OCR Biology- AS- Food and Health

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Module 2: Food and Health

2.2.1 Diet and Food Production

a) A balanced diet is one that contains all the nutrients required for health in appropriate proportions.

b) Malnutrition is caused by an unbalanced diet. One of the biggest forms of malnutrition is obesity which is caused by consuming too much energy. This is then stored as fat in the adipose tissues. It is defined as someone who has a BMI (body mass index) of over 30.

c) CHD stands for Coronary Heart Disease. This occurs when fatty substances are deposited in the walls of the coronary arteries. This is known as atherosclerosis. The deposits narrow the lumen of the coronary arteries restricting blood flow to the heart muscle which may lead to oxygen starvation. Too much salt decreases the water potential of blood leading to hypertension which can ultimately damage the lining of the arteries leading to atherosclerosis. Saturated fats are also unhealthy although unsaturated fats found in olive oil are beneficial.

d) Cholesterol is found in two types of lipoprotein. High density lipoprotein (HDL) and Low density lipoprotein (LDL)