# P3/P4

Télécharger la présentation

## P3/P4

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
##### Presentation Transcript

1. P3/P4 Energy Expenditure/ Energy Balance

2. Assessment Criteria

3. Energy intake and Expenditure • It can be measured in either calories and joules. One calorie is defined as the amount of energy, or heat, needed to raise the temp of 1 litre of water by 1.c. In Britain we use calories, but should be referred to as Kilocalories or Kcal. The international unit for energy is joule or kilojoule 1kcal= 4.2 joules

4. Amount of Energy in foods • 1g carbs = 4 Kcals • 1g Proteins = 4 Kcals • 1g fat = 9kcals

5. Body Composition • The body is composed of two elements: • 1. Lean body tissue (ie. Muscles, organs, bones, blood) • 2. Body fat (or adipose tissue) • The proportion of these two components in the body is called body composition • This is more important than total weight

6. Calorimetry • This measures you’re BMR • Calorimetry is the science of measuring the heat of chemical reactions or physical changes. • Calorimetryinvolves the use of a calorimeter.

7. Direct Calorimetry • Directly measures energy produced by combination of food with oxygen • Involves the burning of food in a controlled way, and measuring heat energy produced • Heat energy is measured by observing the rise in temperature of a quantity of water heated by the burning food. • Alternative: Measure body’s heat production in a calorimeter chamber • The heat energy created by the subject radiates to the walls and heats the water. • Temperatures of incoming and outgoing water and air are recorded and used to calculate BMR and total energy expenditure.

8. In-direct calorimetry • Uses the fat that every atom of carbon in food combines with a molecule of oxygen during the chemical reaction to produce one molecule of carbon dioxide and release a definite and constant amount of energy. • Method involves the measurement of the amount of oxygen consumed – which can therefore be related to the amount of energy released by food

9. How much Energy (food) do you actually need? • Basal Metabolic Rate (BMR) is the minimal caloric requirement needed to sustain life in a resting state. This is the amount of energy that your body requires if you slept and rested all day. A variety of factors impact this affect the BMR, some speed it up and some slow it down they are; Body size: taller heavier individuals need a higher BMR to fuel them Growth: Children and Pregnant women need a higher BMR If you are ill (high temp) or stressed, you also require a higher BMR Age: The older you get the less you require Muscle mass: The more you have, the higher the BMR as lean tissue needs more energy that fat