study 13,14,&15 Flashcards
Energy in (food) =
Energy out (how body uses calories)
Energy equilibrium-
no change in fat stores (weight).
Energy in > Energy out =
increased fat stores (weight gain) (adipose tissue)
Energy in < Energy out =
decreases fat (decreases weight)
Total energy expenditure (calories use) =
metabolism (cals to stay alive) +
physical activity (muscle movement)+
calories needed to metabolize & store nutrients
Basal (minimum) metabolism (measuring o2 in and co2 out) -
minimal calories (in morning before arise)
Organ that uses the most energy -
Liver
Male
1.0 kcal/kg-hr.
female
0.9 kcal/kg.hr
BMR (basal metabolism rate)
your weight (m/f) /2.2kg x 1.0 kcal (M) x 24hrs. =
Influence on Metabolism
- muscle mass/lean body mass
- surface area
- thyroid hormone regulates metabolism
Increases metabolism
growth, fever, stress, exercise, smoking
Decreases metabolism
aging (2% every 10 years), dieting
factors decrease
lower lean body mass, lower height, older age, depressed levels of thyroid hormone, starvation, female
Non-exercise activity thermogenesis
NEAT
thermic effect of food (energy cost of eating food)
energy for digestion absorption transport, storage of nutrients - 10% of calories
physical activity (out of energy expenditure)
varies the most among individuals
% Body fat
Male - 10-20%, Female 20-30% fat
Skinfold measurements (fatfold)-
measures subcantaneous fat (under skin)
calipers (measurement device)
should correlate with total body fat
Underwater weighing-
determines body density, less dense = more fat
Air displacement-
density measurement
Bioelectrical empedance analyis
measures the intensity of electrical current. fat impededs the flow of electricity/lean tissues conducts electricity
Healthy Weight (% body fat)
- waist circumference
- suggests location of body fat
- visceral fat (more dangerous)
- subcantaneous fat
- waist to hip ratio
- body mass index (weightkg/height m2)
BMI (body mass index)
problems- body builders, muscular people have increased BMI
-ideal BMI varies with different ethnic groups
Waist circumference
Female - 35” Male - 40”
Healthy BMI-
18.5-25,
overweight- 25-30
Obese - over 30
Problems with BMI-
doesn’t indicate location of bodyfat- include waist circumference
obesity
excessive body fat
Health risks of obesity
- heart disease
- cancer
- stroke
- diabetes
- arthritis (hips&knees)
- gallstones
- respiratory illness
Causes of obesity
E in > E out, environmental factors (food intake, exercise, culture, habits)
Genetics (proof role in obesity)
2 parents obese - 80%risk in children
0 “ “- 10% risk
Adopters- weights of biological higher versus adopted parents
Identical twins- have same body composition
Genetic influence - genes = protein “obesity genes”
increased food intake - decreased expenditure
- some proteins in digestive tract
- some proteins in fat tissue
- metabolism?
- activity?
Leptin (protein in fat tissue)
adipose cells(fat cells) make leptin - signals brain to adjust food intake
Ghrelin (stomach hormones)
-signals “hunger” to brain, induces hunger intake, stimulates food to brain
Uncoupling Proteins
affects energy expenditures (increased heat loss)
