E2 body composition Flashcards
what are the two types of storage fat
visceral and subcutaneous
what are the recommendations for fat percentage
– 8–19% for men, recommended low end of 12–15% for
young adults
– 21–32% for women, recommended low end of 21–25%
for young adults
– Athletes or very active individuals might have lower
values
what is visceral fat
fat stored around the organs
what is subcutaneous fat
fat is stored between the skin and
muscle layers.
what are the current obesity estimates
– 34% of adults
– 17% of children/adolescents (ages 2–18)
– 10% of all medical costs in United States
– $200 billion per year direct medical costs
what are the chronic conditions of overweight/obesity
- Cardiovascular disease (CVD)
- Certain types of cancer (Colon)
- Hypertension (or high blood pressure)
- Kidney disease
- Arthritis, joint problems, and osteoarthritis
- Diabetes (Type 2)
- Alzheimer’s disease
- Menstrual abnormalities/pregnancy issues
- Sleep apnea
- Gallbladder disease
what are the health effects of being underweight?
- Loss of muscle mass and strength resulting from malnutrition
- Osteoporosis
- Menstrual abnormalities that can lead to infertility
- Underweight related to eating disorders (anorexia nervosa and bulimia) can
lead to:
– Heart problems
– Digestive disorders
– Kidney damage
– Anemia
– Lethargy
– Muscle weakness
– Dry skin
– Poor immune function
what are the methods for assessing body composition?
- Field methods- less accurate
– Height/weight tables
– Body mass index (BMI)
– Skinfold test
– Waist measurement & waist-to-hip ratio - Laboratory measures -more accurate
– Dual energy X-ray absorptiometry (DXA)
– Hydrostatic weighing
– Air displacement
– Bioelectrical impedance analysis (B IA)
how is BMI calculated
weight(kg)/height (m)2
what are the test sights for the skin fold test for men and women?
men
-abdomen
-chest
-thighs
women
-supralium -super iliac (side abdomen)
-tricep
-thigh
what are the advantages and disadvantages of each measure of body composition?
BMI:
-does not estimate body fat
-no cost or special equipment required, fast and easy
-limited estimation on body composition
SKINFOLD:
-estimates body fat
-accurate and low cost
-trained technician required
WHR:
-does not estimate body fat
no cost, fast and easy
-limited estimate of body composition
DXA:
-estimates body fat accurately
-certified technician required , high cost, limited availability, time consuming
hydrostatic weighing:
-estimates body fat
-accurate with reasonable costs
-trained technician required
-subjects limited to those not afraid of water
what is the relationship between sugar and obesity?
eating excess
amounts of added sugar
can have harmful effects
on metabolism, leading
to insulin resistance,
belly fat gain, high
triglycerides and LDL
cholesterol.
what are the causes of obesity?
Energy imbalance over a long period of time
* Energy in > Energy out
(Food intake) (Exercise/physical activity)
* Excess calories + lack of physical activity
what functions in your body need to spend energy?
Necessary physiological functions
(eating, digesting, sleeping, breathing)
Heart (cardiac muscle) uses energy
even at rest
Function of brain, lungs, circulation,
etc.
Kidney function (filtration of waste from
blood)
Generating heat to keep warm
Movement and exercise
what is the cycle of inactivity?
-childhood inactivity
-childhood obesity
–inactive adults
-obesity, chronic diseases and increased risk of death
-increased healthcare cost
repeat
how does your brain register food?
regulating our energy balance
(regulates appetite)
* Brain doesn’t “register” liquid sugar
calories in the same way as it does
solid calories
* If you consume a certain number of
calories from a sugary drink, your
brain doesn’t automatically make you
eat fewer calories of something else
instead
what is the relationship between sleep and obesity?
negative effects on various
hormones that are related to
weight gain, and can
contribute to increased
hunger and cravings.
* As it turns out, short sleep
duration is one of the
strongest individual risk
factors for obesity. It is linked
to an 89% increased risk in
children, and a 55%
increased risk in adults
explain the rat overeating study
rats were split in to 3
groups
* 1st group got healthy food, 2nd
group got one type of junk
food, but the 3rd group got
multiple types of junk food at
the same time.
* There is evidence that this is
true in humans as well.
* When we have more types of
foods available, we eat more
* Sometimes more than
our bodies need.
