Body Composition

storage fat

-Major fat depot consisting of fat accumulation in adipose tissue (adipocytes) -Consists of VISCERAL and SUBCUTANEOUS fat -Men and women have similar quantities of storage fat (12% for men, 15% for women) -TOTAL FAT = Essential Fat + Storage Fat

white adipose cells

-Most fat is stored in _____ ____ ____ which contain one large fat droplet -Insulator and cushion for organs

brown adipose cells

-These adipose cells contain many small fat droplets -More blood vessels -Large number of iron-containing mitochondria (generates more heat) -Plays trivial role in weight maintenance

Bioelectrical Impedance Analysis

-A small current flowing through body -Current passes easier (LESS RESISTANCE) through hydrated fat-free tissue rather than fat or bone tissue (HIGH RESISTANCE) -Measures weight, body fat%, lean tissue, fat mass, total body water -Factors affecting measurement outcomes: time of day & hydration levels

fat mass, fat-free, relative body fat

Key Terminology _____ ______ (FM) -The ABSOLUTE amount of body fat -Includes all extractable lipids from adipose and other tissue ____-_____ mass (FFM) -LIPID-FREE chemicals and tissue= -Water, muscle, bone, connective tissue, organs -FFM= Body mass - Fat mass _____ _____ _____ percentage (%BF) -FM expressed as a percentage of TOTAL body mass (TBM)

bod pod

-Air displacement plethysmography to assess body volume -Similar to underwater weighing, except uses air instead of water -Thoracic gas volume difficult to measure

skinfold thickness

-Anthropometric measure -Cheap, and easy to transport -Many sites & Many equations -Technician error -Measure each site 3 times

underwater weighing

-Measures body density (mass/volume) to determine body fat -Based on the fact that fat tissue is LESS DENSE than lean tissue -Fat tissue = 0.9 g/cm3 -Lean tissue = 1.1 g/cm3 -The closer the body density to 1.1 g/cm3, the leaner the person is

Dual Energy X-ray Absorptiometry

-Sends two x-ray sources through the body, and the amount of x-ray attenuation (LOSS OF INTENSITY of flux through a medium) is measured -Creates an image based on ATTENUATION values -Measures BMD and content -Measures region percent fat, fat mass, and bone-free lean body mass (muscle and organ) -Error ~ ±3%

essential fat

-consists of fat in the heart, lungs, liver, spleen, kidneys, intestines, muscles, CNS, bone marrow -normal physiologic function requires this fat -Men ~3% & Women ~12%

adipose tissue

-specialized for storage of energy in the form of triglycerides (fat) -Comprised of 83% fat, 2% protein, 15% water -Comprised mainly of ADIPOCYTES, makes up ~20% of body weight in men and ~28% of body weight in women -______ cells = adipocytes = fat cells -30-50 billion fat cells in an adult of normal weight

triglyceride, hypertrophy, exceeds, hyperplasia, larger

Adipocytes -Adipocytes can increase in size 10x to store more _______ (Increase in size = ______) -Once adipocytes reach capacity, new adipocytes form, usually occurs once total body fat ____ ~30 kg (Increase in number = ______) -A newly overweight individual may have the SAME number of adipocytes as a normal weight individual, but the cells are _______ -An OBESE person, however, may have as many as 75-80 billion fat cells

decreased, connective fibers, cellulite

Adipocytes -Once fat cells are created, they CANNOT be naturally removed -The size can only be _______ -An ENLARGED fat cell can cause bulging between _____ ______ that keeps skin attached to the body -Creates a dimply effect labeled as ______

skeletal muscle, excess fat

Body Composition Variability -Ratio of _______ _______ to fat varies -Highly trained male athlete 5:1 (50% muscle, 10% fat) -Highly trained female athlete 3:1 (45% muscle, 15% fat) -In the rest of the population reduced muscle and _____ ____ is COMMON -Men <2:1(<35% muscle, >25% fat) & Women <1:1 (<30% muscle, >35% fat)

levels, fat cells

Body Fat Regulation -Body fat _____ are regulated by many factors: sex hormones, local factors & genetics -Fat is continually flowing in and out of ____ ____ at all times regardless of the nutritional state

nutritional status, physical fitness

Significance of Body Composition -Indicator of ______ _______: Diseases or abnormal conditions & Differences among individuals or groups -Related to HEALTH and overall well being: Increased fat mass = Increased disease risk, Low bone density & Decreased muscle mass= decreased ADL's -Affects ______ _______ and performance -Affected by physical activity and EXERCISE

body mass index, anthropometry, body density, densitometry

Terminology -_____ _____ ____ (BMI): body mass divided by height squared (kg/m2) -_______: standardized techniques to quantify or predict body size, weight, proportion, and shape(Limb circumferences, height, weight) -_____ _____: body mass per unit of body volume -_____ _____: archimedes' principle of water displacement to estimate body density; used in hydrostatic weighing (underwater weighing)

body composition

The amounts of fat and nonfat (lean or fat-free) tissues in an individual

outside, underwater

Underwater Weighing -Calculated by determining weight ______ (in air) and weight ______ -Downfall with UWW is it's an expensive piece of equipment

direct/gold, indirect

_____/______ standard -Chemical analysis of the body -Human cadaver _______ assessment -Estimation of body composition -Hydrostatic weighing -Simple anthropometric measurements

waist curcumference

______ ______ can be used to determine health risk because abdominal obesity (visceral fat) increases health risk

Waist-to-hip ratio (WHR)

________-______-_______ can be used as a simple method for determining body fat distribution