Energy Balance Write down FOUR factors which contribute towards a healthy diet.

How many did you get right?  Eat a variety of foods  Eat a well balanced diet  Eat five portions of fruit and vegetables a day  Exercise regularly

OBJECTIVES  Understand the different uses of energy in the body  Describe the factors affecting energy requirements.  Define the concept of a balanced diet

Food provides energy So the following can occur:  Growth  Repair  Maintenance of the body Energy is measured in Kcal or K joules

Four Types of energy  Mechanical, muscles performing basic functions.  Chemical energy is respiration, when cells release energy from food.

Chemical Energy  Chemical energy is better known as respiration.  This is when a chemical reaction allows cells to release energy from food.  Metabolic rate is the speed which this occurs.

Heat Energy  Your body takes chemicals from food you eat and turns them into energy.  Heat is generated when this breakdown occurs.

Electrical energy  This is energy used by the nervous system.  Your sense organs contain receptors.  They create electric impulses used for reflex reactions.

Daily Energy requirements = BMR +  Basic metabolic rate.  Number of calories you need to stay alive.  This can vary between people PAL  Physical level activity  Number of calories required to fuel physical activity  Dependent on the sports or activity you do

Energy balance = Energy input + Energy output

Test your understanding Can you describe what is a balanced diet using the following words?  Energy input  Energy output  Kilo calories  BMR

Different energy requirements Youngold

Metabolic differences FemaleMale

Occupation Sedentary jobActive job

Life stage PregnancyConvalescence

Explain yourself  In pairs you need to discuss and identify three factors which affect our energy requirements. Try and include the correct terminology in your answer.

How are energy requirements measured?  DIETARY REFERENCE VALUES (DRVs) are estimated requirements on population groups.  ESTIMATED AVERAGE REQUIREMENTS(EARs ) is an average estimate for a certain group of people e.g. toddlers  LOWER REFERERENCE NUTRIENT INTAKE (LRNI) is an estimate for a group of people with low energy requirements e.g. the elderly.