Body Composition and Nutrition Flashcards
Describe essential fat
- fat in the heart, lungs, liver, spleen, kidneys, intestines, muscles, & lipid-rich tissues of the CNS & bone marrow, includes sex-specific fat in females
- normal physiologic functioning requires this fat
Describe storage fat
- fat packed primarily in adipose tissue
- includes visceral fat that protect the various internal organs & subcutaneous fat
Define lean body mass (LBM)
- contains the small percentage of non-sex specific essential fat equivalent to about 4-7% of body mass
define fat free body mass (FFM)
- body mass devoid of all extractable fat
Criteria to identify an underweight adult female
- body mass lower than minimal body mass calculated from BMI
- body mass <20th percentile by stature (height)
- body fat <17% assessed by a criterion method
Describe minimal leanness standards
- lower limit beyond which body mass cannot decrease further without lowering fat free mass to a degree that impairs health or alters normal physiologic functions
- Male: 3%
- Women: 12%
Physically active women, particularly participants in the “low weight” or “body appearance” sports, increase their likelihood for one of three medical maladies
- delayed onset of menstruation
- oligomenorrhea
- amenorrhea
Define oligomenorrhea
- irregular menstrual periods
Define amenorrhea
- abnormal absence of menstruation
Describe what largely contributes to menstrual dysfunction
- changes in the pituitary gland’s normal pulsatile secretion of luteinizing hormone, regulated by gonadotropin releasing hormone from the hypothalamus
What are the two general approaches to determine the fat and fat free components of the human body
- direct measurement by chemical analysis or dissection
- indirect estimation by hydrostatic weighing, anthropometric measurements, and other simple procedures including body stature & mass
What is the gold standard for indirect body mass measurement
- hydrostatic weighing/archimedes’ principle
Siri equation for percentage body fat
percentage body fat = 495 ÷ body density - 450
Mass of body fat equation
Fat mass (kg) = body mass (kg) X (percentage fat/100)
Free fat mass equation
- free fat mass (kg) = body mass (kg) - fat mass (kg)
Describe BOD POD
- looks at air displacement
- you look at how much air is in the pod and once a person is in the pod you take the difference in the amount of air in the pod
- temperature and level of hydration matters for the accuracy
Describe skinfold measurements
- measure pinch below your head = grab above pinch below
- have to release the handle and take a reading
- always measure on the right side starting from the top to bottom & do it twice but if measurements are more than 2-3 cm different take a 3rd measurement & take the average
What are the two practical ways to use skinfold
- sum the individual skinfold values to indicate relative fatness among individuals; it also reflects absolute or percentage changes in fat fatness before and after a physical conditioning or dietary regimen
- apply mathematical equations to predict body density or percentage body fat from the individual skinfold values
Describe girth measurements
- easy to take
- focus on the abdomen, waist, and hips
- waist is the smallest part of your torso from the front and back
- abdomen is around the umbilical level or around the iliac crest
- hip is at the widest part of your buttocks from the side
Describe bioelectrical impedance analysis
- uses principal of electrical conductivity
- water is a better conductor than fat
- if the speed is faster, then we assume more water meaning more muscle and if slower than we assume more fat
Describe dual energy Xray absorptiometry (DEXA)
- quantifies fat and muscle around bony areas of the body including regions without bone present
- the computer generated report quantifies bone mineral content, total fat mass, and free fat mass
- 2 xray energies penetrate into bone and soft tissue areas to a depth of about 30 cm
Describe body mass index (BMI)
- BMI = mody mass (kg) ÷ stature/height (m^2)
- BMI doesn’t consider the body’s fat & non-fat components so a high BMI can lead to an incorrect interpretation of excess body fat in lean individuals with excessive muscle mass
As BMI becomes larger what risk can it increase
- cardiovascular complications
- diabetes
- some cancers
- renal disease
What other indirect procedures to estimate body composition are there but are even more expensive than DEXA
- near infrared interactance (NIR)
- ultrasound
- computed tomography (CT)
- magnetic resonance imaging (MRI)
What are the average fat percentage values for males and females
Males: average between 12-15%
Females: average between 25-28%
How do you determine goal body weight
- Fat Mass = Body Mass (kg) x Decimal % body fat
- Fat Free body mass = Body Mass (kg) - Fat mass (kg)
- Goal Body Weight = Fat Free body mass (kg) ÷ (1.00 - Decimal % fat desired)
- Desirable Fat loss = Present body weight (kg) - Goal body weight (kg)
What is the BMI for underweight, normal, and overweight
Underweight: <18.5
Normal: 18.5-24.9
Overweight: 25.0-29.9 with < 40 in waist (Men) & < 35 in waist (Women) you have increased disease risk and with > 40 in waist (Men) & > 35 in waist (Women) you have high disease risk
Level of risk for men with < 40 in waist or women with < 35 in waist at different obesity BMI’s
BMI 30.0-34.9 = obesity class I with high disease risk
BMI 35.0-39.9 = obesity class II with very high disease risk
BMI > 40.0 = obesity class III with extremely high disease risk
Level of risk of men with > 40 in or women > 35 in waist at different obesity BMI’s
Obesity class I is very high disease risk
Obesity class II is very high disease risk
Obesity class III is extremely high disease risk
Describe obesity
- according to the World Health Organization (WHO) obesity represents a complex condition with serious social & psychological dimensions that impacts all age & socioeconomic groups and threatens to overwhelm both developed and developing countries
Cause of obesity
- includes a complex interaction of factors, including genetic, environmental, metabolic, physiologic, behavioral, social, and perhaps racial influences
Individual differences in specific factors that predispose humans to excessive weight gain include
- eating patterns & eating environment
- food packaging
- body image
- variations related to resting metabolic rate
- diet induced thermogenesis
- level of fidgeting
- basal body temp.
