Food and Health.


Balanced diet- a diet which gives the correct amount of all the nutrients necessary for optimum health.

Malnutrition- from not enough food, malabsorption, unbalanced diet.

Obesity- being 20% over the reccomended body weight. Can increase the risk of type 2 diabetes, high blood pressure, coronary heart disease.

BMI=body mass (kg) / height (m^2)

Coronary Heart Disease:

Result of reduced blood flow to the heart, causing chest pain and heart attacks. Result of athersclerosis (narrowing/hardening of coronary arteries) due to presence of atheromas.

Low density lipoproteins raise blood cholesterol level as they transport cholesterol from the liver to the blood, where it circulates. A diet high in saturated fat increases low density lipoproteins, and this cholesterol increases the build up of cholesterol in the artery walls where they have been damaged.

High density lipoproteins lower cholesterol level as they traansport it from body tissues to the liver to be recycled/excreted. 

Salt can cause high blood pressure, which carries an increased risk of damage to artery walls, which have a risk of atheroma formation --> atherschlerosis --> CHD.

Increasing Food Production:

Increase human food supply by modern farming techniques eg antibiotics, selectibe breeding, fertilisers, and pesticides.

Fertilisers are chemicals that increase crop yield by providing minerals that plants need to grow eg phosphate, potassium, nitrate. Natural fertilisers are organic matter eg manure, artificial fertilisers are inorganic eg contain pure chemicals such as ammonium nitrate.

Pesticides are chemicals that increase crop yield by killing pests that feed on the crops, so less crops are destroyed/damaged. They can be specific or broad.

Antibiotics- animals for food given antibiotics to increase food production.

Advantages: Animals have more energy to grow, anitbiotics promote growth eg influence bacteria in the gut, less likely bacterial diseases to pass to humans.

Disadvantages: Increase likelihood of antiobiotic restistance, natural/good bacteria could be killed, antibiotics may be present in products eg milk.

Selective breeding involves selecting organisms with useful characteristics and breeding them together for many generations. 

Advantages: It can produce high yields, can produce organisms with increased resistance so farmers can use fewer drugs/pesticides, could be bred for increased tolerance eg weather conditions.

DIsadvantages: Cause health problems, reduces genetic diversity due to inbreeding, so small gene pool so population is more susceptible to disease.


Advantages: Quick production, environment can be artificially controlled, optimum conditions are easy to create, useful in a range of foods eg bread, wine, yoghurt, lasts longer in storage than raw product.

Disadvantages: High risk of contamination as optimum conditions for harmful microorganisms, small changes in temperature/pH can kill microorganisms, might not taste as good natural food.

Food spoilage- the deterioration of a food's characteristics, due to the growth of unwanted microorganisms, which secrete enzymes to break down the substance. Young and elderly are more likely to be affected by food poisioning as they have a weaker immune system.

Salting-inhibits growth of microorganisms by lowering water potential of outside environment so microorganisms lose water.

Adding sugar same principle with water potential.

Freeze foods to slow down…


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