* Food challenges
how is fat stored?
stored in the body in the form of triglycerides (TG).
– TG are made up of 3 free fatty acid molecules held together by a
molecule of glycerol
-stored in fat cells - adipocytes
-can also be stored as droplets within skeletal muscles- intramuscular triglycerides
-some travel freely in the blood
how has calorie consumption increased over the past few decades
calorie consumption has
increased dramatically over the
past few decades
* According to studies, this
increased calorie intake is more
than sufficient to explain the
increases in obesity
define lipogenesis and glycogenesis
– Lipogenesis (genesis = generation)
Process that leads to the deposition
of lipids and the growth of fat tissue
define lipolysis
– Lipolysis: (lysis = breakdown)
Process of fat breakdown and
removal.
your energy needs increase or your blood glucose level falls,
the production of hormones that mobilize your energy stores begins to
rise.
* Fat mobilization and Fat metabolism
– Hormone Stimulated (epinephrine)
– Released by the sympathetic nervous system during exercise
– Physical Activity enhances fat mobilization responsiveness
– Obesity: blunts responsiveness, more epinephrine needed
– These hormones stimulate lipolysis
▪ Involves the breakdown of triglycerides stored in your fat tissue.
how is body fat controlled
fat stores in your body are
metabolically active and
dynamic tissues.
* Two opposing forces determine
the amount of fat you carry
around from day to day.
– Lipogenesis (genesis = generation)
Process that leads to the deposition
of lipids and the growth of fat tissue
– Lipolysis: (lysis = breakdown)
Process of fat breakdown and
removal.
what cells does insulin act on the body to store glucose fat and protein
liver, adipose tissue, skeletal muscle,
describe the insulin process
- Blood glucose is high after a meal
- High glucose levels send signal to the pancreas
- Pancreas releases insulin
- Insulin acts on multiple cells in the body to store the glucose, fats,
proteins in liver, adipose tissue, skeletal muscle, etc. - As a result, blood glucose back to normal levels (~100mg/dl)
what is essential fat and where is it located
in nerves and cell membranes, necessary for body function
how much essential fat is needed for both men and women?
women- 12%
men- 3%
how do you calculate BMI
body weight divided by height squared
what BMI is healthy and obese
under 25 is healthy over 30 is obese
when is lipolysis stimulated
when energy levels increase or glucose levels fall
what hormone stimulates fat mobilization and fat metabolism
epinephrine
how is epinephrine released
-sympathetic nervous system during exercise
-activity enhances fat mobilization and responsiveness, unlike obesity which stunts it
define lypogenesis
the process that promotes lipid deposition, storage and growth of fat tissue
what triggers insulin production
eating food- increase in blood glucose
fasting- decrease in insulin production
how is glucose absorbed by insulin
triggers glucose uptake by liver, muscle and fat cells
how are fatty acids taken by insulin
stimulates uptake of fatty acids by fat cells, lipids are converted to triglycerides then stored for future
what processes do insulin promote and inhibit and why
promotes lipogenesis as increase in energy level requires storage.
inhibits lipolysis- why diabetics
describe the insulin cycle
1- blood glucose level increase
2-pancreas releases insulin
3- triggers liver to convert glucose to glycogen, or cells to absorb/uptake glucose
4-normal levels return
what are the normal glucose levels
100mg/dl
how is body fat burnt
1- lipolysis, which realeases the fat from the cell
2-oxidation: then blood flows the fat to another cell to be burnt (used) and generate ATP at mitochondria
why is certain fat “stubborn”
has a higher density of alpha receptors which are more insulin receptive and receive less blood flow- which means epinephrine won’t bind to it.
subcutaneous is more stubborn
how much of a cal surplus do you have to be in to gain one pound a year
1lb=3111kcal
how much percentage energy expenditure is BMR, TEF, and activity
BMR- 60-75%
TEF-10%
Activity- 15-30%
how do you calculate BMR for men and women
men- (10xw) + (6.25xh) - (5xa) -161
women - +5
how many calories are burned through processing each macronutrient
protein- 20-35%
fat- 0-5%
carbs- 10-30%
fibrous veg- 20%
define gluconeogenisis
the process that creates glucose from non carb sources like fat and protein- in liver and kidneys
define glycosis
breakdown of glucose into pyruvate or lactate
