Energy

Question 1

Gross energy (GE) represents

Answer 1

total calorific content of food, measured as the energy released when food is completely combusted in oxygen, producing carbon dioxide and water.

Question 2

This is typically quantified

Answer 2

using a bomb calorimeter

Question 3

While gross energy provides a measure of the total energy in foods, it overestimates

Answer 3

the actual energy available to humans because it does not account for energy lost during metabolism, which can vary significantly depending on the type of food and individual metabolic differences.

Question 4

Digestible Energy Equation:

Answer 4

DE = (E intake – Fecal E) / E Intake x 100

Question 5

Digestible energy considers the portion of gross energy that is actually absorbed by the body, after

Answer 5

accounting for the energy lost through faeces.

Question 6

The absorption rates of different macronutrients highlight the physiological efficiency of our digestive system

Answer 6

carbohydrates (~99%), fats (~95%), proteins (~92%), and alcohol (~100%).

Question 7

Metabolisable Energy:

Answer 7

ME = DE – (UE+GE)

Question 8

Metabolizable energy (ME) is what remains after deducting energy lost through

Answer 8

faeces and urine and gases from digestible energy.

Question 9

(ME) more closely reflects the

Answer 9

actual energy available for physiological functions like growth, repair, and maintenance.

Question 10

According to studies by Atwater, ME is adjusted

Answer 10

differential energy costs of nutrient metabolism.

Question 11

For instance, protein has a higher thermic effect, leading

Answer 11

to greater heat loss

Question 12

Scientifically, understanding these energy distinctions helps in formulating

Answer 12

diets and understanding metabolic disorders.

Question 13

For example, individuals with specific digestive or metabolic issues might require adjustments in their diet to optimise

Answer 13

the metabolizable energy they can actually utilise.