BODY COMPOSITION ASSESSMENT Flashcards
Describe the body composition of muscle, fat and bone in males vs females.
Body composition:
Males- 45% Muscle, 3% Essential fat, 12% non-essential fat (storage), 15% bone, 25% other
Females-36% muscle, 12% essential fat, 15% non-essential (storage) fat, 12% bone, and 25% other.
men have more muscle and bone
women have more fat
what is the purpose of determining body frame size? How is it defined and measured?
Body frame size- a way to evaluate “normalcy” of body weight with standardized charts
-Defined by a combination of Stature and Bony widths since it relates to FAT-FREE Body mass and NOT body fat.
Measurements:
-STATURE measured in cm
-Biacromial diameter (Cm); the distance between the most lateral projections of acromial processes
-Bitrochanteric diameter (cm): the distance between the most lateral projection of the greater trochanters.
what are the limitations of height weight tables?
limitations of Height-Weight Tables:
- Use unvalidated estimates of body frame size
- Developed from data derived primarily from White populations
- Specific focus on mortality data that may not reflect obesity-related comorbidities
- provide NO assessment of body composition
Differentiate between the terms overweight, overeat, and obese. Which of these is the most important to watch out for?
Overweight- a body weight that exceeds some Average for stature and perhaps age, usually by some standard deviation unit or percentage
-frequently accompanies an increase in body fat, but NOT always (some free-fat mass)
-Overfatness: when body fat exceeds an age and or gender appropriate average by a predetermined amount
-Obesity- the overfat condition that accompanies a constellation of comorbidities.
obesity is most important when considering one’s health
Describe the purpose of Body Mass index (BMI) including the equation. What happens if BMI increases? Is there a BMI that classifies children or adolescents?
Body Mass Index:
- Derived from body mass and stature
- Used to assess “normalcy” for body weight
- BMI= body mass (Kg) divided by stature (m2)
- As BMI increases, so does the RISK for certain diseases
- No absolute BMI standard exists to classify children and adolescents as Overweight and obese.
Describe the benefits of BMI, weight classifications
BMI and weight classifications are a quick way of focusing on risks of diseases for people
BMI- good screening tool to identify high risk patients
but BMI is NOT absolute.
Heart disease, stroke ,hypertension arthritis, gallstones and diabetes are diseases that people who are overweight, obese and moderately morbidly are at risk for.
Hypertension, gallstones and diabetes- all three classifications increased dramatically
Describe the relationship between obese individuals and mortality.
Obese individuals did NOT live as long as those who had a BMI of desirable value (whether smoker or non-smoker) Hence being obese is a risk factor for mortality Desirable BMI (18.5-24.9) Overweight BMI (25-29.9) Obese BMI (> than or equal to 30)
Explain the relationship between waist circumference, body mass between different age groups who are running.
Which group has the lowest waist circumference and body mass.
What happens to waist circumference in individuals each year?
What happens to out metabolic rate as we age?
Which group has lowest waist circumference and body mass?
Experiment with People of different ages running and maintaining a certain distance
overtime ,the people are running same amount and waist circumference increases each year.
waist circumference- measurement taken around the abdomen at the level of umbilicus (belly button)
people increase their weight by 2 pounds each year as one ages
(10 years, gained 20 pounds)
-As we age our basal metabolic rate DECREASES
Waist circumference and body mass increase in every single group
those who ran the furthest have Lowest body mass and waist circumference , but they are more prone to injury overtime.
How does BMI levels at a young age determine possible risks for health as one ages.
if BMI is 24 at age 10, there is 95% chance of being overweight
whereas if BMI is at 14 at age 10, you have 5% chance of being overweight.
*Having high BMI at a younger age, increases the chances (guaranteed) of being overweight when you are in your 20s and will continue as you age.
Describe how BMI at young age affects hypertension.
hypertension risk increases when you have higher BMI at 18 years old.
even decreasing BMI after 18 years, did not change hypertension risk
being a kid and not having a high BMI and hence no hypertension risk before 18 years old is important for preventing hypertension risk in future (as you age)
18 years old is when you have adipose tissue
How old do you get adipose tissue? What happens
Adipose tissue undergoes hypertrophy (increase in size of cells)
18 years old is when you have adipose tissue
if at a young age, you have a high BMI, you already have a lot of adipose tissue.
It is hard to get rid of adipose tissue (only so much you can lose)
can get rid of adipose tissue- through cool sculpting and liposuction
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What are the limitations for BMI?
BMI Limitations:
- Current classification for overweight assumes that the relationship between BMI and percentage body fat remains independent of age, gender. ethnicity, and race.
