Energy balance and substrate metabolism Flashcards
How can energy balance be altered?
Changing energy intake or expenditure
Positive energy balance?
More in than out
Negative energy balance?
More out than in
How to increase energy balance?
Increase intake/decrease expenditure
How to decrease energy balance?
Decrease intake/increase expenditure
What components of energy intake are there?
Carbs, fat, protein, alcohol
Components of energy expenditure?
Resting metabolic rate (RMR), dietary induced thermogenesis (DIT), Physical activity energy expenditure (PAEE)
What is RMR?
Resting metabolic rate–> the energy needed to keep us alive
What is DIT?
Energy used to digest, absorb and metabolise the food we have eaten
What is PAEE?
Energy used by muscles when they produce force
Two main energy stores?
Carbs and fat
Which energy store can store more energy (fat or carbs)?
Fat
Where can fat be stored?
Blood, muscle and adipose tissue
Where is the largest method of storing fat?
Adipose tissue
How much fat (in kcal) can be stored?
> 100,000
Where can carbohydrates be stored?
Blood, muscle, liver
Where is the largest carbohydrate store?
Muscles
In what form is the largest carbohydrate store kept?
Glycogen
What is the relationship between endurance training status and amount of muscle glycogen that someone can store?
More endurance trained means ability to store more muscle glycogen
How much carbs can the body store?
3200 kcal
What is denovolipogenesis?
Conversion of non-fat sources to fat
What happens if you have more than 3200kcal of carbs?
Denovolipogenesis
What is leptin?
A hormone
Role of leptin?
Regulates appetite
What is the result of someone with leptin deficiency?
They gain a lot of non-lean body mass
What kind of tissue releases leptin?
Fat tissue
What happens to leptin secretion as a result of an increase in fat?
The fat tissue releases more leptin
Cause of leptin deficiency?
Mutation in gene sequence coding for the leptin protein
Main issue with measuring energy intake?
Observation effect–> when you know someone is observing you you modify your behaviour,
reporting bias–>sometimes people underreport what they consume,
participant recall–> people forget what theyve eaten