Zusammenfassung der Ressource
Yr9 Biology - Diet & Exercise
(GCSE AQA B1.1.1)
- A healthy diet contains the right balance
of different foods you need and the right
amount of energy
- Carbohydrates
- gives you energy and build cells
- sugary + starchy food - potatoes, rice,
cereals, pasta, bread, some fruit and veg
- Fats
- provide energy and help in
building cell membranes
- dairy, red meats, some poultry and fish
- Minerals
- bodily functions
- iron is good for the blood as its a component a
substance that carries oxygen around the body
- calcium is good for improving
the strength of your bones
- fresh fruits, veg
- Vitamins
- good for keeping body healthy - skin, bones and teeth
- vitamin c helps to make collagen which heals wounds, supports
blood vessel walls and forms a base for teeth and bones
- dairy products, fresh fruit, veg
- Proteins
- help body grow, repair itself,
release energy and build cells
- meats, poultry, fish, dairy, eggs, beans
- Fibre
- helps you digest food and provides
bulk to move food along you tract
- cereals, fruit, bread, veg
- Water
- essential for most chemical reactions,
keeps body temp. normal, lubricates
and cushions joints, protects spinal
cord and sensitive tissue and gets rid
of waste through urination,
perspiration and bowel movements
- MALNOURISHED = not balanced diet
- leads to being underweight or overweight
- overweight - leads to Type 2 diabetes, heart
disease, arthritis, high blood pressure, cancers
- underweight - leads to organ failure, lack of resistance
to infection, deficiency disease, irregular periods
- Energy Content
- Energy input > Energy output = gain weight
(positive energy + additional energy stored)
- Energy input < Energy output = lose weight
(negative energy + used to meet demand)
- Energy increase the amount of energy used by the body
- CALORIES (kcal) = indicator of energy content of food
- Measure energy in kilo/joules (k/j)
- METABOLIC RATE = rate
of chemical reactions in
cells
- affected (if high) by amount of exercise (very active),
size(bigger=more cells=more cell reactions), environment
(climate --> altitude=more sweat), genetics, fitness levels,
gender (males higher because % muscle tissue to fat is
higher), overweight, age (higher if young)
- CHOLESTEROL = an insoluble substance which we make in our
liver from saturated fats (or eggs, meat and dairy) that gets carried
around the body in our blood
- Needed in body for cell membranes, steroid hormones
(testosterone), some growth hormones, bile salts
- When cholesterol is encased in proteins to be transported around the body, it is called lipoproteins (soluble)
- LDLs = low-density lipoproteins, known as 'bad' cholesterol, raised levels increase risk of heart problems
- takes cholesterol around the body in the blood to cells from liver --> creates build up on lining of arteries
- Factors that increase LDL levels
- Age - over 50s
- Gender - Male
- Smokers
- Type 2 diabetics
- Overweight/Obesity
- Genetic predisposition - family history of heart disease
- Lowering LDL levels
- lower intake of saturated fats -->
causes accumulation of LDL
- increase intake of monounsaturated fats -->
lowers cholesterol a little
- increase intake of polyunsaturated fats -->
lowers cholesterol a lot
- HDLs = high-density lipoproteins, known as 'good' cholesterol, reduces risk of heart disease
- takes excess cholesterol back to the liver --> reduces build up on lining of arteries
- Avoid increasing risk of CardioVascular Disease by
maintaining low levels of LDLs and high levels of HDLs
- SATURATED FATS increase blood
cholesterol levels and are in meat,
butter and cheese
- POLY-UNSATURATED FATS even better at reducing
cholesterol levels and balancing HDL and LDL levels
than mono-unsaturates. Found in corn oil, sunflower
oil, margarines and oily fish
- MONO-UNSATURATED FATS have two useful
effects: reduces overall blood cholesterol levels
and improves HDL and LDL balance. Found in
olives, olive oil, peanuts and margarines