Diet and Digestion
Learning Objectives:
• To understand the main parts of the human diet.
Starter:
• What did you have to eat yesterday?
• Is what you have eaten good for you?
Why do we need a balanced diet?
Food provides us with the energy and materials required for: growth development repair reproduction
What is a balanced diet?
We need the right amounts of nutrients in balance to maintain good health and organ functions.
Food provides us with energy to: maintain healthy weight have a strong immune system be healthy enough to work and learn be happy
The Seven Food Groups
Carbohydrates
Water
Protein
Vitamins
Minerals
Fibre
Fats
Nutrient Role in Body Examples
Carbohydrates
Lipids
Proteins
Vitamins
Minerals
Fibre
Water
Carbohydrates
Carbohydrates give you energy. We usually talk about 2 types of
carbohydrates: simple - sugars complex - starch
Lipids (Fats)
Used to make cell membranes Stored to insulate organs - protection &
keeping warm Source of energy Essential for fat-soluble vitamins (A, D, E) Some make prostaglandins & hormones Long-chain omega-3 fatty acids in fish oils
protect us from heart disease
Proteins
Use to make enzymes, hormones, antibodies, haemoglobin, muscles, cells membranes, collagen and elastin in connective tissue, bone.
Used for growth and repair of tissues.
VitaminsRole in Body Examples of Foods
B group - coenzymes, aid processes eg respiration
cereals, wholemeal bread, leafy greens
A - dim-light vision, epithelial tissue, immune system
liver, green veg, orange fruit & veg
C - helps make connective tissue & absorb Fe in food
citrus, blackcurrants, kiwi fruit, peppers, potatoes
D - helps absorb Ca & deposit it in bones, protects against cancer & heart disease
oily fish, eggs, liver, made in skin when exposed to sunlight.
A,C,E - antioxidants, protect DNA & against cancer & heart disease
E: nuts, wholemeal bread
MineralsRole in Body Examples of Foods
Fe - making haemoglobin red meat, spinach
Ca - hardens bones & teeth, helps blood clot, nerve conduction, muscle contraction
milk, cheese, yoghurt, broccoli
Na & K - nerve conduction & heart function
Na: table salt
K - bananas
P - make cell membranes & ATP for bones
cheese, pork, tuna, nuts
Mg - bones green veg
I - thyroxine table salt, seafood
Zn - insulin meat, cereals, nuts, milk
Fibre
Indigestible plant matter, such as cell walls - adds bulk to food and takes up water in the gut. Helps us pass faeces easily.
Soluble fibre helps lower blood cholesterol levels
Water
Makes up 70% of us - blood plasma is 90% water.
Needed for transport in the body. Needed for sweat, tears and urine.
Superfoods
Some foods have been described as super foods, they are rich in several nutrients
Suggest why super foods are good for you and what effects they may have?