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Medicine LibreTexts

4: Body Composition

  • Page ID
    151523
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    By Scott Flynn

    Learning Objectives
    • What is body composition?
    • How does body composition affect a person’s health?
    • What are the health risks and costs associated with overweight and obesity?
    • What is the significance of body fat distribution?
    • What is Body Mass Index (BMI) and why is it important?

    • 4.1: Body Weight versus Body Composition
      This page discusses gender differences in exercise motivations, noting that American females exercise mainly for weight control, while males aim for muscle tone, reflecting societal beauty standards. This focus can foster unhealthy behaviors, including eating disorders.
    • 4.2: Diseases Associated with Excessive Body Fat
      This page outlines the health risks associated with excessive body fat, emphasizing links to Type II Diabetes, hypertension, various cancers, stroke, cardiovascular disease, metabolic syndrome, respiratory issues like sleep apnea, musculoskeletal disorders, liver and gallbladder diseases, and mental health concerns. It also offers resources for further exploration of obesity-related diseases.
    • 4.3: How Much Fat is Needed?
      This page emphasizes the vital role of fat in nutrition, highlighting essential and nonessential fat types and their health implications. It discusses the risks of excess body fat, including classifications of overweight and obesity, and their negative impacts on physical and mental health, as well as lifespan.
    • 4.4: Body Fat Distribution
      This page emphasizes the crucial role of body composition in evaluating health risks and developing tailored exercise and nutrition plans. It details the distinction between subcutaneous and visceral fat, the latter being a significant risk factor for type II diabetes and cardiovascular issues. The page also discusses body shapes (android vs.
    • 4.5: Body Mass Index
      This page examines body mass index (BMI) as a prevalent health risk assessment tool using weight and height. While it provides a general estimate of healthy weight, it is criticized for failing to differentiate between fat mass and fat-free mass, especially for athletes and seniors. BMI also does not consider age and gender variations. Nonetheless, it is still valuable for monitoring weight changes and forecasting health outcomes in the general population.
    • 4.6: How to Measure Body Composition
      This page explores various body composition estimation methods, crucial for health risk assessment. It reviews Hydrostatic Weighing (accurate but impractical), Dual Energy X-Ray Absorptiometry (DEXA, considered the gold standard), Air Displacement (less accurate than underwater weighing), Bio-electrical Impedance Analysis (BIA, influenced by hydration, affordable), and Skinfold Analysis (simple and portable, moderate accuracy).
    • 4.7: Weighing in on the U.S.
      This page addresses the epidemic rise of overweight and obesity in the U.S., revealing that 70.7% of adults are overweight and 37.9% are obese, with substantial increases since 1962. Additionally, it highlights that 17.4% of children and 20.6% of adolescents are impacted. The page also critiques BMI as a potential underestimator of true obesity levels, suggesting that the actual prevalence may be even higher than reported.
    • 4.8: What Can Be Done?
      This page discusses the significance of evaluating body composition and fat distribution to identify health risks linked to body fat. It recommends using a combination of measures like BMI, waist circumference, and body fat percentage for a thorough health assessment. The content points out the dangers associated with both excessive and insufficient body fat and advocates for a holistic approach to weight management, focusing on proper nutrition and lifestyle monitoring.


    This page titled 4: Body Composition is shared under a CC BY-NC-ND 4.0 license and was authored, remixed, and/or curated by Scott Flynn, Jonathan Howard, Lisa Jellum, and Althea Moser (GALILEO Open Learning Materials) via source content that was edited to the style and standards of the LibreTexts platform.