2.17 Energy Balance

Question 1

What is energy balance

Answer 1

The relationship b/w energy into (food calories taken into the body) and out of (calories being used in the body for our daily energy requirements).

Question 2

Define the state of energy balance

Answer 2

Where energy intake is equal to energy expenditure

Question 3

Define the state of a negative energy balance

Answer 3

When energy expenditure is greater than energy intake

Question 4

Define the state of a positive energy balance

Answer 4

When energy intake is greater than energy expenditure

Question 5

How is energy intake calculated

Answer 5

It is calculated by the sum of energy from foods, fluids and supplements

Question 6

How is total energy expenditure calculated

Answer 6

(free living measurement) = basal metabolic rate + thermogenesis (cold induced and thermic effects of food) + energy expended in physical activity

expressed in Kcal/min or KJ/min

Question 7

Describe the thermodynamic law about energy

Answer 7

Energyis never created or destroyed, but is just transferred, the energy balance dictates whether weight is lost gained or constant

Question 8

What does potential energy stored within food go towards

Answer 8

Work, heat or storage

Question 9

What is the role of the central nervous system in energy balance

Answer 9

The CNS receives constant chemical input on the bodys energy state in order to maintain homeostasis of the energy balance

Question 10

What are the key components of regulating energy intake

Answer 10

• sensing an energy deficiency/abundance (regulated by hypothalamus)
• the gastric load (homeostatic mechanisms) (regulated by brainstem)
• salience of nutrients and incentive/motivational value of food (regulated by mesolimbic system)

Question 11

What are the areas of the brain involved in regulating food consumption

Answer 11

The hypothalamus, brainstem and mesolimbic system communicate with eachother to regulate food consumption

Question 12

Which factors influence energy expenditure

Answer 12

Energy expenditure is influenced by factors such as Heredity, Age, Gender, Body size, Fat-free mass Intensity/frequency/duration of exercise

Question 13

How much energy does 1g of fat provide

Answer 13

9.4kcal of energy

Question 14

How much energy does 1g of protein provide

Answer 14

4.3kcal of energy

Question 15

How much energy does 1g of carbohydrate provide

Answer 15

4.2kcal of energy

Question 16

What is the basal metabolic rate (BMR)

Answer 16

The rate at which body expends energy to sustain basic life processes and stay in an awake state

Question 17

Describe how BMR is calculated

Answer 17

-oxygen consumed and co2 produced used to calculate BMR

-BMR is then converted to Kcal/24hours and called basal energy expenditure

-BMR should be measured when subject has fasted for 12 hours, at complete mental and physical rest, supine and in thermoneutral temperatures

Question 18

What is a standardised measurement for BMR

Answer 18

Resting MR, but it has less strict measurement conditions such as only 4-6 hours of fasting.

Question 19

Describe the effects of exercise on energy expenditure

Answer 19

Exercise increases energy expenditure during, immediately after and long term after