Energy Flashcards
How much does each factor of EE contribute to total EE
Basal - 60-65%
Physical - 25-35%
Ingestion of food - 10%
Components of EE
Basal metabolic rate
Physical activity
Ingestion of food
Thermogenic processes
Factors affecting EE
Body size Body composition Gender Age Diet Climate Genetics
How does body size affect ee
Larger body more cells more energy needed
Body composition
Adipose has lower metabolic rate
How does gender effect EE
Different body sizes an compositions
Age effects on EE
Decreases with age
Diet effects EE
Over feeding increases by 10%
Under feeding reduces by 10%
Climates effect on ee
Maintain body temp
Genetics on EE
10% variation for individuals with same gender age size and body composition
How does weight change occur
Differences in the balance if energy intake to expenditure
What does bomb calorimetery measure
Gross energy
Atwater factors
Protein 4
Cho 4
Fat 9
More factors effecting Ee
Psychological state
Pharmacological agents
Diseases
Measuring EE is useful for whom
Clinical application Obesity diagnosis Institutional feeding Sports nutrition Public health initiative
What is direct calorimetery
Measurement of heat given off by an individual
What are indirect methods
Energy intake versus weight overtime
Indirect calorimetery
Heart rate measures
Strengths of direct methods
Accurate
Highly reproducible
Weaknesses of direct methods
Expensive
Difficult
Unrepresentative
Strengths of energy intake vs weight over time
Non invasive
Ecologically valid
Easy
Weaknesses of EI vs weight
Errors in measuring EE
Errors in estimating body comp
Unreliable
What is indirect calorimetery
When foods are oxidised in the body O2 consumption and co2 production are proportional to heat generation
What are the respiratory quotients for cho protein and fat
Cho - 1
Pro - 0.818
Fat - 0.696
Why is the rq lower for fat
Because it contains more hydrogen and carbon atoms than oxygen
What principle is used for using heart rate to measure EE
Linerality between hr and O2 consumption
What is the gold standard indirect method
Doubly labelled water
What are the coefficients of digestibility for cho protein and fat
Cho- 97%
Protein - 92-75%
Fat - 95%
