Nutrition Energy

Question 1

What BMI is considered underweight? Overweight? Obese?

Answer 1

19
25
30

Question 2

What is the best quantification of metabolism?

Answer 2

basal metabolic rate

Question 3

How is basal metabolic rate measured?

Answer 3

under standardized conditions with an overnight fast, isothermic temperature, supine position, etc.

Question 4

How is the resting metabolic rate different from basal metabolic rate?

Answer 4

it’s really similar, but it’s not standardized so it will differ from lab to lab

Question 5

What is the resting energy expenditure?

Answer 5

it’s the resting metabolic rate plus the thermic effect of fod - often estimates as RMR + 10% or RMR x 1.1

Question 6

What is total energy expenditure?

Answer 6

this is the resting energy expenditure plus any energy expended in physical activity, wound repair, etc.

Question 7

What do we typically multiple the REE by to get TEE for a sedntary adult? Healthy active adult? Adult recovering from trauma?

Answer 7

1. 2 for healthy sed
2. 4 for healthy active
3. 6 for recovering from trauma

Question 8

So what are the three components of human energy expenditure?

Answer 8

energy expenditure of physical activity
thermic effect of food
basal metaoblic rate

Question 9

How is metabolism measured directly?

Answer 9

using a bomb calorimeter where you basically burn things and see how hot it gets

Question 10

How does indirect calorimetry work (it’s so much more practical)?

Answer 10

You keep track of the volume of inspired and expired air and monitor the concentratiosn of O2 in and CO2 out

the comparison of this (CO2/O2) gives you the respiratory quotient, which can give you an idea of what fuel stores they’re using

Question 11

How can the RQ tell you what fuel stores they’re using?

Answer 11

Fat is the least oxidized (most saturated) fuel so it requires more O2 to use. Gives an R value of .7 because it takes more O2 than CO2

Carbs are the most oxidized fuels and will only need 1 O2 for each CO2, thus R value is 1

Question 12

What conditions will thus increase the R quotient?

Answer 12

hyperventilation
overfeeding
acidosis

Question 13

What conditions will decrease the R quotient?

Answer 13

hypoventilation
underfeeding
alkalosis
ketosis
ethanol

Question 14

So once you have the information of O2 liters inspired and CO2 liters expired from indirect calorimetry, how can you determine the basal metabolic rate?

Answer 14

The table will give you how many calorie equivalents per O2 and CO2 molecule based on the patient’s RQ

If you multiple this equivalent by how many liters of either O2 or CO2, you get the BMR

(they’ll be pretty close in agreement)

Question 15

Another way to dot his is just use the Harris-Benedict equation to calculate the BMR. What does it have multipliers for?

Answer 15

to account for physical activity or recovery from injury