- fails to consider the body’s proportional composition or body fat distribution
- Factors other than excess body fat, such as bone, muscle mass and increased plasma volume induced by exercise training affect the numerator of BMI equation
- The possibility of misclassifying someone as overweight pertains particularly to some athletes.
Describe the major components models used for human body composition. differentiate between reference man and reference woman
human body composition
Component model:
-Three: Water, protein, fat
-Four,: Water, Protein, bone mineral and fat
-Four comment model is most ideal as bone mineral contributes to fat free mass
Reference man and reference woman:
-divides body mass into lean body mass, muscle, and bone, with total body fat subdivided into storage and essential fat
-reference man is taller and heavier, the skeleton weighs more and has a larger muscle mass and Lower body fat content than the reference woman
Differentiate between Essential fat and Non-essential (storage) fat. can you have 0% body fat
Essential fat:
-fat in heart, lungs, liver, spleen, kidneys, intestines, muscles and lipid-rich tissues of central nervous system, bone marrow are dependent on essential fat
-Normal physiologic functioning requires this fat
Storage fat (non-essential)
-fat primarily in Adipose tissue
-83% pure fat, 2% protein and 15% water
Visceral fat (Dad bod)
One cannot have 0 % body fat because it is dangerous (need certain amount of body fat for all the organs )
Differentiate between lean body mass and fat-free mass. Also describe these portions in man and woman
Lean body mass: includes non-sex-specific essential fat equivalent to approximately 3% of body mass
Fat-free mass: Body mass devoid of all extractable fat
reference manL 12% storage fat and 3% of essential fat
reference woman: 15% storage fat and 12% of essential fat
describe the composition of male and female for total body mass, lean body mass, muscle, bone and Toal body fat.
reference man:
total body mass: 70 kg
lean body mass: 88.1% of body mass
muscle - 44.7%
bone- 15%
total body fat -15% (12% storage, 3% of essential
reference woman:
total body mass: 57 kg
Lean body mass: 85% of body mass
Muscle: 36%
Bone-12%
Total body fat: 27% (15% essential; 12% storage
essential body fat - 12%
, storage fat 15%, lean body massLWomen have a higher body fat composition than men.
lean body mass in male and female are almost the same amount.
Describe the common techniques used to asses body composition
Common Techniques to Assess Body Composition:
- Direct measurement by chemical analysis of the animal carcass or or human cadaver (not a practical way, but best way to do it)
- One technique dissolves the body in a chemical solution to determine its mixture of fat and fat-free components
- Another physically dissects fat, fat-free adipose tissue, muscle and bone
Describe the indirect estimation that occurs when assessing body techniques
Techniques to assess body composition:
Indirect Estimation
-Hydrostatic weighing using Archimedes principle (displacement of water)
-Skinfold thickness and girth measurements
-X-ray and magnetic resonance imaging
-Total body electrical conductivity or Bioimpedance
-Near-infrared interactance
-Ultrasound
-computed tomography
-Air plethysmography
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Explain how you compute the percentage of body fat for anyone. Also include the assumptions allow that
Computing percentage of Body fat
-An equation that incorporates whole-body density estimates the body’s fat percentage
-SIRI equation:
-Percentage body fat= 495 divided by bone density) - 450
-Assumes:
-two component model of body composition
-each of these densities remains relatively constant among individuals
-Densities of the. lean tissue components of bone and muscle, remained the same among individiuals
not the best method for body fat
What are the limitations of density assumptions? How was the Siri equation modified?
Limitations of Density Assumptions;
-Density values for fat-free an fat tissue compartments represent averages for young and middle-aged adults, though they vary among individuals and groups
-FFM (fat-free mass) density is HIGHER for Blacks and hispanics
-Racial différences also exist among adolescents
-Overestimate FFM (free fatty mass) and Underestimates percentage body fat in blacks and Hispanics
-Modification of Siri equation computes percentage body fat from body density for blacks:
percentage body fat= (437.4) divided by body density) - 392.8
Discuss the equations used to calculate fat mass and fat-free body mass
Fat mass= body mass x (% fat/100)
Fat free body mass= body mass - fat mass
What is the purpose of skin fold measurement sites? Where are these sites located?
Skin fold measurement- a way of measuring fat free mass
Skin fold measurement sites:
1. TRICEPS- vertical fold at posterior midline of right upper arm, halfway between tip of shoulder and tip of elbow
2. SUBSCAPULAR: Oblique fold, below right scapula’s lower tip
3. ILIAC: slightly oblique fold, just above the right hipbone (crest of ileum); the fold follows the natural diagonal line
4. ABDOMINAL Vertical fold 1 inch to right of umbilicus
5. THIGH: vertical fold at the midline of right thigh, 2/3 distance from middle of patella to hip
6. CHEST Diagonal fold on anterior axillary line
7. BICEPS- vertical fold at right upper arm’s midline
Which areas of the body are girth measurements located?
