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2. Fundamental Concepts 2e. . . Health Risks Associated with Being Overweight. Coronary heart diseaseHypertensionHypercholesterolemiaDiabetes. There are also health risks associated with being too thin!. 3. Fundamental Concepts 2e. . . Body Composition (2 compartment model). FatLean Body Mass
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1. Body Composition&Body ImageHPE 1000-01 Wellness This lecture will cover the subject of body composition. Students will learn about the different assessment techniques and how body composition influences health.This lecture will cover the subject of body composition. Students will learn about the different assessment techniques and how body composition influences health.
2. 2 Fundamental Concepts 2e Health Risks Associated with Being Overweight Coronary heart disease
Hypertension
Hypercholesterolemia
Diabetes Many health problems are associated with excess levels of body fatness
Obesity is considered to be a secondary risk factor for coronary heart disease mainly because the effect of body fatness is manifested in other risk factors. These data show the relative risk of other risks if you are overfat (data from NHANES II data cited in VanIttallie (1992):
Hypertension (RR = 2.9x)
Hypercholesterolemia (RR = 1.5x
Diabetes (RR = 2.9x)
VanIttallie, T. B. (1992) Body Weight, Morbidity, and Longevity. IN: Bjorntorp, P. & Brodoff, B.N. (Eds.) Obesity. Lippincott Co.., Philadelphia.
Many health problems are associated with excess levels of body fatness
Obesity is considered to be a secondary risk factor for coronary heart disease mainly because the effect of body fatness is manifested in other risk factors. These data show the relative risk of other risks if you are overfat (data from NHANES II data cited in VanIttallie (1992):
Hypertension (RR = 2.9x)
Hypercholesterolemia (RR = 1.5x
Diabetes (RR = 2.9x)
VanIttallie, T. B. (1992) Body Weight, Morbidity, and Longevity. IN: Bjorntorp, P. & Brodoff, B.N. (Eds.) Obesity. Lippincott Co.., Philadelphia.
3. 3 Fundamental Concepts 2e Body Composition (2 compartment model) Fat
Lean Body Mass (LBM): (bones, muscles, tissues, organs) Discuss the 2 compartment model of body composition.
Fat Mass (FM)
Lean Body Mass (LBM) or Fat Free Mass (FFM)
Discuss the 2 compartment model of body composition.
Fat Mass (FM)
Lean Body Mass (LBM) or Fat Free Mass (FFM)
4. Fundamental Concepts 2e 4 Regional Fat Deposition (WHR) The site of fat deposition is also an important consideration for health. Fat stored in the abdominal region presents more risk than fat stored in the lower or upper extremities
The site of fat deposition is also an important consideration for health. Fat stored in the abdominal region presents more risk than fat stored in the lower or upper extremities
5. 5 Fundamental Concepts 2e 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 statistically accounts for the difference in CHD rates between men and women (Larsson et al., Am. J. Epi., 135: 266-273, 1992). There are many studies that document the health risks associated with abdominal obesity.There are many studies that document the health risks associated with abdominal obesity.
6. 6 Fundamental Concepts 2e 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) These are some additional studies that document the health risks of abdominal obesityThese are some additional studies that document the health risks of abdominal obesity
7. 7 Fundamental Concepts 2e Body Composition Estimation BMI
Circumference Measures
Skinfolds
Bioelectric impedance
Underwater Weighing
Imaging techniques (DEXA, MRI) Other body fat assessment techniques are available.
Bioelectric Impedance:
Electrical conduction is different in different tissues. Muscle has water and is a good conduction. Fat has less water and is a poor conductor. It tends to overestimate %fat in lean people and underestimate %fat in fat people.
Infra Red
Absorption of light is different in different tissues.
Ultrasound
Sound absorbence is different in different tissues (muscle: sounds bounces off; fat: sounds pass through)
Imaging Techniques (DEXA, MRI)
Considered to be highly accurate but expensive
Chemical measures (3 methyl histidine - waste product of muscle - corr with LBM
Other body fat assessment techniques are available.
Bioelectric Impedance:
Electrical conduction is different in different tissues. Muscle has water and is a good conduction. Fat has less water and is a poor conductor. It tends to overestimate %fat in lean people and underestimate %fat in fat people.
Infra Red
Absorption of light is different in different tissues.
Ultrasound
Sound absorbence is different in different tissues (muscle: sounds bounces off; fat: sounds pass through)
Imaging Techniques (DEXA, MRI)
Considered to be highly accurate but expensive
Chemical measures (3 methyl histidine - waste product of muscle - corr with LBM
8. Fundamental Concepts 2e 8 BMI’s for Adults
9. 9 Fundamental Concepts 2e Underwater Weighing Technique The gold standard measurement for body composition assessment is currently underwater weighing. It is based on the fact that muscle is more dense than fat
- muscle is like a rock (it sinks)
- fat is like styrofoam (it floats)
By weighing a person underwater you can estimate body density. The procedure is based on Archimedes Principle which states that the buoyant force is equal to the weight of the volume of water that is displaced. Fat because it is less dense occupies a larger volume which gives it a larger buoyant force
NOTE: The story of Archimedes and the gold crown is effective for explanation (muscle = gold and fat = silver)
The gold standard measurement for body composition assessment is currently underwater weighing. It is based on the fact that muscle is more dense than fat
- muscle is like a rock (it sinks)
- fat is like styrofoam (it floats)
By weighing a person underwater you can estimate body density. The procedure is based on Archimedes Principle which states that the buoyant force is equal to the weight of the volume of water that is displaced. Fat because it is less dense occupies a larger volume which gives it a larger buoyant force
NOTE: The story of Archimedes and the gold crown is effective for explanation (muscle = gold and fat = silver)
10. 10 Fundamental Concepts 2e 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 Body Fat estimates from calipers must be interpreted correctly. It is important to keep the following factors in mind:
1. The estimates have 2-3% error so the value that results is not "exact". It is more important to look at trends over time.
2.Values serve as baseline for goal setting. You need to
know where you are to set objective goals. Book has a chart to calculate desired weight based on current level and desired level (formula available from instructor).
3. Values are individual. People should not compare values with other people or be embarrassed about their numbers. Each person is different and it may not be possible for all people to achieve the ideal percent body fat.
Body Fat estimates from calipers must be interpreted correctly. It is important to keep the following factors in mind:
1. The estimates have 2-3% error so the value that results is not "exact". It is more important to look at trends over time.
2.Values serve as baseline for goal setting. You need to
know where you are to set objective goals. Book has a chart to calculate desired weight based on current level and desired level (formula available from instructor).
3. Values are individual. People should not compare values with other people or be embarrassed about their numbers. Each person is different and it may not be possible for all people to achieve the ideal percent body fat.
11. 11 Fundamental Concepts 2e Calculating Desired Body Weight (Example) This slide shows the calculations used to calculate desired body weight based on current body fat percentage and desired body fat percentage
A chart in the book simplifies this calculation
This slide shows the calculations used to calculate desired body weight based on current body fat percentage and desired body fat percentage
A chart in the book simplifies this calculation