Weight, and Circumference Measures • The purpose of this lab is to evaluate body composition with some anthropometric assessments • Height/Weight • Body Mass Index • Waist to Hip Ratio

31. Lab 13b Information BMI Measurement Technique Return to presentation • Convert weight to kilograms (2.2 kg/lb.) • Convert height to meters (.0254 m/in) • Square the height in meters • Divide the squared height value into the weight value BMI = Wt (kg) / Ht2 (m)

32. Lab 13b Information WHR Measurement Technique Return to presentation • Waist:Measure at the "natural waist" (smallest circumference) or at the level of the umbilicus • Hip:Measure at the maximum circumference of the buttocks Divide the hip measurement into the waist measurement to obtain the WHR

33. Waist to Hip Ratio(WHR) Return to presentation • Waist to Hip Ratio is an effective way to examine regional fat distribution HEALTH RISK MEN WOMEN High Risk > 1.0 > .85 Moderate Risk .90 -1.0 .80-.85 Low Risk < .90 < .80

34. 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

35. Return to presentation 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 muscle mass into account

36. Lab 13c InformationDetermining Your Daily Energy Expenditure Return to presentation • Estimate your basal metabolism • First determine the #of minutes you sleep • Monitor your activity expenditure for 1 day • Record the number of 5-, 15-, and 30-minute blocks of time you perform each of the different types of physical activities • Be sure to distinguish between moderate (Mod) and vigorous (Vig) intensity in your logging • Discuss your daily caloric expenditure

37. 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

38. 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).

39. Abdominal Body FatRelationships with other risk factors Return to presentation • 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)

40. Underwater WeighingMeasurement Issues Return to presentation • Based on body density calculations • Density of lean tissue = 1.1 g/cc • Density of fat tissue = .9 g/cc • Sources of error • Residual lung volume • Bone density varies by age, ethnicity and activity level • General conclusions • Gold standard measure (1-2% error) • Impractical for most applications

41. Bioelectric ImpedanceMeasurement Issues Return to presentation • Based on resistance to current flow • Lean tissue has more water - less resistance • Fat tissue has less water - more resistance • Sources of error • Temperature • Hydration status • General conclusions • Overestimates lean / underestimates obese • Practical, but expensive, measure for general population

42. Infrared SpectroscopyMeasurement Issues Return to presentation • Based on differential absorbance rates • Lean tissue has a different energy absorption and reflectance pattern than fat tissue • Sources of error • Validity of absorbance readings is questionable! • General findings • NOT a valid measure!

43. UltrasoundMeasurement Issues Return to presentation • Based on reflection of sound • Fat content increases the time is required for sound to reflect off of bone and muscle. • Sources of error • Representative sites for measurement • Measurement error • General conclusions • Highly accurate measure of body fat - especially for obese • Expensive and not practical for most applications

44. Imaging TechniquesMeasurement Issues Return to presentation • Based on imaging of body tissues • Based on cross sectional area measures calculated at different levels of the body • Sources of error • Representative sites for measurement • Measurement error • General conclusions • Very precise measure of body composition • Expensive and not practical measure for most uses

45. Return to presentation CircumferencesMeasurement Technique • Based on circumference measures • sample prediction equation:% fat = - 47.372 + (.579 x abdomen) + (.252 x hip) + (.214 x iliac) + (.356 x BW) • Sources of error • Location of sites • Inability to distinguish fat and muscle • General conclusions • Provides reasonable estimate of body fat • Not as accurate as skinfold and takes same time

46. Return to presentation Discussion Activity What are the biggest influences on your level of body fatness?