Lecture 1

Question 0

1 Gram of CHO/Fat/Protein/ Ethanol is equal to how much Kj/g & kcal/g?

Answer 0

CHO: 16.7 kj/g (4 kcal/g)
Protein: 16.7 kj/g (4kcal/g)
Fat: 38.1 kj/g (9 kcal/g)
Ethanol: 29.3 kj/g (7 kcal/g)

Question 1

How might energy intake be measured?

Answer 1

Direct Calorimetry - Bomb Calorimeter

Question 2

1 kcal = ?? Joules

Answer 2

1 kcal = 4.18 Joules

Question 3

How much of protein is nitrogen and what happens to it?

Answer 3

15-19%, which is excreted and does not contribute to EI

Question 4

What is the difference in soluble and insoluble fiber when ingest in terms of energy intake? How does this effect food labels?

Answer 4

Soluble can be partially fermented/broken down while insoluble cannot be broken down which means it does NOT contribute to EI while soluble fiber may contribute a minor amount. Each country interprets the contribution of soluble fiber differently so depending on the country your food label will read differently for energy contribution of soluble fiber.

Question 5

What limitations are associated with Energy Intake (EI) estimates (3)?

Answer 5

• Energy availability (EA) may change depending on specific food compared to “Antwater” factors
• Mixed/cooked meals does not equal the sum of its individual parts
• EA may change depending on other factors such as Obesity, Gut Microbiota, disease etc

Question 6

From an EI perspective does it matter if Cal are absorbed from Fat or CHO?

Answer 6

Long term may affect RQ but short term “calories are calories”

Question 7

Will you ever deplete the body of CHO and glucose?

Answer 7

Likely not as CHO is the main fuel source for the brain and body. Regulation of CHO and glucose is primary concern.

Question 8

What happens to insulin once food (CHO) is ingested, what happens to oxidation of Fat and CHO?

Answer 8

Once CHO is ingested, Insulin is secreted.
Body will begin digesting and utilizing the CHO.
CHO oxidation (RER 1.0) increases while Fat oxidation (AKA lipolysis) (0.7) decreases

Question 9

Does increasing fat consumption increase fat oxidation?

Answer 9

No it does not.

Question 10

What happens to excess CHO that does not get oxidized?

Answer 10

Stored as fat

Question 11

Describe the Oxidative Hierarchy

Answer 11

This is the order of utilization/oxidization of the macronutrients +alcohol. Alcohol, CHO, Protein, Fat which means that Alcohol is oxidized before all others, CHO before protein/fat etc.
The one catch is that if the body is in need of CHO it will preserve the CHO it has and begin utilizing Protein/Fat first. Regulation of Macronutrients supersedes the hierarchy of oxidation.

Question 12

How do we measure TDEE?

Answer 12

Double Labeled Water or estimate RMR + TEF + EEA

Question 13

What is RMR and how do we measure it?

Answer 13

Resting Metabolic Rate - The basic energy required to survive
Can be measured directly (bomb) or indirectly by measuring inspired and expired gas (VCO2/VO2)

Question 14

What is the RER of Lipid oxidation?

Answer 14

0.7

Question 15

What is the RER of CHO oxidation?

Answer 15

1.0

Question 16

What can influence RMR?

Answer 16

Body temp, Posture, Food consumed, level of alertness, time of day

Question 17

What should be the test conditions for the subject when measuring RMR?

Answer 17

Rest them supine
Room should be temperature neutral
Fasted over night 
Be awake during test
No exercise w/in 12 hours
Female: Controlled phase of menstrual cycle

Question 18

Who will have higher metabolic rate?
Male/Female
Young/Old
Fat/Normal

Answer 18

Male
Young
Fat

Question 19

Explain the relationship between RMR and Body weight and how does this apply to the 3500 kcal/ 1 pound of fat rule in the Hall et al. reading?

Answer 19

RMR is the minimum amount of energy needed to survive, a larger body will require more fuel to perform activities (compared to a smaller person) because it takes more to move a larger mass. Inversely it will cost a smaller person less energy to do the same thing as a larger person. As a body loses weight, the amount of energy to perform certain activities will also drop. This means that a person may have to perform more activity or take in less energy to lose weight at the same rate throughout an intervention. This means the 3500kcal rule should not be applied throughout the WHOLE intervention and may only be useful at one phase.

Question 20

What could influence the accuracy of RMR?

Answer 20

• Last bout of exercise (EPOC)
• Last meal (Diet Induced Thermogenesis)
• Rested state
• Low grade infections
• Tester accuracy
• Equipment accuracy
• Other factors (stress, sleep, etc)

Question 21

What are the effects of ACUTE or CHRONIC physical activity on RMR?

Answer 21

Chronic: (Similar to the 3500kcal theory) Chronic PA changes FM and FFM which influences RMR. This means RMR is variable.

Acute: Single doses of exercise can raise EE due to variability in exercise (FITT) and sustained after effects due to (EPOC)

Question 22

RMR is effected more by Skeletal muscle or visceral organs?

Answer 22

Visceral organs, which actually account for 60% of RMR

Question 23

What can increase EPOC and what allows for more energy expenditure, the actual exercise or EPOC?

Answer 23

EPOC can be varied by time and intensity of exercise, but in the end the actual exercise itself is responsible for most of the EE.

Question 24

How long does EPOC last?

Answer 24

48 hours

Question 25

What would happen to your RMR if you entered a negative energy balance? What might happen if you entered a positive energy balance?

Answer 25

If you enter a NEGATIVE RMR the body may interpret this a bad and decrease your EE by decreasing RMR in order to conserve energy. Inversely, if you enter a POSITIVE RMR the body would increase RMR. Same way obese people have an increased RMR.

Question 26

What is DIT (aka TEF?)?

Answer 26

Diet Induced Thermogenesis (Thermic Effect of Food) - the energy needed for digestion, absorbtion, and storage.

Question 27

What happens to DIT if dieting restricts calories consumed? What would happen to DIT and conversely TDEE if more protein is consumed in the diet without increasing more caloried?

Answer 27

Reduction in Calories means a decrease in DIT because there is less to absorb/oxidize. But if the calories stayed the same but protein increase while fat decreased this would theoretically increase the amount energy required for digestion thus increasing DIT and TDEE

Question 28

What % of total calories are lost to DIT?

Answer 28

~10% of total calories are lost to DIT

Question 29

What is EEA?

Answer 29

Energy Expenditure for Activities - this includes workouts, exercise, PA, NEAT, EPOC

Question 30

What is NEAT?

Answer 30

Non Exercise Activity Thermogenesis - occupation, leisure, sitting, posture, ambulation, fidgeting ANYTHING OTHER THAN: Sleeping, Eating, Physical Activity

Question 31

What is PAL?

Answer 31

Physical Activity Level - ratio of TDEE:RMR

Question 32

How would exercise effect NEAT?

Answer 32

a decrease in body weight means it requires less energy for the same movements. Efficiency of movement may also increase, making the cost of EE for a movement less.

Question 33

What would happen if NEAT increased on a person but Cal intake did not change?

Answer 33

Person would see a negative energy balance compared to pervious level meaning a decrease in body weight if the overall energy balance was negative.

Question 34

How many Joules in 100 Cal?

Answer 34

418 joules in 100 Cal