Flashcards
FHN- Energy
Flashcards do conjunto (85)
- 1Name 3 contributors to energy inputFood, Drink, Air, Gut, Skin, Lungs
- 2Name 4 contributors to energy outputFaecal loss, urine, other body fluids, air, gut, bladder, skin, lungs.
- 3what is nutritional balanceintake = loss
- 4intake > losses = ?Positive balance
- 5Intake < losses = ?Negative balance
- 6Name 4 non-degradable nutrientsEnergy, iron, nitrogen, calcium, sodium, trace elements.
- 7Name 4 degradable nutrientsProtein, fat, carbohydrates, fibre, vitamins.
- 8The time it takes to measure balance is dependent on ______The nutrient
- 9Name 5 forms of energyHeat, light, electrical, magnetic, kinetic , potential, chemical
- 10heat + kinetic + potential = ?Chemical
- 11When is chemical energy released?When bonds between atoms in nutrient molecules are released.
- 12What are the units of energy?Joules ( J )
Calories ( cal ) - 131 calorie = ? J4.184
- 14Approximately how many calories does an average adult use per 24 hours?1800 - 3000 kcal
- 15What are the atwater values for the macronutrients?Carbohydrate - 4 kcal/g
Fat - 9 kcal/g
Protein - 4 kcal/g
Alcohol - 7 kcal/g - 16How does a bomb calorimeter work?Food is blended and dehydrated so it can be burnt.
Models are used for food and environmental samples.
Samples are homogenized and dried. - 17What is digestible energy (including equation) ?All energy which isn't excreted including body stores. ~ 96% of energy is absorbed.
DE = GE - Faecal energy. - 18What is Metabolizable energy (including equation) ?Energy which is used, not stored. ~84% GE
ME = DE (fat) + DE (CHO)
+ [0.75 x DE (protein)]
not all protein is digested - 25% lost in urine. - 19What is Net Metabolizable Energy?NME = ME - ΔHE
- 20What is Respiratory Quotient and its equation?Oxidation of macronutrients.
Ratio of CO2 produced to oxygen used.
RQ = CO2/O2 - 21What are the Respiratory Quotients for the macronutrients?Carb - 1.00
Fat - 0.70
Protein - 0.82
Alcohol - 0.67 - 22If a person eats a high fat / low CHO intake will the RQ be high or low?Low
- 23Total Energy Expenditure = ?TEE = Basal metabolic Rate + Dietary induced thermogenesis + energy of physical activity + others.
- 24What is basal metabolic rate?the energy costs of the essential metabolic processes required to maintain life.
- 25What conditions does a person have to be in to measure BMR?lying down, resting (awake), at least 10 hours after last intake, normal body temp, in thermal comfort,
without physical/ psychological stress. - 26What proportion of TEE is BMR?usually 60-70%
can be 50-80% - 27what are the other names for BMR? Why might these be used instead of BMR?Resting metabolic rate (RMR)
Resting energy expenditure (REE)
Same component but may not be measured under such strict conditions as they are often very difficult to maintain. - 28What biological components contribute?Heart and respiratory muscle contractions
Kidney function
Electrical conductivity of nerves
Protein synthesis
Metabolic processes. - 29Fill in the table
- 30Put in order of which contribute more - less of % BMR skeletal muscle, adipose tissue, vital organs1. Vital organs
2. Skeletal muscle
3. Adipose tissue - 31What influences BMR?body comp, sex, age, disease/ injury, thyroid function.
- 32What is Dietary induced thermogenesis?The increase in energy expenditure observed after nutrient intake
- 33What proportion of TEE is DIT?usually 5- 15%
- 34What are other names for DIT?post-prandial thermogenesis
specific dynamic action
thermic effect of food/ a meal - 35What contributes to DIT?Digestion, Absorption, Transport of nutrients, Post-absorptive metabolism, Storage of excess dietary energy.
- 36What influences DIT?Food eaten
Time since consumption - 37If quantity of intake increases will DIT increase or decrease?Increase
- 38If the ratio of CHO : fat increases will DIT increase or decrease?Increase
- 39What is the maximum response time to measure DIT?~ 1 hour after nutrient intake
- 40What is the definition for physical activity?the increase in energy expenditure observed with physical activity.
- 41What proportion of TEE is PA?Usually 20- 40%
Most variable component and depends on the individual - 42What are other names for PA?thermic effect of exercise
thermic effect of activity
activity induced thermogenesis - 43What contributes to PA?Physical movement of the body,
heat loss - 44What influences PA?Activity,
Subject - 45What influences actiivity?Type, intensity, duration, frequency
- 46What influences the subject?Body mass, 'fitness', efficiency
- 47What is the equation for Physical Activity Ratio?energy spent doing activity in x mins/
energy spent in BMR in x mins - 48Give 3 examples of PAR values1.0 - 1.4 - lying, standing
1.5 - 1.8 - driving, washing up
1.9 - 2.4 - cooking, mixed housework
2.5 - 3.3 - showering, walking 3-4 km/hr
3.4-4.4 - gardening, walking 4- 6 km/hr
4.5 - 5.9 - dancing, gentle cycling
6.0 - 7.9 - walking uphill, running
>8.0 - squash, rock climbing - 49What are other components of Energy expenditure?non- exercise activity
adaptive
psychological
cold induced
drug induced - 50What is non- exercise activity thermogenesis? include an exampleNEAT = TEE - ( BMR + DIT + exercise)
eg . fidgeting - 51What are other names for adaptive thermogenesis?non- shivering thermogenesis
facultative thermogenesis
regulatory thermogenesis - 52What is adaptive thermogenesis?Activation or suppression of 'futile cycles'
- 53Explain the effect of psychological thermogenesis on energy expenditure.if there is psychological stress energy expenditure increases.
