Energy

Question 1

H

What are the 3 componets of energy expenditure?

Answer 1

• Basal Energy expenditure
• Thermic Effect of Food
• Energy Expenditure of Physical activity

Question 2

What other factors impact energy expenditure>

Answer 2

Cold adaption, medications, and emotions

Question 3

Describe what BEE is

Answer 3

The energy needed at complete rest. When you first wake up in the morning

Question 4

What percentage of total daily expenditure is BEE?

Answer 4

60%

Question 5

What is the difference between RMR and BEE?

Answer 5

RMR is a bit higher because it includes sedentary activities

Question 6

Describe TEF

Answer 6

The energy needed for digestion, absorption and storage of food

Question 7

How much of the daily expenditure is TEF?

Answer 7

5-15%

Question 8

Describe what EEPA is?

Answer 8

The sum of all physical exercise

Question 9

What is included in EEPA?

Answer 9

Exercise activity thermogenesis ( planned exercise) and non-exercise activity thermogenesis

Question 10

What is the direct way of measuring energy expenditure?

Answer 10

You would measure the changes in body temperature (heat production)

Question 11

Why would you measure body temperature in the direct way of getting energy expenditure?

Answer 11

Due to the inefficiencies of of the body systems, it produces heat which can be measured

Question 12

What are the indirect ways of measuring energy expenditure?

Answer 12

Oxygen consumption as a marker of heat production and doubly labelled water

Question 13

Why do we measure oxygen consumption when we are measuring energy expenditure?

Answer 13

Oxygen is a marker of heat production. The body does not store a lot of oxygen (hence us breathing constantly). Most aerobic reactions use oxidative substrates for heat production (energy).

Question 14

What does a respiratory quotient represent?

Answer 14

CO2 produced / O2 consumed

Question 15

Explain doubly labelled water as a measure of energy expenditure.

Answer 15

Ingest 2 labelled isotopes 2H2O18, O18 will leave as CO2 and H2O. difference between the 2 isotopes + total water pool. Unlabelled CO2 from oxidized fuel

Question 16

Do you need to measure TEF, why or why not?

Answer 16

No, because TEF is very similar for everyone

Question 17

How much variance is there in BEE/RMR?

Answer 17

> 80%

Question 18

What contributes to the variance in BEE/RMR

Answer 18

Free fat mass and to a lesser degree age and gender

Question 19

Food restriction results in…

Answer 19

decreased BMR

Question 20

How would you find PAL

Answer 20

TEE:BEE

Question 21

What can effect TEF

Answer 21

overeating and undereating

Question 22

Why is there variance of TEE in people the same size?

Answer 22

80% of BEE is accounted for by body size, so when people are the same size the varience is due to NEAT

Question 23

What 2 factors account for the variation of NEAT?

Answer 23

Evironmental (egocentric) - My sedentary activities, job transport
Biological (geocentric) - walkways, office fitness, walk clubs

Question 24

Energy Balance =

Answer 24

Maintence of energy stores

Question 25

What energy stores are depleted during short term?

Answer 25

Glycogen reserves (24hr) and some fat

Question 26

What stores are depleted during long term fasting?

Answer 26

Protein and fat catabolism

Question 27

what factors impact body energy balance

Answer 27

Compostion of tissue mass gained or lost, impact on enerfy expenditure (lean mass vs fat) and intake (type of fuel)

Question 28

Nutrient and Energy Balance achieved when intake =

Answer 28

body's rate of oxidation of each macronutrient

Question 30

What are our afferent signals?

Answer 30

Inputs, peptides, hormones and vagal afferent send signals to the controller CNS

Question 31

What are our efferent signals?

Answer 31

Outgoing signals from the CNS, they are going to adjust our food intake and energy expenditure in order to keep energy balance

Question 32

What are the CNS Afferent signals for control of energy

Answer 32

Short term meals and long term storage (adiposity)

Question 33

How do efferent signals respond ?

Answer 33

Hunger, energy expenditure, energy portioning, growth and reproduction

Question 34

What is the short term physiological response (general) to food intake?

Answer 34

1. Gut signal - stretch receptor and chemical (peptides from GI tract) —> act with GI peptides to reduce meal size and lengthen inter-meal satiety 2. Meal related CNS signals (quality and quantity of the meal) different hormones released which the hypothalamus is sensitive to based on blood concentrations of aa, glucose, fatty acids. Negative feedback 3. Information collected by brain stem ( Nucleus of solitary tract), sent to hypothalamus with other meal signals

Question 35

If we have so many hormones to suppress eating, why do we still over eat?

Answer 35

Override the signals, overeating

Question 36

What are the long term adiposity signals?

Answer 36

Lepton is secreted proportionally to the adipocytes, to decrease hunger and increase energy expenditure Insulin secreted by the beta cells of the pancreas, so increase in food availability = more insulin = reduced appetite

Question 37

Explain insulin resistance

Answer 37

When more insulin is released for the same effect on the body

Question 38

How does the CNS converge the long term and short term signalling?

Answer 38

• Meal-derived signals(short term) collated by Nucleus of the Solitary Tract (Brain-stem) NTS. • Short and long-term signals collated by paraventricular nucleus (PVN) located in the ventromedial hypothalamus (VMH) • Lateral Hypothalamus (LH);stimulates feeding (ghrelin) • Arcuate Nucleus(Arc)in hypothalamus converges adiposity signals (eg insulin and leptin receptors)

Question 39

What is the regulation of food intake (via leptin and insulin) during energy surplus?

Answer 39

Increased leptin and insulin = + POMC (in arc) -> increased alphaMSH + decreased AgPR—> MC4T -> + anorexgenic = decreased NPY and AGRP —> - Y1R + Y5R —> - orexgenic = decreased food intake and increased energy expenditure

Question 40

What is the pathway for decreased food intake via leptin and insulin?

Answer 40

Decreased leptin and insulin = - POMC (in arc) -> decrease alphaMSH + increased AgPR—> MC4T -> - anorexgenic = increased NPY and AGRP —> + Y1R + Y5R —> + orexgenic = increased food intake and decreased energy expenditure

Question 41

Explain metabolic syndrome?

Answer 41

Aka syndrome x or insulin resistance. Describes individuals that are more than just obese and have increased risk of CVD and diabetes

Question 42

How much heat is lost due to biochemical ineffiencies of converting to ATP?

Answer 42

60%

Question 43

How are water soluble nutrients transported?

Answer 43

enter directly into capillaries, feeding the portal vein (directly to liver)

Question 44

How are lipid souble transported

Answer 44

transported via chylomicrons into lymphatics * CMsvtoovlarge to enter blood capillaries \ enter lymphatic capillaries via fenestrations of lacteals; eventually enter blood circulation via lymphatic vessels (thoracic duct)

Question 45

What has a RQ of 1

Answer 45

glucose

Question 46

what is the consequence when ingestion is greated than oxiadation of macronutrients

Answer 46

increase in energy stores

Question 47

What is the hierachy of oxidation

Answer 47

alcohol > protein > glucose > fats

Question 48

What hormone signals a hunger response

Answer 48

Ghrelin