energy out is greater than energy in which tends to lead to loss of weight
what is positive energy balance?
energy in is greater than energy out which tends to lead to weight gain
how many calories equal a pound of fat?
3500 calories
define basal metabolism (BMR)
the minimum amount of energy needed to maintain life
what are the components of energy expenditure and what are their percentage?
Basal Metabolism at 50-65%
Physical activity at 30-50%
Thermic effect of food (TEF) at 10%
what is TEF?
thermic effect of food, which is energy expended to digest, absorb and transport nutrients
what percent of energy expenditure does TEF take?
Thermic effect of food (TEF) is about 10%
what factors can increase of lower BMR?
age
height
growth
body composition
stress
hormones
smoking
caffeine
sleep
why is the location of body fat important?
its important because central obesity or upper-level fat has been associated with heart disease, diabetes, insulin resistance, hypertension and some types of cancer
what types of risk are associated with the apply shape body?
heart disease, stroke, diabetes, hypertension and some cancers
what are the risks associated with a pear shape body?
disease has not been associated with the pear shape body
what is the relationship between waist circumference and diseases?
as waist circumference increase so does the risk of diabetes and cardiovascular disease
define hunger
biological need, hunger is the painful sensation caused by a lack of food that initiates food-seeking behavior-
how is hunger turned off/on in the body?
hunger is turned off/on by nerve signals and chemical messengers from the hypothalamus
define satiation
the feeling of satisfaction and fullness that occurs during a meal and halts eating. Satiation determines how much food is consumed during a meal
what turns satiation on or off?
the hypothalamus turns off/or satiation when it receives signals from the stretch of the stomach and activation of CCK hormone
define satiety
the feeling of fullness and satisfaction that occurs after a meal and inhibits eating until the next meal. Satiety determines how much time passes between meals
what is the difference between satiation and satiety?
Satiation stops eating while satiety reminds us not to start eating again
define appetite
the integrated response to the sight, smell, thought or taste of food that initiates or delays eating
what are internal cues for food intake?
nerves signals from stomach
hormones
digestive
leptin
ghrelin, pyy
Brain chemicals
serotonin
neuropeptide y
what are some external cues of food intake?
sight or smell of food
social eating
emotions
define ghrelin
ghrelin is produced by stomach, it goes to the hypothalamus and turns hunger on
define leptin
leptin is is a hormone produced by fat cells, the more fat cells the more leptin in the body. Leptin turns on satiety-the filling of fullness after a meal
define PPY
PPY is peptide YY. It is produced in small intestine in the post absorptive state. It causes ghrelin to decline, turns on satiety
define what neuropeptide Y is
a chemical produced in the brain that stimulates appetite, diminishes energy expenditure and increases fat storage
define BMI
BMI stands for body mass index which is an index of a person's weight in relation to height
what is the purpose of BMI?
to determine a healthy weight range
how is BMI calculated using lbs and inches of height?
pounds divided by inches2 in height x 703
how is BMI calculated using kg and m?
kg (lbs/2.2) divided by meters2 (39.37inch is 1 meter) = BMI
what is the controversy of using BMI?
it does not take in account total body composition. it does not distinguish between an obese person and a muscular person
what are the four different categories of BMI?
underweight is less than 18.5
healthy weight is 18.5-24.9
overweight is 25-29.9
obese is greater than 30
what are the six methods of measuring % body fat?
1-skinfold measure
2-hydrodensitometry
3-bioelectrical impedance
4-air displacement plethysmography
5-dual energy x-ray absorptiometry (DEXA)
which method of determining % body fat is most accurate
skinfold method
define hyperplasia
hyperplasia is an increase number of fat cells in the body
what causes hyperplasia?
whenever energy balance is positive
what is hypertrophy?
an increase of fat cell size
what causes hypertrophy?
when energy intake exceeds energy expenditure
what happens to fat cells when they loose weight?
they become smaller
What is LPL?
LPL is lipoprotein lipase promotes fat storage,its an enzyme that removes triglycerides from the blood for storage in adipose and muscle tissue
what promotes increase of LPL?
estrogen, pregnancy, starving, dieting, weight loss increases LPL activity
what is HSL?
Hormone sensitive lipase, pulls fat out of storage and it breaks down fat for energy use
what affects levels of HSL?
exercise increase HSL activity, dieting and fasting lower HSL activity
what are the downsides of dieting?
it leads to doubling of LPL levels
cuts in half HSL
lowers BMR 8-22%
loss of muscle mass
lowers leptin and increases ghrelin-makes u hungry
what are the characteristics of a healthy weight loss plan?
Energy In
decrease energy in 300-500 cals/day
no magic diet
eating healthy foods
watch portions
don't be restrictive
Energy Out
burn 200-400 calories per day
add exercise
address any underlying emotional issues
true of false?
waist circumference maybe a better predictor of health risk than BMI
