Power Point Lecture Outlines 7 Understanding Body Composition

Power. Point® Lecture Outlines 7 Understanding Body Composition Copyright © 2009 Pearson Education, Inc.

Objectives • Define body composition. • Explain why the assessment of body size, shape, and composition is useful. • Explain how to perform assessments of body size, shape, and composition. • Evaluate your personal body weight, size, shape, and composition. • Set goals for a healthy body fat percentage. • Plan for regular monitoring of your body weight, size, shape, and composition. Copyright © 2009 Pearson Education, Inc.

Body Composition Concepts • Body Composition The relative amounts of lean tissue and fat tissue in your body. • Lean Body Mass Your body’s total amount of lean/fat-free tissue (muscles, bones, skin, organs, body fluids). • Fat Mass Body mass made up of fat tissue. Copyright © 2009 Pearson Education, Inc.

Body Composition Concepts • Percent Body Fat The percentage of your total weight that is fat tissue (weight of fat divided by total body weight). • Essential Fat necessary for normal body functioning (including in the brain, muscles, nerves, lungs, heart, and digestive and reproductive systems). • Storage Fat Nonessential fat stored in tissue near the body’s surface. Copyright © 2009 Pearson Education, Inc.

Why Body Size, Shape, and Composition Matter Knowing body composition can help assess health risks. • More people are now overweight or obese. • Estimates of body composition provide useful information for determining disease risks. Evaluating body size and shape can motivate healthy behavior change. • Changes in body size and shape can be more useful measures of progress than body weight. • Overweight vs. Overfat Copyright © 2009 Pearson Education, Inc.

Body Composition for Men and Women For typical 20 -24 year old men and women Copyright © 2009 Pearson Education, Inc.

How to Evaluate Body Size and Shape • Calculate your body mass index (BMI) using your height and weight. • BMI: A common measurement to assess disease risks. • Understand the limits of BMI: • Scores do not differentiate between fat and lean body mass – limited benefit for individuals. • Good for large populations used in research Copyright © 2009 Pearson Education, Inc.

Estimating BMI Copyright © 2009 Pearson Education, Inc.

BMI and Health Copyright © 2009 Pearson Education, Inc.

Health Risks Associated with Body Size and Shape • Measure your body circumference: Use waist and hip measurements to determine your waist-to-hip ratio (WHR). (Lab 7. 2) Android Pattern • “Apple” shaped • Excess body fat on upper body and trunk • Associated with greater disease risk Gynoid Pattern • “Pear” shaped • Excess fat mainly on lower body (hips and thighs) Copyright © 2009 Pearson Education, Inc.

Android and Gynoid Body Fat Distribution Copyright © 2009 Pearson Education, Inc.

Assessing Body Composition Skinfold Measurements • Use calipers to measure skinfold thickness. • Accurate assessments require experience and practice. Dual-Energy X-Ray Absorptiometry (DXA) • The “gold standard” for assessing body composition. • Uses low-radiation x-rays to distinguish body components. Hydrostatic Weighing (Underwater Weighing) • Requires an equipped facility. • Measures water displacement/buoyancy Copyright © 2009 Pearson Education, Inc.

Assessing Body Composition Air Displacement (Bod Pod) • Measures total body air displacement. • Used with other measures for a full assessment. Bioelectrical Impedance Analysis (BIA) • Measures resistance of tissues to electrical currents. • Accuracy depends on machine quality and participant cooperation. Estimates from Circumferences or BMI • Provide rough estimates. • Can provide a starting point for weight management. Copyright © 2009 Pearson Education, Inc.

Bioelectrical Impedance Analysis (BIA) Copyright © 2009 Pearson Education, Inc.

Evaluating or Changing Your Body Composition • Determine if your percent body fat is within a healthy range. • Set reasonable goals. • Follow a well-designed exercise and nutrition plan. • Regularly monitor your body size, shape, and composition. Copyright © 2009 Pearson Education, Inc.

Copyright © 2009 Pearson Education, Inc.

Evaluating or Changing Your Body Composition Weekly • Assess your body shape and size (use indicators such as a mirror and the fit of your clothes). • Assess your weight. Monthly or Every Few Months • Measure your body’s circumferences. • Measure your BMI. • Measure your percent body fat. Copyright © 2009 Pearson Education, Inc.