Balanced diet

Balanced diet

Supplies all the essential nutrients, plus fibre and water.
There are five important nutrients.
1. Carbohydrates - provide energy
2. Fats (lipids) - act as an energy store, provide insulation, make up cell membranes, physically protect organs.
3. Proteins - Needed for growth, the repair of tissues and to make enzymes.
4. Vitamins - Different vitamins have different functions, e.g. vitamin D is needed for calcium absorption, vitamin K is needed for blood clotting.
5. Mineral salts - Different mineral salts have different functions. Iron is needed to make haemoglobin in the blood, calcium is needed for bone formatio
Fibre - Aids movement of food through the gut.
Water - It is used in chemical reactions. We need a constant supply to replace water lost through urinating, breathing and sweating.
Not getting the right amount on each nutrient causes malnutrition
Malnutrition - Having too little or too much of some nutrients in your diet. There are three causes.
1. Not having enough food - you get too little of every nutrient
2. Having an unbalanced diet.
  1. Getting too little of a nutrient can lead to all kinds of deficiency illnesses, e.g. getting too little iron in your diet causes anaemia.
  2. Getting too many carbohydrates or fats can lead to obesity.
3. Not being able to absorb the nutrients from digestion into your bloodstream properly.
  1. E.g. Coeliac disease reduces absorption of nutrients from the small intestine. This also causes deficiency illnesses.
Over-nutrition and Lack of Exercise can lead to Obesity.
1. Obesity is a common dietary condition caused by eating too much food.
  1. Obesity is defined as being 20% or more over the recommended body weight.
  2. Too much sugary or fatty food and too little exercise are the main causes
  3. Obesity can also be caused in people who have an underactive thyroid gland, but it isn't common.
  4. Obesity increases the risk of hypertension (high blood pressure), diabetes, arthritis, coronary heart disease (CHD) and even some forms of cancer.
An unhealthy diet can increases the risk of coronary heart disease (CHD).
1. CHD is caused by reduced blood flow to the heart.
  1. ATHEROSCLEROSIS - narrowing and hardening of the coronary arteries (blood vessels that supply the heart)/
    1. Cause 1 - Diet high in saturated fat raises the blood cholesterol level, increasing the build up of fatty deposits in the arteries (atheromas).
    2. Cause 2 - Diet high in salt can cause high blood pressure, This can damage artery walls.
2. CHD can lead to chest pain (ANGINA) and heart attacks.
The body regulates blood cholesterol level using HDLs and LDLs
1. Cholesterol is a lipid made in the body.
2. Some cholesterol is needed for the body to function properly.
3. Cholesterol needs to be attached to a protein to be moved around, so the body forms lipoproteins - substances composed of both protein and lipid.
4. High Density Lipoproteins (HDLs) are mainly protein. They transport cholesterol from body tissues to the liver where it's recycled or excreted.
  1. Reduce blood cholesterol when the level is too high.
5. Low Density Lipoproteins (LDLs) are mainly lipid. Transport cholesterol from the liver to the blood, where it circulates until it's needed by cells.
  1. Increase blood cholesterol when the level is too high.
6. Diet high in saturated fat raises LDL level. More cholesterol transported to the blood, increasing total blood cholesterol and increasing risk of CHD.
7. Diet high in polyunsaturated fat raises HDL level. More cholesterol transported from blood to the liver.
  1. Total blood cholesterol decreases and the risk of CHD decreases.

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	Created by Shauna Lake about 11 years ago