Food Groups, BMI and BMRBiology Revision Material
By: Zoe Allen
Food Groups
The different food groups all have different
uses in the body. We need the right balance of
food to keep us healthy.
 Carbohydrates release energy
 Fats insulate, and release energy
 Protein is for growth, cell repair and cell
replacement
 Fibre is good for the digestive system
 Vitamins and mineral ions help keep
everything generally healthy e.g. calciumbones and teeth etc.
BMR
We need energy to
fuel the Chemical
Reactions that take
place within the
body that allow us to move and keep us
alive. The chemical reactions are called
metabolism; the speed of which they occur
is called metabolic rate. BMR stands for
Basal Metabolic Rate.
BMR
There are variations in
peoples metabolic rates,
because we are all different.
Some factors effecting metabolic rate are:
 Proportion of fat to muscle in the body, as
muscle needs more energy than fatty tissue.
This means that people with a higher
proportion of muscle to fat in their bodies
will have a higher metabolic rate.
 Gender, as men have a higher proportion of
muscle to women.
BMI
BMI stands for Body
Mass Index.
It is an equation which
tells you whether you
are over weight or under weight:
BMI = mass in kg ÷ (height in m)²
For example:
What is the BMI of a 1.7 m person with a
body mass of 60 kg?
BMI = 60 ÷ (1.7)² = 60 ÷ 2.89 = 20.8
BMI Table
This table summarises the meanings of
different BMI calculations.
BMI
meaning
Under 18.5
Underweight
Between 18.5 and 24.9
Normal
Between 25.5 and 29.9
Overweight
Between 30 and 39.9
Obese
Over 40
Very Obese
Revision Questions
1.
2.
3.
4.
5.
Name all the food groups you need to eat
to have a balanced diet.
Put these jobs in order of how much
energy they would need from their food
(highest to lowest) a)mechanic,
b)professional runner, c)secretary?
What does BMR stand for?
What are the chemical reactions called
within the body?
What is the BMI of a 1.4m person with a
body mass of 57kg?
Answers!
Carbohydrates, fats, Proteins, Fibres,
Vitamins and mineral ions.
2. Professional runner, mechanic, secretary
3. Basal Metabolic Rate
4. Metabolism
5. 57÷(1.4)²= 29.1
(Overweight)
1.