It is mediated by stress hormones and can increase heart rate and respiration. - 54What are the 2 components of Cold-induced thermogenesis?Shivering - rhythmic muscle contractions
Non- shivering - adaptive thermogenesis - 55Give two examples of drugs which contribute to drug induced thermogenesiscaffeine, Nicotine
- 56Measuring energy expended as heat = ?Direct Calorimetry
- 57Calculating EE from other measurements that relate to heat production = ?Indirect calorimetry
- 58What are prediction equations?estimate EE from equations based on population measurements
- 59Explain how direct calorimetry is measuredsubject is placed in an insulated box
heat produced by the subject warms the area
temperature increase is measured - 60What are the different types of direct calorimetry?Isothemal
heat sink
convection
differential - 61Name 3 advantages of direct calorimetrysimple in theory
direct measurements
no conversion factors
accurate measurements
considered a gold standard - 62Name 3 disadvantages of direct calorimetrycomplex to operate in practice
expensive equipment
equipment rarely available
subject is restrained
time required for heat equilibration
only measures heat produced - 63What is indirect calorimetry based on?relationship between O2 uptake and CO2 production.
- 64What is collected in indirect calorimetry?inspired and expired air
- 65What are the types of indirect calorimetry?room calorimetry
metabolic cart
portable respiratory
doubly labelled water - 66Explain what is involved in the room calorimeter/ ventilated chambersealed well insulated room with bed, chair, table, air lock hatch for food, drink, urine and faeces.
air drawn through chamber at measured rate, O2 and CO2 measured entering and leaving, temp and pressure recorded, uptake of O2 and production of CO2 calculated. Then EE calculated using formula. - 67What are the advantages of the ventilated chamber?accurate
can measure TEE over 2-14 days
subject less restrained than other methods
provides data on nutrient metabolism as well as energy. - 68What are the disadvantages of the Ventilated chamber?complex to operate in practice
expensive
bulky equipment
subject is not free living
time required for gaseous equilibration
assumptions must be made in calculations - 69What is the metabolic cart?Custom- built trolley
incorporates O2 and CO2 analyser
mouthpiece/mask with tent/ hood
software involved
used in conjunction with bed or exercise bike. - 70What are the advantages of the metabolic cart?relatively easy to operate
portable
accurate enough for clinical/research purposes
measure over 0.25- 8 hours
health and sick individuals - 71What are the disadvantages of the metabolic cart?relatively expensive
subject is not free living
assumptions made in calculations
accuracy depends on good calibration - 72What does portable respiratory require?system to collect inspired/expired air
measurement of volume
analysis of O2 and CO2 concentration
calculation - 73What are the advantages of portable respirometry?cheap and easy to use
can use for physical activities
some portable - 74What are the disadvantages of portable respirometry?poor accuracy
rely on assumptions and calculations - 75What is the technique of doubly labelled water?subject drinks accurate dose of doubly labelled water
collect saliva/blood/urine sample for 2-3 weeks
plot graph of concentration to show loss
calculate rate of loss - CO2 production - energy - 76What are the advantages of doubly labelled water?measures TEE
free living subjects
blood sample not essential
considered gold standard - 77What are the disadvantages of doubly labelled water?relies on assumptions
isotopes expensive
compared with direct calorimetry +/- 7% - 78Explain the theory behind using a heart rate monitorsignificant relationship between heart rate and TEE
portable, small and non-restraining
measurements for 72 hours +
best for population studies - 79What are the advantages of the heart rate monitor?estimates TEE in free living individuals
accuracy is ok
useful for field studies/ large groups
reasonably cheap - 80What are the disadvantages of the heart rate monitor?if not individually calibrated accuracy is poor
not suitable for metabolic studies or accurate research - 81What are pedometers and accelerometers?portable devices that measure movement
- 82How do pedometers and accelerometers work?attach to body
enable collection of free-living date
usually require calibration
useful for measuring changes
useful for groups
less useful for quantifying EE - 83Name the 3 prediction equations for BMRHarris-Benedict 1919
Schofield 1985
Henry 2005 - 84What are the advantages of prediction equations?Cheap
quick and easy
equipment readily available
useful for a rough indicator
can be used to check other methods - 85What are the disadvantages of Prediction equations?Only predict REE
inaccurate
must be population specific
less accurate with individuals
least accurate in illness and disease