- susceptibility to specific viral infections
- levels of cellular ATP
- lipoprotein lipase
- levels of metabolically active brown adipose tissue
Adverse changes in diet leading to obesity include
- shifts in dietary structure towards higher energy density with greater fat & added sugars
- greater saturated fat
- reduced complex carbohydrates & dietary fiber
- reduced fruit & vegetable intakes
What is the estimated percentage of all US adolescents that eat fast food one or more times per week
- 75%
Do genetics cause obesity
- genetic makeup does not necessarily cause obesity, but it does lower the threshold for its development
- in an obesity producing environment, the genetically susceptible individual gains weight
What helps against obesity
- regular physical activity effectively impedes weight gain & the adverse changes in body composition
- individuals who maintain weight loss over time chow greater muscle strength & engage in more physical activity than counterparts who regained lost weight
- maintaining a lifestyle that includes a regular, consistent level of endurance exercise attenuates but does not fully forestall the tendency to add extra weight through middle age
What are the 10 major health consequences of obesity
- cardiovascular disease
- type 2 diabetes
- hypertension
- dyslipidemia
- ischemic stroke
- sleep apnea
- degenerative joint disease
- some types of cancer
- gallstones
- fertility problems
3 appropriate approaches to measure a person’s fat content
- percentage of body mass composed of fat
- distribution or patterning of fat at different anatomic regions
- size & number of individual fat cells
Two types of regional fat distribution
- central or android type obesity
- peripheral or gyroid type obesity
What is the general guideline for waist to hip ratio to determine risk of death
- waist to hip ratios that exceed 0.80 for women and 0.95 for men increase risk of death even after adjusting for BMI
What does central fat deposition increase
- hyperinsulinemia
- glucose intolerance
- Type 2 diabetes
- endometrial cancer
- hypertriglyceridemia
- hypercholesterolemia
- negatively altered lipoprotein profile
- hypertension
- atherosclerosis
Increases in adipose tissue mass occurs in two ways
- fat cell hypertrophy (cells getting larger)
- fat cell hyperplasia (cells are dividing)
Does hypertrophy or hyperplasia happen first
- hypertrophy happens before hyperplasia happens
How many fat cells does the average person and obese person have
Average person: about 25 to 30 billion fat cells
Obese person: between 60 to 100 billion
Massively obese person: about 360 billion or more
Ways to unbalance the equation to produce weight loss
- reduce caloric intake below daily energy requirements
- maintain caloric intake and increase energy expenditure through additional physical activity above daily energy requirements
- decrease daily caloric intake and increase daily energy expenditure
Energy balance equation
Weight change = Total energy intake - Total energy expenditure
Effects of drugs as an intervention strategy
- decrease appetite
- increase thermogenesis
- increase resting metabolism
Effects of surgery as an intervention strategy
- decrease food absorption
Effects a behavior therapy as an intervention strategy
- decrease food intake
- increase physical activity
What does a high protein diet have the potential to cause
- strain on liver and kidney function and accompanying dehydration
- electrolyte imbalance
- glycogen depletion
- lean tissue loss
Protein rich foods often contain high levels of saturated fat, increasing risk for heart disease & type 2 diabetes (True/False)
- True
Describe semi starvation diets
- very low caloric diet may benefit severe clinical obesity where body fat exceeds 40-50% of body mass
- requires close supervision, usually in hospital setting
- provides between 400 & 800 kcal daily as high quality protein foods or liquid meal replacements
Strategies to affect weight loss
- hydration level & duration of the energy deficit affect the amount & composition of weight loss
- takes about 4 weeks to establish the desired pattern of fat loss for each pound of weight loss
- restricting water during the first few days of a caloric deficit increases body water lost and decreases fat loss
- shorter periods of caloric restriction produce a larger percentage of water & carb loss per unit weight reduction with minimal decrease in body fat
What losses the most in the first week of weight loss
- water 70%
- fat 25%
- protein 5%
What losses the most in the 2nd to 3rd week of weight loss
- fat 70%
- water 20%
- protein 10%
What losses the most in the 4th week of weight loss
- fat 85%
- protein 15%
Effects of increased physical activity & food intake
- increased physical activity by overweight, sedentary individuals does not necessarily alter physiologic needs & produce compensatory increases in food intake to balance additional
Effects of low caloric stress of physical activity
- the caloric expending effects of increased physical activity add up & a caloric deficit of 3500 kcal equals a 0.45 kg body fat loss, whether the deficit occurs rapidly or systematically over time
Effectiveness of regular exercise
- modifies the composition of the weight lost in the direction of greater fat loss
- effectiveness relates closely to the degrees of excess body fat
