Energy Intake and Balance Flashcards
What is nutritional balance?
When intake = losses
What is positive balance?
When intake is greater when losses
What is negative balance?
When losses are greater than intake
Give 5 examples of Non-degradable nutrients
Nitrogen
Iron
Energy
Calcium
Sodium
Give 5 examples of Degradable nutrients
Protein
Fat
Carbohydrates
Fibre
Vitamins
What is 1 kilocalorie (kcal) the same as in kilojules (kj)
4.184
What are the Atwater factors for carbohydrate, protein, alcohol and fat? Give units
Available Carbohydrate = 3.8 kcal/g
Fibre = 1.9 kcal/g
Protein = 4 kcal/g
Alcohol = 7kcal/g
Fats = 9kcal/g
True or False, do all foods we eat become absorbed?
False
Why is Energy so importnat?
Energy is required for anything to happen in the universe
Energy is essential for all life processes
Energy cannot be created or destroyed only transferred between different energy stores
Name 5 types of energy
Heat
Light
Chemical
Kinetic
Electrical
What are the units for energy?
Joules (J) and Calories/ Kilocalories cal/Kcl
What is 1 calorie equivalent to in kj?
1 kcl = 4.184 kJ
What is 1 megajoule (MJ) equivalate to in joules (J)
1 megajoule (MJ) = 1,000,000 joules (J)
Total energy from different macronutrients the same, but why may this not be the case?
Metabolism within the human body is different
Energy concentration is different (i.e. volume)
Nutrient value is different
How is a bomb calorimeter used with food samples, what is its accuracy?
Models use for food and environmental samples
Samples homogenised and dried
Accuracy +- 1%
How do we you calculate digestible energy?
Digestible energy (DE) = Gross Energy (GE) - Faecal energy
Is all digested energy metabolised?
Yes - fats, carbohydrates and alcohols
No - Proteins
How is metabolised energy calculated?
Metabolised Energy = Digestible energy of fat - Digestible energy of carbohydrates + 90.75 X digestible energy of protein)
ME = DE fat - DE Carb + (0.75 x DE protein)
What percent approximately is metabolised energy (ME) equal to Gross energy (GE)?
84%
Why does the percent metabolised energy = gross energy of 84% vary?
Variations due to macronutrient content
Metabolised energy is what body uses
Atwater figures provide metabolised energy
Food tables provide metabolised energy
How is net metabolised energy calculated?
Net metabolised energy = metabolised energy - difference in heat energy
NME = ME - ΔHE
What is ΔHE?
ΔHE is the difference in heat energy expenditure when subjects replace available carbohydrates with another substances which leads to revised atwater factors
How is respiratory quotient calcualted?
RQ = CO2 / O2
What is a balanced diet?
A diet that provides neither too much or too little of the nutrients and other components of food that are required for normal functioning of the body
A balance between supply and demand
A diet that provided a varied nature in proportions such that foods rich in some nutrients do not limit intakes of food rich in others
What are examples of supplies our bodies have to meet demands, where do they come from?
Food
Drink
Air - Lungs
What are examples of demands of the body?
Breathing
Movement
Sleep
Minerals
Vitamins
What are examples of outputs of our bodies?
Faecal losses - Gut
Urine - Bladder
Other body fluids (sweat) - skin
Air - Lungs
What terms are used instead of input and output?
Intake and Losses
What 3 things does the concept of balance dependent on?
Nutrients
Time
Health
How log does it take to measure nutritional balance?
Depends on what nutrient you are considering
Examples:
Sodium intake = 24 hours
Vitamin D = A few months
Will the nutritional balance be for the following people be positive, negative, balance or more than one?
3- month old baby
School children
Athlete in training
Pregnant woman
Woman breast-feeding
Obese adult
Elderly person
3- month old baby = Positive
School children = Positive
Athlete in training = Positive
Pregnant woman = Positive/Balance
Woman breast-feeding = Positive/Balance
Obese adult = Negative
Elderly person = Balance/ Positive
