The basics of nutrition and energy (Energy measurement (Average is 1.4,…
The basics of nutrition and energy
OUTPUT/EXPENDIITURE = ENERGY WE USE IN DAILY ACTIVITY
INPUT/INTAKE = ENERGY WE GET FROM FOOD
If we eat less than our body needs than the fat stores in our body are burnt as fuel and we may get thinner
If we eat more food than our body needs the excess is changed into fat
This is the correct amount of food that our body needs.
Average is 1.4
Very active = 1.7
Fairly active = 1.3
Inactive = 1.2 PAL
EAR = BMR X PAL
EAR (Estimated Average Requirements)
Our total energy needs are worked out by multiplying the BMR by the physical activity level: PAL
BMR for Women: 1300kcal
BMR for Men: 1600kcal
Basal Metabolic Rate or BMR is the amount of energy we need when the body is resting, this accounts for 2/3 of a persons daily energy needs
As we get older the amount of food we need changes
Eat the right amount to be a healthy weight
Too much energy from food and drink is stored as fat in the body
How much energy do we need??
It varies with:
Age eg children need energy for growth & activity
Gender - boys need more than girls
Body size - larger bodies need more energy
How active we are/ lifestyle
Energy and nutrients
Fat is said to be ENERGY-DENSE food since it provides a concentrated source of energy
1g fat provides (9kcal)
1g carbohydrate provides (3.75 kcal)
1g protein provides (4 kcals)
Food and drinks provide us with different amounts of energy because of the variety of nutrients they contain.
How is energy measured??
1 calorie = 4.2 kj
Energy is also measured in calories (kcal).
This is a different way of measuring energy, just as distance is measured in centimeters and inches
Energy is measured in units known as kilojoules (Kj)
How is energy converted in the body??
GLYCOGEN is broken down into glucose to produce energy
Energy can be used for activity immediately or it can be stored in the muscles and liver as GLYCOGEN
Glucose + oxygen = water, carbon dioxide & energy
We breath in oxygen and this is carried to the body cells
Glucose is carried to body cells by the blood
Carbohydrates is broken down into glucose
Why do we eat food??
We eat food because our bodies need:
compounds for growth, repair and reproduction
substances to regulate the production of energy, growth and repair
The energy supply
...provide the body with energy
Why so we need energy??
We need energy:
To make our muscles move and be active
To maintain body temperature
To carry out the body's functions eg breathing, heartbeat
For tissue growth and repair