- most of the health related metabolic improvements with regular exercise in the obese relate to total exercise volume & quantity of fat loss
- a reasonable goal progressively increases moderate exercise to between 60 & 90 minutes daily or a level that burns 2100 to 2800 kcal weekly
Common misconceptions in weight loss
- increased physical activity and food intake
- low caloric stress of physical activity
- spot reduction
Describe spot reduction
- stems form the belief that an increase in a muscle’s metabolic activity stimulates relatedly greater fat mobilization from the adipose tissue in proximity to the active muscle
- exercise stimulates mobilization of fatty acids via hormones and enzymes that act on fat depots throughout the body not simply from areas closest to the active muscle mass
- the negative energy balance created through regular exercise contributes to reducing total body fat
- this is a misconception
Define kilocalorie
- the quantity of heat necessary to raise the temperature of 1 kg of water 1 degree Celsius
How many kcal does one gram of carbohydrate, protein, and fat
Carbohydrate: 4 kcal per 1 gram
Protein: 4 kcal per 1 gram
Fat: 9 kcal per 1 gram
What things must a food label display
- product’s common or usual name
- name & address of manufacturer, packer, or distributor
- net contents for weight, measure, or count
- all ingredients listed in descending order of predominance by weight
- serving size, number of servings per container, & caloric information
- quantities of specified nutrients & food constituents
- descriptive terms of content
- approved health claims stated in terms of the total diet
Average daily energy intake for males and females
- males always require more calories than females do
Describe pre-competition meal
- provides the athlete with adequate carbohydrate energy, & ensures optimal hydration
- foods high in lipid & protein should not be consumed on competition days
-consider food preference, psychologic set, & food digestibility when individualizing an athlete’s meal plans
What diet gives you the most amount of time before exhaustion & most muscle glycogen and what diet gives you the least
- high carbohydrates and low fat diet gives you the most time before exhaustion and the most muscle glycogen
- high fat and low carbohydrate diet gives the least amount of time before exhaustion & least muscle glycogen
What is the ideal pre-competition meal
- it maximizes muscle & liver glycogen storage & provides glucose for intestinal absorption during exercise
- contains 150 to 300 grams of carbohydrate
- is consumed within 3 to 4 hours before exercising
Describe carbohydrate intake during exercise
- consuming about 60 grams of liquid or solid carbs each hour during exercise benefits long duration intense exercise & repetitive short bouts of near maximal effort
What does exogenous carbohydrate accomplish
- spares muscle glycogen because the ingested glucose powers the exercise
- helps stabilize blood glucose, which prevents headache, lightheadedness, nausea, & other symptoms of CNS disease
Describe carbohydrate intake after exercise
- meant to facilitate glycogen repletion, one should immediately consume carbohydrate rich, high glycemic index foods
- consume 50 to 75 grams of moderate to high glycemic carbohydrates every 2 hours for a total of 500 grams
Describe the ideal rehydration beverage
- tastes good
- absorbs rapidly
- causes little or no gastrointestinal distress
- helps maintain extracellular fluid volume & osmolality
- offers potential to enhance exercise performance
Practical recommendations for fluid intake
- monitor dehydration rate from changes in body weight
- drink fluids at the same rate as their estimated rate of depletion
- drink between 625-1250 ml each hour of a 4-8% carbohydrate beverage
- 400-600 ml of fluid immediately before exercise
- fluid temperature probably does not play a major role in replenishing fluid during exercise
- avoid beverages containing alcohol or caffeine
- educate elderly to drink regularly when not thirsty & to moderately increase their salt intake when they sweat
What does adding a moderate amount of sodium to ingested fluid do
- maintains plasma osomolality
- reduces urine output
- sustains the drive to drink
What is ACSM’s recommendation for sports drinks
- recommends they contain 0.5 to 0.7 grams of sodium per liter of fluid consumed during exercise lasting more than 1 hour
Describe carbohydrate loading
- a particular combination of diet plus exercise produces a significant “packing” of muscle glycogen
- the technique increases muscle glycogen levels more than levels achieved by simply maintaining a high carbohydrate diet
Describe classical loading procedure
- 5 to 7 days before competition
- reduce intensity/taper training to store extra carbohydrates
Describe modified loading procedure
- 4 to 5 days before competition
- intensity of training stays the same
Describe rapid loading procedure
- day before or day of competition
- take in extra carbs that will be lost during the event and won’t be stored
In what order is carbs, protein, & fat the hardest to breakdown therefore takes more energy to breakdown
- Protein is the hardest
- Carbohydrates
- Fat is the easiest to breakdown
Describe the effects of fiber
- fiber helps with feeling satiated
- fiber will delay the absorption of carbohydrates & prevents the spike in insulin which blocks leptin making you feel hungry
