Chapter 8: The Physiology Of Obesity Flashcards
Having BMI greater than 25 starts to rise at age _ and dec,ones around age _
35
75
_ % of the worlds population live in countries where obesity kills mo re people than being under weight
65%
_ refers to a body weight that exceeds a predetermined average for height
Overweight
Excessive accumulation of body weight
_ % above ideal body weight
Obesity
20%
Obesity body fat %
Men
Women
Men - over 25%
Women - over 32%
BMI calculation
BMI = weight (kg) / height *squared (m)
Lbs to kg
Lb/ 2.2
Inches to meters
Inches x .0254
BMI
Less 18
Underweight
BMI
18-24.9
Normal weight
BMI
25 - 29.9
Overweight
BMI
30 - 39.9
Obese
BMI
40 or higher
Morbidly obese
BMI _ fatness in athletes because of their
Overestimate
Muscular build
BMI might _ fatness in older persons due to _
Underestimate
Loss of muscle
Weighing a person fully submerged in water - difference been persons mass in air and in water
Hydrostatic weighing
Body comp measurement that measures the resistance to electric current flow as it passes through the body
BIA
Bio electrical impedance
BIA
Impedance is greatest in _
Fat tissue
Fat free mass contains _ % water
70-75%
Body volume assessment using air
Air displacement plethysmography
Body comp assessment that involves use of light absorption and reflection to estimate percent fat and percent fat free mass
Body fat absorbs light
Lean body mass reflects lights
NIR
Near infrared interactance
Existing fat cells increase increase in size. Fill with fat
Fat cell hypertrophy
Total fat cell number increases
Fat cell hyperplasia
The number of fat cells _ in spite of weight gain or loss
Remains constant
Obesity that occurs early in life can cause an increase in number of fat cells - which is called (2)
Hypercelluar or hyperplastic obesity
Enlargement of existing fat cells, but normal fat cell number
*occurs later in life
Hypertrophic obesity
Hypertrophic obesity associated with _ fat distribution (2)
Truncal ( apple shape)
After age 20 a _ to _ increase in body weight correlated with _ % greater risk of death from coronary artery disease
4% to 10%
50%
Android obese store fat
In the abdominal region
Gynoid obese store fat in the
Hips, butt and thighs
Abdominal fat increases risk of disease because
Fat in abdomen is more easily releases into th bloodstream increasing disease related blood fat levels
WHR - indicative of android obesity
Men
Women
Men .95 or above
Women .86 or above
Women with waist measurement higher than _ develop heart disease twice as frequently as slim women
30 inches
Waist circumferences display elevated cardiovascular risk profiles
Men
Women
Men 40”
Women 35”
3 factors of maintaining body weight
Metabolic utilization of nutrients
Dietary habits
Physical activity
Cognitive drive to consume too many calories, physical defect in appetite regulation or inappropriate response to stress
Active overeating
Consumption of normal amount of food becomes excessive due to sedentary lifestyle
Passive overeating
Thermic effect of:
Fat
Protein
Carbs
Fat 0 - 2%
Protein 25-30%
Carb 6-8%
_ overeating contributes to the obesity epidemic more so than _ overeating
Passive
Active
3 components of human daily energy expenditure
Basal metabolic rate
Thermic effect of food
Thermic effect of physical activity
This accounts for 60-75% of daily energy expenditure
Energy required for vital, resting bodily functions
Basal metabolic rate
reduced energy expenditure increases person’s tendency to _
due to _
overeat
fat content in food providing excessive amounts of calories
This accounts for 10% of daily energy expenditure
thermic effect of food
This accounts for 15-30% of daily energy expenditure
thermic effect of physical activity
NEAT
nonexercise activity thermogenesis
energy expenditure can vary by as much as _ between individuals
2,000 calories / day
*LONGTERM CONTROL OF ENERGY INTAKE. functions as satiety signals to decrease food intake when energy levels are met - SECRETED IN RESPONSE TO ELEVATED BLOOD GLUCOSE LEVELS
stimluates _ neuron
insulin
POMC - appetite inhibiting neuron
appetite-inhibiting neuron
POMC proopiomelanocortin
appetitie-stimulating neuron
Neuropeptide Y NPY
_ is a hormone that acts on the hypothalamus in the brain via a negative feedback loop to regulate energy intake
*appetite regulator
leptin
_ deposits into the adipocyte cause a release of leptin which triggers the hypothalamus to to reduce appetite and the drive to eat
triglycerides
leptin transport across the blood brain barrier is impaired in _ individuals
obese
*leptin resistant
weight loss _ leptin levels and weight gain _ circulating levels
reduces leptin
increases circulating levels
weight loss may activate neuroendocrine mechanisms: 4
stimulate hunger
decrease energy expenditure
decrease thyroid levels
slow metabolism
_ is a hormone secreted in the small intestine that slows gastric emptying and and send satiey signals to the hypothalamus
*PROVIDES SHORT TERM INFO ABOUT HUNGER
cholecystokinin (CCK)
stimulates hunger, hunger hormone, prepares the body to deal with incoming food
- short term info about hunger and satiety
- stimulated frowth hormone release from pituitary gland
ghrelin
_ hormone released from the colon and rectum
acts on hypothalamus to suppress appetite 2-6 hours after a meal
acts on pancreas to increase digestive juices
stimulates gallbladder to release bile
peptide YY
_ levels are lower in obese individuals than lean individuals
*reduces ghrelin
peptide yy
genetics influence appetite and metabolism _%
25%
2 ways genes contribute to obesity:
rare mutations (ex lacking the gene that produces leptin)
poygenic obesity - genetic variants that interact with “at-risk” environment
RMR is _ in white women than in black women
attributed to _
higher
lower organ mass in black women (organ mass is metabolically active)
