b'CholesterolChapterCholesterol is a type of fat made by your body and found in some food. It is used to build cell walls, make bile acids and sex hormones. Fat from the food you eat is broken down by your body into triglycerides (the main form of fat in the blood) and cholesterol. These are carried in the blood as different types of lipoproteins (a mixture of fats and proteins). About one third of your cholesterol comes from what you eat and the rest is made by your body.Low density lipoproteins (LDLs) take cholesterol to where its needed in the body. LDLs not used by the body build up fatty deposits in blood vessels, leading to heart disease. This is why LDLs are known as bad cholesterol.High density lipoproteins (HDLs) take cholesterol to your liver where its broken down so the body can get rid of it. HDLs are known as good cholesterol.Normally your body balances the cholesterol it makes with the cholesterol it gets from food. However, if you are overweight and/or eat too much fat, the cholesterol level in your blood rises.Types of FatsFat is eaten in three main forms:Saturated fats - usually from animal products such as full-fat dairy products, fatty meats, eggs,poultry with skin and also some oils.Polyunsaturated fats - margarine and some nuts.Monounsaturated fats - usually from plants including some nuts and also from fish.Saturated fats tend to increase your blood cholesterol and some unsaturated fats lower the level.RisksA high fat diet increases the risks of:blocked blood vessels, resulting in:being overweight.- heart attack, stroke, angina, highconstipation and bowel problems.blood pressure, kidney failure.cancer of the colon and rectum.AtherosclerosisAtherosclerosis is the most common underlying problem in heart and blood vessel disease. It occurs when the fatty material called atheroma builds up on the inside surface of arteries. The vessels become narrower, harder and less elastic, which restricts blood flow and sometimes block.Heart attack and stroke can result when the vessels supplying blood to the heart and brain are blocked. Atherosclerosis, once considered part of the ageing process, is accelerated by high blood pressure, smoking and a diet high in saturated fats.26 How Your Body Works'