Girth measurements:
- ABDOMEN: 1 inch above the umbilicus
- BUTTOCKS : maximum profusion which heels together
- THIGH: Upper thigh, just below the buttocks
- UPPER ARM (biceps): Arm straight and extended in front of the body; measurement taken at midpoint between n the shoulder and elbow
- FOREARM- maximum girth with arm extended in front of body
- CALF: wildest girth midway between ankle and bone
Discuss the process of bioelectrical impedance analysis and how it is used, its purpose and requirements.
Bioelectrical Impedance Analysis:
-Small alternating current flowing between two electrodes passes more rapidly through Hydrated fat free tissues and Extracellular water than through fat or bone tissues because of lower electrical resistance of fat-free tissues
Impedance to electric current flow is calculated:
frequency of current goes though tissue that is Less resistant (fat-free tissues)
R= VI, where R= resistance, V= Volume and I = current
-this representers a Non-invasive, Safe, relatively Easy, and reliable means to assess total body water
-Requires standardized conditions: Electrode placement , body position, hydration status, plasma osmolarity, and sodium concentration, skin temperature, recent physical activity, and previous food and beverage intake
What is the average body fat (percentage ) in men vs women. what change is seen in body fat as we age?
Average Body fat;
Young adult men: 12-15% (total fat)
Young adult women: 25-28%
-No systemic evaluation exists for body composition of the general population to warrant establishing norms or precise recommended values for body composition
-The general trend indicates a tendency for percentage body fat to steadily INCREASES with advancing age (even when exercising at older age)
Describe how you are able to calculate your goal body weight
Goal body weight (Kg)= Fat-free body mass divided by (1.00- desired %fat)
fat mass= body weight x percent body fat
fat-free body mass= body weight - fat mass
Goal weight = fat free body mass % (1.0- 0.15) =
ex: 85.6 kg(goal weight) and 91 kg is body weight.
Describe the obesity prevalence and how many individuals are affected in America and world wide.
Obesity Prevalence:
- 140 milion Americans are either overweight or obese
- Overweight occurrence is higher in women and minority groups
- 34% of adult population classify as Obese
- Worldwide 310 million are obese and 775 million are overweight
- OBESITY is the second leading cause of preventable deaths in United States
- Annual cost estimated at $140 billion
What is the second leading cause of preventable death in U.S.?
OBESITY
Describe the level of obesity that occurs in children. How have obesity rates changed over the years? How does this affect children as they grow up?
Obesity in children
-In the last 30 years, childhood obesity has Tripled among children ages 6 to 11 to more than 15%
-rate have doubled for ages 2-5 (>10%) and 12-19 (15%)
-Overweight children and adolescents, regardless of final body weight, exhibit higher risk of illnesses as adults than adolescents of normal weight
-Overall, 32% of children are overweight or obese
-16% obese
11% extremely obese
What percent of children are overweight or obese? What about adults? Explain why women tend to be more overweight compared to men
2-19 17% of children are overweight
women tend to be more overweight as we age
-adults
-35-36% of all men and women are obese or overweight in U.S.
As women age, women gain weight due to menopause.
How many children and adults are overweight and obese?
How has obesity and BMI values changed in Europe?
12.5 million children are overweight or obese
77.5 million of adults age 20 and older are overweight or obese
obesity and BMI also increasing in Europe (especially in Greece and Yugoslavia)
Describe how the process of overfatness occurs. What leads to increase in chance for adult obesity? Also how does weight gain change over the years?
Overfatness -long term process
Overfatness represents a Heterogeneous disorder in which Energy INTAKE EXCEEDS energy Expenditure
Disruption in energy balance often begins in Childhood, which INCREASES the chance for adult obesity considerably
between ages 20 and 40, Americans gain about 2 pounds a year for a 40-pound gain in body weight
-Women tend to gain the MOST weight
Explain the reasons for classifying overweight and obesity
Reasons for Classifying overweight and obesity:
-Provides meaningful comparisons of body weight status within and between populations
-Identifies Individuals and groups at increased risk of morbidity and mortality
-Identifies priorities for intervention at the individual and community levels
-Establishes a firm basis for evaluating diverse intervention strategies
it will help ID individuals at risk for comorbidities, and intervene and help decrease morbidity, mortality long term
What genes are involved in obesity?
Genes are involved in causing obesity:
also different organs produce substances or hormones that lead to obesity:
GI tract
Adipose tissue create Leptin
Stomach produces Grehlin
pancreas produces insulin
these organs and dopamine and serotonin all input into nervous system and affect your desire for food.
