energy intake and expenditure

Question 1

how to break down the word ‘deaminase’ to work out its function?

Answer 1

ase = enzyme
de = removal
amine = amine group 

so deaminase = enzyme that helps with the removal of amine group

Question 2

can you get energy from micronutrients?

Answer 2

no, they don’t give energy only help with the process

Question 3

what is the law of energy and how is it predominantly used in the body?

Answer 3

energy cannot be created or destroyed, just moved from one form to another

most chemical energy in the body goes to heat (80-85%) so not very efficient

Question 4

what is the gross efficiency equation?

Answer 4

(work accomplished / energy expended) x100

Question 5

what is the net efficiency equation?

Answer 5

(work accomplished / energy expended - resting energy expenditure) x 100

Question 6

what is the equation of work efficiency?

Answer 6

(work accomplished / energy expenditure - energy expenditure in unloaded) x 100

takes into account 0W

Question 7

what is the equation for delta efficiency?

Answer 7

(change in work accomplished / change in energy expenditure) x 100

Question 8

what are the 2 harder ways to measure energetic efficiency?

Answer 8

work and delta efficiency

Question 9

what is the energy content per gram of lipids, carbohydrates and protein and alcohol?

what is the digestibility of each nutrient and the resulting usable energy?

Answer 9

lipid - 9.45 kcal - 95% - 9 kcal

carbohydrate - 4.3 kcal - 97% - 4 kcal

protein - 5.65 kcal - 92% - 4 kcal
varies depending on nitrogen content

alcohol - 7 kcal - 100% - 7 kcal

Question 10

what are the proportions that energy expenditure occurs in?

Answer 10

basal metabolism - 60-75%
admr, bmr and rmr

thermogenesis - 10%
tef and dit

physical activity - 15-30%
tee and eea

Question 11

in what conditions will body weight remain stable?

Answer 11

when Total Daily Energy Intake (TDEI) = Total Daily Energy Expenditure (TDEE)

Question 12

what happens when TDEI is less than TDEE?

more energy expenditure than intake

Answer 12

body uses stored energy to make up the difference (when this imbalance occurs over a prolonged period)

Question 13

what are the main organs which use energy during rest and what proportion of total energy do they use?

Answer 13

liver - 20%
brain - 19%
skeletal muscle - 18% (significantly increases during exercise)
kidneys - 10%
heart - 7%

Question 14

what does ADMR stand for?

components of energy expenditure

Answer 14

average daily metabolic rate

Question 15

what does bmr and rmr stand for?

components of energy expenditure

Answer 15

basal metabolic rate
resting metabolic rate
resting rate will be higher as not in such strict resting conditions as in a lab

Question 16

what is tef and dit?

components of energy expenditure

Answer 16

thermic effect of food (digestion and absorption)
diet induced thermogenesis
tef=dit (the same)

Question 17

what does tee stand for?

components of energy expenditure

Answer 17

thermic effect of exercise

as heat produced during exercise

Question 18

what does eea stand for?

components of energy expenditure

Answer 18

energy expenditure for physical activity

Question 19

describe the usage of the direct calorimetry chamber to measure metabolic rate?

pros and cons?

Answer 19

small insulated chamber with ventilation

measures energy expenditure in the form of heat - O2 inspired and CO2 expired

cons: expensive, not ptable, need trained people
pros: can be made into a suit (not much better)

Question 20

describe the usage of the respiratory chamber to measure metabolic rate?

pros and cons?

Answer 20

measurement of oxygen in and carbon dioxide out (hours-days)

pros: food intake can be measured and urine and faeces can be collected (measure energy and nitrogen balance)
cons: expensive and need highly trained people

Question 21

how can you use measurement of inspired and expired gas to measure resting metabolic rate?

what is this measurment called?

what else can it measure?

what are the pros and cons?

Answer 21

indirect calorimetry - measure the relative contribution of CO2 and O2 in each breath

can also use to understand amount of fat and CHO being burned

pros: immediate analysis and continuous measurement and measure more people than direct calorimetry chamber and non-invasive
cons: doesn’t distinguish between carbs and fat

Question 22

describe the usage of doubly labelled water to measure metabolic rate?

pros and cons?

Answer 22

2H2 18O
can measure and track the water in body

pros: free living
cons: expensive

Question 23

difference between energy cost in very light compared to strenuous activities?

Answer 23

very light: 3-5 kcal/min

strenuous: more than 13 kcal/min

Question 24

which factors determine amount of energy burned during running?

Answer 24

distance and body mass

1kcal per kg BM per km

Question 25

what are the effects of prolonged existance at the lower limits of energy?

Answer 25

1000-1500 kcal per day
anaemia
amenorrhea
decreased body mass
low bone mineral density

Question 26

what are some of the ways to measure energy intake?

issues with this type of measurement?

Answer 26

self report:
(but people will under report by roughly 20%)

24h recall

3/7 day food diary

food frequency questionnaire

diet history (cross between 24h recall and food frequency questionnaire)

Question 27

what most accurate way to measure energy intake and why?

Answer 27

conduct a 3 day weighted food diary
2 weekdays and 1 weekend day

allows calories and macro/micro nutrient intake to be measured

as 7 days produces less high quality data

Question 28

which eternal factors may increase or decrease resting metabolic rate?

Answer 28

increase - caffeine, carbohydrate intake, exercise, protein, food

decrease - starvation, hot temperature

Question 29

what equipment is needed to measure indirect calorimetry with a cortex?

Answer 29

hair net
mask
turbine
turbine casing