Understanding 7 Understanding Body Composition

PowerPoint ® Lecture Outlines 7 Understanding Body Composition

• 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.

• 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.

• Percent Body Fat The percentage of your total weight that is fat tissue (weight of fat divided by total body weight).

• Essential Fat 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.

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.

• Calculate your body mass index (BMI).

• BMI: A common measurement to assess disease risks.

• Understand the limits of BMI: Scores do not differentiate between fat and lean body mass.

• Measure your body circumference: Use waist and hip measurements to determine your waist-to-hip ratio (WHR).

Identify your body’s patterns of fat distribution.

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)

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.

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.

• 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.

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.