NUTRITION
AIM
• To understand what our bodies need to
function effectively
• To understand how different ages and
lifestyles require different nutrition
Calories (or kilojoules) are a measure of the energy contained in both the foods we
eat and our body fat. Our bodies use the energy found in the food we eat to keep us
running, and store any excess as body fat for future use.
When we expend energy it is said that we are burning calories, and when we burn
more calories than we eat our bodies turn to our fat stores to find the additional
energy they require. Thus when we eat more calories than we burn we gain weight,
and when we burn more calories than we eat we lose weight.
Eat more calories than you burn and you will gain weight;
eat fewer calories than you burn and you will lose weight.
Adults require approximately 2000 calories per day.
20-50% of your calorific needs are determined by physical activity and the rest is
needed for breathing, circulating blood and keeping new cells functioning.
45-60% of your calories should come from carbohydrates
25-30% of your calories should come from fat
10-35% of your calories should come from protein
Fats and alcohol are by far the most energy-dense foods. This is why they should
only be consumed in moderation, particularly if you are overweight or obese.
1g fat = 9 calories
1ml alcohol = 9 calories
1g carbohydrate = 4 calories
1g protein = 4 calories
1g fibre = 3 calories
1ml water = 0 calories
WHO NEEDS WHAT?
Throughout life your nutritional needs will vary. They also vary depending on whether you are male or female the
kind of life you lead.
Babies – in the first 4 months breast or formula milk provides all the nutrients they need. After that the baby is slowly
weaned onto more solid, mashed foods such as cereals, vegetables and fruit.
Young children – need to take in more energy (in relation to their size) than they use because they are growing. They need
food high in carbohydrates, such as bread and cereals as well as a mixed, balanced healthy diet to provide them with all
the nutrients they need.
Adolescents – need a high-energy intake because they are usually very active and, as puberty sets in, growth and
development is accelerated.
Adults – their nutritional needs vary greatly depending on their age, gender,lifesyle and occupation. A less active person
will require less energy thana very active one. Both groups still require a balanced diet, but the energy intake will vary to
avoid obesity and health-related problems.
Older people – their energy requirements decrease as people become less active, but it is still essential that older people
continue to eat a balanced diet that is interesting and varied.